No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The effect of different surface treatments on bond strength between leucite reinforced feldspathic ceramic and composite resin
Abstract
The aim of this study was to evaluate the effect of different surface treatments on the microtensile bond strength between a leucite reinforced glass-ceramic and composite resin.
Leucite reinforced ceramic blocks (n=24) were constructed using the hot pressing technique. The blocks were assigned to 4 groups, which received the following surface treatments: G1: hydrofluoric (HF) acid and silane; G2: silane alone; G3: HF acid and silane then dried with warm air (100 degrees C); G4: silane alone then dried with warm air (100 degrees C). Unfilled resin was applied, followed by composite resin. Specimens were prepared and loaded in tension to determine the microtensile bond strength. Failure modes were classified by stereo- and scanning electron microscopy (SEM). Data was analysed using Kruskal-Wallis test followed by the Dunn's multiple range test.
The groups including the warm air step (G3 and G4) achieved a significantly stronger adhesion than G1 and G2. Pre-treatment of the surface with hydrofluoric acid in G1 resulted in significantly higher bond strength than G2. Failures were mostly cohesive in the luting resin for G1, G3 and G4 and mainly adhesive at the ceramic-resin interface in G2.
The method of application of silane to the ceramic surface can have a significant influence on the adhesion between the ceramic restoration and the resin cement. Enhancing the condensation reaction by drying the silane with a 100C warm air stream significantly improved the microtensile bond strength, possibly eliminating the need for the hydrofluoric acid etching step.
... An important advantage is that repairing a partially defective restoration prolongs the tooth retention time [6]. Removal of indirect restorations itself is usually not possible without harmful effects for the tooth or to the restoration [7]. Repair is a more low-cost procedure and preserves the tooth tissue better compared to replacement of the restoration [8]. ...
... The defective surface of CAD/CAM resin-based composites should be pretreated before the application of repair materials [9]. Various surface pretreatment methods such as chemical etching with hydrofluoric acid (HF), tribochemical silica coatings, air abrasion, roughening with diamond burs or combinations of any of these techniques are employed to roughen the surface to obtain a better adhesion [7,9,10]. Recently, an alternative approach involves the use of lasers such as Er:YAG lasers [5], Nd:YAG lasers [11] and femtosecond lasers [12] for the surface pretreatment of indirect restorations. ...
... Inorganic components of the CAD/CAM blocks could be primed with silane or phosphoric monomers of this adhesive system [25]. Silane agents form a chemical bond between inorganic and organic surfaces, increase the wettability of the surfaces and thereby promote adhesion [7]. Yoshihara et al. [26] reported that separate silane application was more effective than incorporating a silane agent into universal adhesives. ...
This study aimed to investigate the effects of different powers of Er:YAG laser irradiation on the shear bond strength (SBS) of repaired CAD/CAM resin-based composite materials. A total of 180 CAD/CAM resin-based composite specimens (5 × 5 × 2 mm) were obtained (Shofu Block HC—SB; Grandio Blocs—GB). They were allocated into six groups according to surface pretreatment methods: no surface pretreatment (control), hydrofluoric acid (HF), diamond bur and 3 W, 5 W, and 7 W Er:YAG lasers (20 Hz) (n = 15). Silane and universal adhesive were applied. The repair procedure was completed with nano-ceramic composite resin (Ceram-X Sphere TEC-One). The samples were thermocycled for 10,000 cycles (5–55 °C). The SBS was evaluated with a universal test machine (1 mm/min). A 3D optic profilometer was used to assess the surface topography. Statistical analysis was performed with a two-way ANOVA and Bonferroni tests (p < 0.05). For SB samples, HF and diamond bur caused significantly higher SBSs than 3 W and 7 W lasers, while for GB samples, they led to a significantly higher SBS than all laser treatments. For SB samples, the 5 W laser led to the highest SBS, while for GB samples, the 7 W laser caused the highest SBS (p < 0.05). For both blocks, adhesive failure was more common for the 3 W laser, and a decrease in adhesive failures and an increase in mixed failures were observed with increasing laser irradiation. The 3D optic profilometer revealed that smoother surfaces were obtained with the 3 W laser than other laser irradiation at different powers. Pretreatment with increasing Er:YAG laser powers led to similar bond strengths to hydrofluoric-acid- and diamond-bur-treated CAD/CAM resin-based composite materials. A more powerful laser treatment is required to provide a higher bond strength for restorative materials containing a higher inorganic ceramic content.
... After reading the full text, nine articles were excluded due to several reasons: in (4), the bond strength was not evaluated [18,[30][31][32]; in (4), a warm air stream was not tested [33][34][35][36]; and (1) was a thesis [37]. Then, a total of 28 articles were included in the qualitative analysis [12][13][14]16,20,21,23,24,29,[38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56]. One study was excluded from the meta-analysis because there were no more studies for comparison [53]. ...
... After silane application, the restoration can be heat-treated for 2 min at 100 • C in an oven, allowing the removal of solvents along with other by-products on the ceramic surface, thus fulfilling the reaction of condensation between silane and silica. After that, the adhesion will be stronger and more effective due to the formation of many covalent bonds on the surface of the ceramic [46,96]. The same result can be obtained by the application of hot air at 50 ± 5 • C for 15 s [97]. ...
... Likewise, Shen et al. discovered that silane drying with a stream of warm air (45 • C) improved the bond strength of glass ceramic [29]. Thus, the bond between the ceramic and the resin is significantly strengthened when a drying step is added to the application of silane at 100 • C [46]. Heat treatment at high temperatures (70-80 • C) for silane coupling agents might not be suitable for dental chair-side operations. ...
Any excess solvent from dental adhesive systems must be eliminated prior to material photopolymerization. For this purpose, numerous approaches have been proposed, including the use of a warm air stream. This study aimed to investigate the effect of different temperatures of warm air blowing used for solvent evaporation on the bond strength of resin-based materials to dental and nondental substrates. Two different reviewers screened the literature in diverse electronic databases. In vitro studies recording the effect of warm air blowing to evaporate solvents of adhesive systems on the bond strength of resin-based materials to direct and indirect substrates were included. A total of 6626 articles were retrieved from all databases. From this, 28 articles were included in the qualitative analysis, and 27 remained for the quantitative analysis. The results of the meta-analysis for etch-and-rinse adhesives revealed that the use of warm air for solvent evaporation was statistically significantly higher (p = 0.005). For self-etch adhesives and silane-based materials, this effect was observed too (p < 0.001). The use of a warm air stream for solvent evaporation enhanced the bonding performance of alcohol-/water-based adhesive systems for dentin. This effect seems to be similar when a silane coupling agent is submitted to a heat treatment before the cementation of a glass-based ceramic.
... The chemical bond between ceramic and composite resin is mainly caused by silane coupling agents; by forming a siloxane bond in response to an increase in the surface energy of the ceramics and the wettability of the cement, silane coupling agents establish adhesion between the inorganic phase of the ceramic and the organic phase of the bonding agent applied to the ceramic surface, resulting in microscopic interactions between both parts [19]. Hydrofluoric acid (HF) etching is one of the most prevalent ways to efficiently bond resin to the surface of glass ceramics [16,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. Cementation of glassy matrix ceramics following HF etching and silanization has been recommended in several studies [17,19,27]. ...
... The Er:YAG laser wavelength is 2940 nm, which corresponds to the maximum of water absorption at the invisible spectrum [18,29]. Heat treatment may accelerate the silane, resulting in a long-lasting bond that strengthens the composite-ceramic link [3,5,13,19,[27][28][29][30][31][32][33][34][35]. Water, alcohol, and additional particles are removed from the ceramic surface during heat treatment; the removal of water accelerates the completion of the silane/silica surface condensation reaction and increases the creation of covalent silane/silica bonds. ...
... Evaporation of chemicals that would ordinarily hydrogen bond to the silica surface, such as alcohol, increases the number of bond sites available for interaction with silane [32,33]. Some methods have been described for the heat treatment, and the most common ones include drying with warm air [3,32,33], rinsing with hot water [13,31], using a preheated furnace or hot air oven [5,19,32], and a combination of these methods [15,33]. ...
In the current study, we evaluated the effects of heat treatment (by Er:YAG or furnace) and various surface treatments on the microtensile bond strength (μTBS) of silanized lithium disilicate ceramic. Seventy lithium disilicate (IPS e. max Press; Ivoclar Vivadent) and composite resin (Tetric N-Ceram; Ivoclar Vivadent) blocks were made and distributed into seven groups (n = 10) at random: S: silanization alone; ALS: airborne particle abrasion (APA) and silanization; SC: APA modified with silica and silanization; SHT1: silanization and heat treatment by Er:YAG; SHT2: silanization and heat treatment performed in the furnace (100 °C, 1 min); HF: etching with HF; and HFS: etching with HF and silanization. Every ceramic specimen was cemented to a composite resin block after surface treatment. Cemented specimens were embedded into acrylic resin and were tested with the μTBS test. Data were analyzed using one-way ANOVA and Tamhane T2 tests (α = 0.05). The SHT1 group had the highest bond of strength compared to the other groups (27.46 MPa). The ALS group had the lowest strength of the groups (15.56 MPa). Between SHT2 and HFS (p = 1), the comparison of the mean µTBS values showed no significant differences. It was concluded that silane heat treatment increased the resin composite–ceramic bond strength; however, within the terms of μTBS, the Er:YAG laser treatment was more successful than other surface treatment applications.
... That is why some authors exert efforts on improving the chemical bond between dental ceramics and composite resin provided by the silane coupling agents, thus trying to eliminate the use of HF acid. Silane treatment with heated airflow or in an oven is one of the most frequently used methods [17][18][19][20]. The proposed heating temperatures vary from 38 to 100°C. ...
... This temperature was the most efficient treatment method, providing the highest bond strength among all heating temperatures. According to some studies, HF's effect in the bonding procedure could be compensated by micromechanical roughening of the ceramic restoration and silane heat treatment to obtain high bond strength [17,18]. Despite the large number of in vitro studies in the literature, there is still a lack of clinical evidence of these methods' effectiveness in vivo. ...
... Recommended temperatures vary among different authors. Fabianeli et al. and Roulet et al. propose 100°C heating temperature [17,32]. Monticelli et al. use 38°C [33]. ...
A four-year follow-up of a novel silane heat treatment method for bonding lithium disilicate overlays to tooth structures without hydrofluoric acid etching of the ceramic surface is presented in this case report. Silane heat treatment modifies the silane layer and thus enhances resin ceramic bond strength without hydrofluoric acid etching. The standard ceramic preparation technique prior to bonding silicate ceramics to tooth structure is hydrofluoric acid etching and applying a silane coupling agent, followed by dental adhesive. In this case, the micromechanical roughening of the ceramic surface was performed by air abrasion with Al2O3. Silane heat treatment with constant 120°C airflow, applied for 60 sec, followed by dental adhesive application enhanced the resin-ceramic bond strength. After a four-year follow-up, the restorations’ clinical appearance could be defined as excellent/very good according to the FDI clinical criteria for the evaluation of direct and indirect restorations. This clinical result supports many in vitro studies regarding the resin-ceramic bond strength and durability obtained through postsilanization heat treatment.
... The bond strength between ceramic restorations and the dental remnant is a subject widely studied in the scientific literature. 1,2 Proper bonding between ceramic and resin cement depends on the chemical adhesion between both structures, and, on the micromechanical retention produced by the surface roughness. 3 Many methods have been reported to increase the bond strength, for example, sandblasting with aluminum oxide particles, active application of the silane agent, silane heating, acid etching, and irradiation with high power lasers. ...
... According to previous studies, the silane heating exposes deeper and stable layers, favoring the achievement of a more durable bonding. However, there is a divergence regarding the improvement 2,22 or not 1 of the bond strength after silane heating. The lack of confirmation and protocol to heat the silane (oven, jet of hot air, jet of hot water), makes it difficult for dentists to use this technique. ...
... The lack of confirmation and protocol to heat the silane (oven, jet of hot air, jet of hot water), makes it difficult for dentists to use this technique. 1,2,11 In this study, two silane application techniques were employed. One of them, used in the Control; Er, and Nd groups, consists of the application of silane after conditioning with HF, being a widely used procedure, with good results. ...
Investigate the tensile bond strength, surface morphology and wettability of reinforced glass‐ceramic etched with high power laser at different protocol and luted to human dentin. Fifty carious‐free human molars were used in this study and distributed in 5 groups according to surface etching: (Control [HF10% + Silane]; Er [Er: YAG + Silane]; Sil+Er [Silane + Er: YAG]; Nd [Nd: YAG + Silane] and Nd + Sil [Silane + Nd: YAG]). After, the tensile bond strength test was performed. Three specimens per group were used to perform the surface morphologies by using SEM analysis and wettability by using the sessile drop technique. Failure modes were determined. Data were analyzed with two‐way analysis of variance (ANOVA) and Tukey tests, with α=0.05. The bond strength data showed statistically significant differences among tested groups for the laser and silanization technique type (P < 0.001). The highest calculated bond strength values were obtained with Er (19.25±3.70 MPa) followed by Sil+Er (14.11±4.11 MPa), Control (9.42±2.27 MPa), Nd (9.66±2.02 MPa) and Nd+Sil (6.71±1.88 MPa) respectively. The silane application prior to the laser irradiation showed an inferior bond strength compared to the conventional silanization technique. The surface etching using Er: YAG laser showed promissor results for the lithium disilicate.
... We therefore hypothesize that warm air-drying could enhance the durability by facilitating solvent evaporation [16,17]. In addition, the hydrolysis of silanes is dependent on temperature [6], so warm air could also contribute to the activation of the silane and thus improve the bonding performance [18][19][20][21]. ...
... Therefore, the effect of warm air-drying was examined, because it could promote chemical bonding to glass ceramics. A previous study reported that drying of γ-MPTS with hot air (100 °C) for 1 min significantly increased the micro-tensile bond strength of resin composite to leucite reinforced glass ceramics [18]. Another study examined the effect of heat treatment of CP in an oven (100 °C) for 2 min or using warm air (50 °C) for 1 min and revealed that both methods were effective in increasing the bond strength of a resin cement to glass ceramics [20]. ...
... Another study examined the effect of heat treatment of CP in an oven (100 °C) for 2 min or using warm air (50 °C) for 1 min and revealed that both methods were effective in increasing the bond strength of a resin cement to glass ceramics [20]. The former study showed that the heat treatment even outperformed HF etching combined with normal air-dried silane [18], while the latter showed no significant difference between them [20]. A significant improvement in bond strength was also reported after warm air-treatment (45 ± 5 °C) of a silane coupling agent for 2 min, but the bond strength was still significantly lower compared to that of HF etching [19]. ...
Background: Repair bonding to lithium disilicate ceramic (LDS) remains an issue. This study examined whether the adaptation of a resin composite to LDS can be improved by a silane pretreatment and warm air-drying. Methods: LDS blocks (IPS e.max CAD) with prefabricated tapered cavities were bonded using a silane-containing universal adhesive (Clearfil Universal Bond Quick ER; UBQ) or the bonding agent of a two-step self-etch adhesive (Clearfil SE Bond 2), with and without a silane pretreatment (Clearfil Ceramic Primer; CP). CP and the adhesives were air-dried with normal air (23 ± 1 °C) or warm air (60 ± 5 °C), light-cured, and the cavities were filled with a flowable composite. Interfacial gap formation was evaluated using swept-source optical coherence tomography immediately after filling, after 24 h, 5000 and 10,000 thermal cycles, and an additional 1 year of water storage. Results: Without the silane pretreatment, all specimens soon detached from the cavities. Warm air-drying significantly decreased gap formation compared to normal air-dried groups (p < 0.001) and improved long-term stability (p < 0.001). The lowest gap formation was observed with UBQ when the silane pretreatment was combined with warm air-drying. Conclusions: Composite adaptation to LDS was insufficient without silanization, but it was stable in the long term if the silane pretreatment and warm air-drying were combined.
... When luting glass ceramic restorations to tooth substrates, hydrofluoric acid etching has been conventionally used to create a superficial microstructure on the surface and promote micromechanical interlocking with resin luting materials 3) . However, this step is not applicable for the repair of ceramic restorations in the oral environment because the use of hydrofluoric acid is hazardous 4) . ...
... A previous study reported that the reaction rate of silane hydrolysis was more than 6 times higher when temperature was increased from 20°C to 50°C 15) . In dentistry, warm airblowing of silane coupling agents was reported to enhance Long-term evaluation of warm-air treatment effect on adaptation of silanecontaining universal adhesives to lithium disilicate ceramic bonding to glass ceramics 3,8) and glass fiber posts 16,17) . However, studies about effect of heat treatment on the bonding performance of silane-containing universal adhesives to glass ceramics are scarce. ...
... However, just oneday storage of the mixture reverted the positive effect 11) which demonstrates instability of the silane in the acidic conditions of universal adhesives. Warm air-blowing of silane coupling agents was previously proven to improve the adhesion to glass ceramics 3,8) and glass fiber posts 16,17) due to the acceleration of the silane hydrolysis reaction 14) . In this study, warm air (60±5°C) was delivered using a heat blower to increase the temperature of silane-containing universal adhesives applied to lithium disilicate ceramics. ...
The effect of warm air-blowing on the sealing ability of two one-bottle and one two-bottle silane-containing universal adhesives (UAs) applied to lithium disilicate ceramics (LDS) was evaluated. Tapered cavities prefabricated in LDS blocks (IPS e.max CAD) were treated by the adhesives, air-blown either with normal air (23±1°C) or warm air (60±5°C), and filled with a flowable resin composite. Interfacial gap formation was observed using swept-source optical coherence tomography immediately after filling, after 24 h, 5,000 and 10,000 thermal cycles, and an additional 1-year water storage. Specimens bonded using normal air-blown one-bottle UAs exhibited a significantly higher gap formation than the two-bottle UA (p<0.001), and detached within 24 h. Warm air-blowing significantly decreased the gap formation of one-bottle UAs (p<0.001), but the specimens dislocated within 24 h or during thermocycling. The two-bottle UA withstood all aging procedures and warm air-blowing significantly decreased its 1-year gap formation compared to normal air-blowing (p=0.002).
... (6,7) Their clinical success as dental restorations is determined by bond durability and strength of the resin cement to the ceramic material and to tooth structure. (8)(9)(10)(11) Stewart et al. (2002) (12) and Fabianelli et al (2010), (13) reported that during bonding ceramic to tooth structure, the enamel or dentin/cement interfaces as well as the ceramic/cement interface should be optimized as the weaker one will determine the restoration's final bond strength. Failure of the adhesive seal in any of these interfaces, results in microleakage jeopardizing the longevity and clinical performance of the restorations, causing stains, recurrent caries, sensitivity adverse pulp response and ends with restoration debonding. ...
... Silanation helps for the chemical adhesion between the organic and inorganic substances, producing a strong and durable adhesive bond between the ceramic and the resin cement. (13,32) Silane coupling agent bonds resin composites to silica-based ceramics. (30,33) During composite resin curing, an addition polymerization reaction occurs between the methacrylate groups of the resin matrix and silane bifunctional groups. ...
... These by-products were accused of weakening the bond strength with resins. (13,39,40) Monobond-S primer is recommended by the manufacturer to be used with variolink resin cement. ...
Objective: The aim of this study was to evaluate the micro-shear bond strength between a dual cured resin cement and five different types of ceramics in composition and techniques of construction, using two different surface treatments. Materials & methods: A total of 50 ceramic disks were made and divided into 5 equal groups according to material type IPS Empress CAD, IPS e.max Press, IPS e.max CAD, Vita Suprinity and PM9 (n = 10). Each group was subdivided into 2 subgroups according to surface treatment they will be subjected to (n=5). Subgroup I: Bonding surfaces were etched with 5% HF acid, then coated with Monobond S. Subgroup II: Monobond Etch & Prime was applied on the bonding surfaces. For standardization of bonding surface area, 5 plastic tubings distributed on the bonding surface of each disk were used to place the dual resin cement. The samples were then subjected to micro-shear bond strength. Results: Results showed insignificant difference in micro-shear mean values between the IPS Empress CAD subgroups while significant differences were found between the other subgroups within the same group. Monobond Etch & Prime surface treatment resulted in higher micro-shear bond strength compared with HF surface treated subgroups for all the tested materials except for the PM9 and IPS e.max CAD. Conclusions: It was found that ceramic microstructure as well as the fabrication technique affects the selection surface treatment type. Also, Monobod Etch and Prime as a single step surface treatment produced clinically accepted and comparable results to that of HF treatment.
... The implementation of heat treatment protocols prior to adhesive cementation has been suggested to improve the properties of the silane-coupling agent [7][8]. This pre-treatment helps eliminate water, alcohol, and other by-products from the ceramic surface, in addition to assisting in the completion of the condensation reaction between silica and silane, promoting the formation of a covalent bound at the ceramic-silane interface, consequently increasing the effectiveness and durability of the adhesion [7][8]. ...
... The implementation of heat treatment protocols prior to adhesive cementation has been suggested to improve the properties of the silane-coupling agent [7][8]. This pre-treatment helps eliminate water, alcohol, and other by-products from the ceramic surface, in addition to assisting in the completion of the condensation reaction between silica and silane, promoting the formation of a covalent bound at the ceramic-silane interface, consequently increasing the effectiveness and durability of the adhesion [7][8]. ...
... Some authors have demonstrated an effective bond strength when only heat treatment of silane is performed [8,[13][14]. However, according to the results obtained in the present study, the heat treatment of silane at 100ºC for 2 min is effective to maintain the bond strength after aging between resin cement and feldspathic ceramic when associated with prior treatment using 10% hydrofluoric acid. ...
Objective
Evaluate the influence of silane heat treatment in bond durability between two resin cements and CAD/CAM feldspathic ceramic.
Methods
40 feldspathic ceramic blocks were obtained, and were duplicated in microhybrid composite. All ceramic blocks were etched with 10% hydrofluoric acid for 20 s and received application of silane agent. The blocks were randomizedinto eight groups (n=5) according to the surface treatments and luting agents: P- Panavia F; PAg- Panavia F + Aging; HP- Heat Treatment + Panavia F; HPAg- Heat Treatment + Panavia F + Aging; R- RelyX ARC; Rag- RelyX ARC + Aging; HR- Heat Treatment + RelyX ARC; HRAg- Heat Treatment + RelyX ARC + Aging. The heat treatment was performed in furnace at 100 °C for 2 min. All blocks were cemented and cut to obtain samples with adhesive area of 1 mm2. Aging was performed with 10000 thermal cycles. The samples were subjected to microtensile bond strength test.
Results
The three-way ANOVA test revealed a significant interaction between cement versus heat treatment (p=0.001) and heat treatment versus thermal cycling (p=0.001) indicating that there was a change in bond strength due to surface treatment and aging.
Conclusion
Therefore, the heat treatment of the silane at 100 ºC for 2 minutes obtained higher values of bond strength between the resin cement and a feldspathic ceramicafter aging.
... In spite of its brittleness and limited flexural strength of silica-based ceramics, final adhesive cementation with composite influenced the fracture resistance of the ceramic restoration and the abutment tooth positively. (5,6) A bond strength depends on micromechanical interlocking and chemical bonding to the ceramic surface, roughening and proper cleaning are needed for adequate surface activation (7,8) Using hydrofluoric acid and silane coupling agent together on the surface of the ceramic was claimed to increase the bond strength between the tooth substrate and the ceramic restoration when using resin cement (9,10) . However, it has been shown that following hydrofluoric acid removal from the ceramic surface, post etching remnants are formed, which may has an effect on the bond strength (11) . ...
... Hydrofluoric acid etching istargeting only the silicate particles in the glass matrix that's why it's broadly used with fieldspathic glass ceramics producing hexaflourosilicates thus creating a porous surface to enhance the micromechanical bonding with resin cement (17,19,23,24) . surface etching with hydrofluoric acid at a concentration of 9% to 10% (12,25,26,27,28) and etching time ranged between one (9,12,14,19,29) and two minutes was the recommended protocol for pretreatment of feldspathic ceramics (14,19) . In the present study 9% of hydrofluoric acid was applied for one minute. ...
... Following etching of silica-based ceramics, it has been dimonstrated that hydrofluoric acid leads to the formation of insoluble byproducts, such as silica and fluoride salts which may remain on the ceramic surface (9) . These remnants may interfere with the bond strength between the ceramic and the substrate onto which it is cemented (9,30,31). ...
... (6,7) Their clinical success as dental restorations is determined by bond durability and strength of the resin cement to the ceramic material and to tooth structure. (8)(9)(10)(11) Stewart et al. (2002) (12) and Fabianelli et al (2010), (13) reported that during bonding ceramic to tooth structure, the enamel or dentin/cement interfaces as well as the ceramic/cement interface should be optimized as the weaker one will determine the restoration's final bond strength. Failure of the adhesive seal in any of these interfaces, results in microleakage jeopardizing the longevity and clinical performance of the restorations, causing stains, recurrent caries, sensitivity adverse pulp response and ends with restoration debonding. ...
... Silanation helps for the chemical adhesion between the organic and inorganic substances, producing a strong and durable adhesive bond between the ceramic and the resin cement. (13,32) Silane coupling agent bonds resin composites to silica-based ceramics. (30,33) During composite resin curing, an addition polymerization reaction occurs between the methacrylate groups of the resin matrix and silane bifunctional groups. ...
... These by-products were accused of weakening the bond strength with resins. (13,39,40) Monobond-S primer is recommended by the manufacturer to be used with variolink resin cement. ...
... This study has argued that once applied on ceramic surface, 4-META reacts with surface moisture and turns into 4-methacryloxyethyl trimellitate (4-MET); so, silane becomes activated and hydrolysis leads to formation of silanol groups that bind the ceramic by forming a siloxane structure. [11] It has been argued that heat treatment removes alcohol, water, and other byproducts from the ceramic surface and thus facilitates the completion of silicate silane condensation reaction and formation of covalent bond between silane and ceramic; [7,14] this leads to a durable and reliable composite-ceramic bond without the need of micromechanical retention. [15] Previous studies have tested the effect of different heat treatment methods and temperatures, such as heating in oven at 100°C for 2 min, at 100°C for 5 min, at 77°C for 1 min, rinsing with hot water and hot air on bond strength. ...
... [15] Previous studies have tested the effect of different heat treatment methods and temperatures, such as heating in oven at 100°C for 2 min, at 100°C for 5 min, at 77°C for 1 min, rinsing with hot water and hot air on bond strength. [6,14,[16][17][18] Several studies have reported the effect of heat treatment on different silanes, but its effect on silanes containing 4-META is unknown. This paper reports the results of an in vitro study on the effect of heat treatment and acidic monomer 4-META to silane on microtensile bond strength of dual-cured resin cement to IPS e.max CAD ceramic. ...
... [30] Several other studies also reported the positive effect of heat treatment and rinsing with hot water on bond strength of ceramic and resin cement even after storage of specimens and exposure to thermal cycles. [14,31] This positive effect is possibly due to enhancement of cross-linking network and removal of physisorbed and chemisorbed areas of surface layer leading to better exposure of reactive areas near the ceramic surface. [32] In other words, the effect of heat treatment on the efficacy of silane could be due to improvement of cross-linking, prevention of water penetration in silane layer, [16] oligomerization via bonding of glass matrix to silane agent, [33] evaporation of solvent and residues of silanol hydrolysis, and finally, formation of extensive internal pressure gradients. ...
Background: Silane promotes bonding between ceramic and resin cement. Silane function could be improved by heat treatment and adding 4-Methacryloxyethyl trimellitate anhydride (4-META). The aim of this study was to assess the effect of heat treatment and adding 4-META to silanes on the microtensile bond strength of IPS e.max CAD ceramic and resin cement.
Materials and Methods: In this in vitro study, 32 IPS e.max CAD blocks (6 mm × 6 mm × 4 mm) were randomly divided into 8 groups of 4. The ceramic surfaces were etched by 10% hydrofluoric (HF) for 20 s, and Clearfil Ceramic Primer Plus, Clearfil Porcelain Bond Activator (CPA) +4-META, CPA + Clearfil SE Bond (CPA + SE), and Bis-Silane with and without Oven drying at 100°C for 5 min were applied on the ceramic surfaces as silanes, and then, the ceramics were bonded to composite disks by dual-cured resin cements. Ultimately, a total of 120 sticks ( 1 mm × 1 mm × 8 mm) were subjected to microtensile bond strength test (15 sticks from each group) and the failure types were assessed by stereomicroscope at 40x. Data were analyzed by two-sided analysis of variance test and Student's t-test the P values were considered to be < 0.05.
Results: The Bis Silane group (two bottles) showed maximum bond strength (P = 0.009). Heat treatment significantly reduced the bond strength in Bis Silane (P = 0.0001); but, in other groups, it did not show significant effect on the bond strength. Adding 4-META to CPA did not significantly affect the microtensile bond strength of IPS e.max CAD ceramic to resin cement, and there was no difference in mode of failure between groups.
Conclusion: The effect of silane type was significant on the microtensile bond strength of the ceramic to resin cement. The effect of 4-META on the bond strength was not significant. The interaction between silane type and heat treatment on the bond strength of ceramic to resin cement was also significant.
... 14,15 resulting in a rough ceramic surface that provides increased micromechanical retention with the resin cement. 14,16 In addition, the increased roughness increases the surface energy and the interaction between the bonding agent and silane, 15,17 thus promoting a chemical-mechanical adhesion at the ceramic / silane / cement interface. ...
... 17 These factors may also alter the bond strength between resin cement and glass ceramics. 15,16,17,18,19,20,21 As an example, the exposure of lithium disilicate to HF for more than 20 seconds may lead to the weakening of its structure. 17,18,19 As for feldspathic ceramics, an acid conditioning time ranging from 1 to 2 minutes is recommended. ...
... 17,18,19 As for feldspathic ceramics, an acid conditioning time ranging from 1 to 2 minutes is recommended. 16,20,21 Additionally, restorations with disilicate ceramic restorations can be fabricated by the press technique, where ceramic ingots are melted and injected into the mold in a specific furnace. Differently, through the CAD / CAM technique, the partially sintered block of disilicate is milled and its final resistance only occurs after its complete sintering. ...
The objective of this study was to evaluate the effect of the hydrofluoridric acid (HF) concentration and time of acid conditioning on bond strength of three glass ceramics to a resin cement. Thus, fifty blocks (10 mm x 5 mm x 2 mm) of each ceramic (LDCAD: IPS e.max CAD; LCAD: IPS Empress CAD and LDHP: IPS e.max Press) were made and embedded in acrylic resin. The surfaces were polished with sandpaper (#600, 800, 1000, and 1200 grits) and blocks were randomly divided into 15 groups (n = 10) according to the following factors: Concentration of HF (10% and 5%), conditioning time (20 s and 60 s) and ceramic (LDCAD, LDHP, and L). After conditioning, silane (Prosil / FGM) was applied and after 2 min, cylinders (Ø = 2 mm; h = 2 mm) of dual resin cement (AllCem / FGM) were made in the center of each block using a Teflon strip as matrix and light cured for 40 s (1,200 mW/cm2). Then, the samples were thermocycled (10,000 cycles, 5/55°C, 30s) and submitted to the shear bond test (50 KgF, 0.5 mm/min). The data (MPa) were analyzed with 3-way ANOVA and Tukey's test (5%). Failure analysis was performed using a stereomicroscope (20x) and a scanning electron microscope (SEM). ANOVA revealed that the “concentration” factor (p = 0.01) and the interaction “acid concentration X ceramic” (p = 0.009) had a significant effect, however, the “ceramic” (p = 0.897) and “conditioning time” (p = 0.260) factors did not influence the results. The LDHP10%60s (10.98 MPa)aA* group presented significantly higher bond strength than LDHP10%20s (6.57 MPa)bA, LCAD5%20s (6,90 ±3,5)aB and LDHP5%60s (5.66 ± 2,9MPa)aA* groups (Tukey). Failure analysis revealed that 100% of specimens had mixed failure. In conclusion, etching with 5% HF for 20 seconds is recommended for lithium disilicate and leucite-reinforced CAD/CAM ceramics. However, for pressed lithium disilicate ceramic, 10% HF for 60 s showed significantly higher bond strength to resin cement.
... (26,27) A utilização clínica do ácido fluorídrico tem sido questionada, devido a toxidade química, formação de sais insolúveis na superfície cerâmica, que podem interferir na resistência adesiva entre a cerâmica e o cimento resinoso. (28) Em vista disso, tratamentos alternativos para adesão às cerâmicas vítreas têm sido propostos, (29) como a remoção de sais pela limpeza em ultrassom (25) e o aquecimento do silano. (2,(28)(29)(30) Para as cerâmicas cristalinas o condicionamento ácido convencional se mostra ineficaz, sendo contra-indicado; (31) de o ácido fluorídrico a 10% não promove alterações superficiais neste material devido o elevado conteúdo cristalino deste material, apresentando-se ineficaz ao tratamento de superfície da alumina e zircônia. ...
... (28) Em vista disso, tratamentos alternativos para adesão às cerâmicas vítreas têm sido propostos, (29) como a remoção de sais pela limpeza em ultrassom (25) e o aquecimento do silano. (2,(28)(29)(30) Para as cerâmicas cristalinas o condicionamento ácido convencional se mostra ineficaz, sendo contra-indicado; (31) de o ácido fluorídrico a 10% não promove alterações superficiais neste material devido o elevado conteúdo cristalino deste material, apresentando-se ineficaz ao tratamento de superfície da alumina e zircônia. ...
... (41) Pesquisas tem apontado que o tratamento térmico do silano melhora as propriedades adesivas entre a cerâmica feldspática e resina composta e poderia substituir o uso de condicionamento ácido em uma cerâmica vítrea. (2,28,29,30,41,43) Porém, faltam estudos clínicos que comprovem a eficiência deste procedimento. ...
The metal-free restorations are sought out due to aesthetic needs. The success of restorative treatment depends on the peculiarities of each ceramic system and on a proper strategy for cementing. This article presents the surface treatment of the interfaces involved during the cementing, the dental structure and restoration, and elucidates the cementing agent. It emphasizes the different types of surface treatment for acid-sensitive and acid-resistant ceramics, and hybrid ceramics. The literature review was based on scientific articles published in different database (PubMed, Medline, Scielo, Bireme and Google Scholar) using the keywords: prosthodontics, ceramics, surface treatment and cementation. Relevant articles were selected between 2002 and 2015 regarding the issue under review. The knowledge of dentists about the cementation strategies, depending on the type of ceramic used, is necessary for decision making during the cementing and promote the clinical success of treatment with metal-free restorations.
... Hydrofluoric acid dissolves the glassy surface on the ceramic matrix, creating surface pits. Surface etching with hydrofluoric acid and the subsequent application of silane increases the wettability and form covalent bonds between the ceramic and the resin cement 7 . Silane coupling agents establish adhesion, which occurs between the inorganic phase of the ceramic and the organic phase of the bonding agent applied to the ceramic surface 2 . ...
... Despite the functions of hydrofluoric acid, the HF-etching step is not required and can be removed from the ceramic-restoration procedure for the following reasons: (1) HF acid is highly toxic and can pose severe health hazards 8 . (2) Etching silicabased ceramics with HF acid produces insoluble by-products consisting of silica fluoride salts on the surface 7,9 , and the remaining by-products can disrupt the bond strength of the resin 10 . (3) HF acid etching is not suitable for some recently developed glass ceramics with high crystalline structures. ...
Objective: the purpose of this study was to evaluate two different methods of surface treatment; conventional and simplified of three different dental ceramic materials on micro-shear bond strength (MSBS). Materials and methods: 120 resin cement cylinder-shaped samples (1mm in diameter and 2 mm in height) were fabricated, 5 on each ceramic disc (a total of 24 ceramic discs were used with 10 x14 mm² surface area & height of 2 mm), samples were divided according to the type of ceramic plate used into 3 groups (each group n = 40), group I: Resin cement samples cemented on lithium disilicate plate ." IPS e.max Cad", Group II: Resin cement samples cemented on Hybrid ceramic plate "Vita enamic" and group III: Resin cement samples cemented on zirconia reinforced lithium silicate plate "Celtra duo". Each group was subdivided into 2 subgroups according to the technique of ceramic surface treatment (each subgroup n = 20), Subgroup I (Conventional technique using HF+S), Subgroup II (Simplified technique using Monobond Etch & Prime). Then each subgroup was divided into two classes (10 samples each), class I tested for micro shear bond strength (MSBS) without thermocycling, class II tested after thermocycling. Resin cement was mixed and then light-cured according to the manufacturer's instructions. MSBS tests were carried out using universal testing machine (Instron USA). The data were collected, tabulated, and statistically analyzed. Results: It was found that for Emax, the conventional technique (50.1±6.5) showed higher values of MSBS than the simplified technique (42.3±10.5) before thermocycling while the values were (40.7±9.3) for conventional and (37.6±5.6) for simplified after thermocycling without a significant difference. For Vita Enamic, the simplified technique (38±3.7) showed higher values of MSBS than the conventional technique (29.8±3.7) before thermocycling while the values were (32±4.5) for simplified and (25.2±5.8) for conventional after thermocycling with a significant difference. For Celtra duo, the simplified technique (50.6±5.7) showed higher values of MSBS than the conventional technique (41.6±9.4) before thermocycling while the values were (36.3±4.5) for conventional and (21.1±5) for simplified after thermocycling with a significant difference. The difference between groups was statistically tested by Independent samples T-test P value < 0.05 (2) Osama T. Ali, et al.
... Hydrofluoric acid dissolves the glassy surface on the ceramic matrix, creating surface pits. Surface etching with hydrofluoric acid and the subsequent application of silane increases the wettability and form covalent bonds between the ceramic and the resin cement 7 . Silane coupling agents establish adhesion, which occurs between the inorganic phase of the ceramic and the organic phase of the bonding agent applied to the ceramic surface 2 . ...
... Despite the functions of hydrofluoric acid, the HF-etching step is not required and can be removed from the ceramic-restoration procedure for the following reasons: (1) HF acid is highly toxic and can pose severe health hazards 8 . (2) Etching silicabased ceramics with HF acid produces insoluble by-products consisting of silica fluoride salts on the surface 7,9 , and the remaining by-products can disrupt the bond strength of the resin 10 . (3) HF acid etching is not suitable for some recently developed glass ceramics with high crystalline structures. ...
... These alternative strategies are effective and may be used instead of delaying the procedure. Introduction: All-ceramic restorations currently dominate the market of indirect restorative materials due to their biocompatibility, longevity and superior aesthetics [1]. Silica-based ceramics, such as leucite, carry the advantage of being receptive to surface treatments, making them bondable to tooth substrates [2]. ...
... ABSTRACT Introduction: Neurosensory disorders may be considered as a complication from surgical procedures, such as dental implants and mandibular osteotomy [1][2][3]. In these cases, the orofacial damage can involve general and professional patient impairments. ...
Introduction
All-ceramic restorations currently dominate the market of indirect restorative materials due to their biocompatibility, longevity and superior aesthetics [1]. Silica-based ceramics, such as leucite, carry the advantage of being receptive to surface treatments, making them bondable to tooth substrates [2]. However, a standardised application protocol regarding silane coupling agents is lacking. Such step is critical to ensure durability of the restoration placed in situ. Post-etch cleaning and silane application have been proven to increase bond strength, however, this step varies for each material [3]. The aim of this research was to assess the influence of different types of silane coupling agents and respective application times on the bond strength of the ceramic-resin interface.
Materials and methods
Ten leucite reinforced glass ceramic blocks (IPS Empress CAD LT BL4/C 14) were divided into equal halves. Of the samples obtained, 6 were randomly divided into three groups according to the silane used: G1 BIS-Silane (Bisco, Schaumburg, IL, USA); G2 ESPE Sil Silane Coupling Agent (3 M ESPE AG, Seefeld, Germany); G3 Monobond Plus (Ivoclar-Vivadent, Schaan, Liechtenstein). Each was then divided into two subgroups, according to the surface conditioning time: T1 (1 min.) or T2 (5 min.). Each block was acid etched (HF 9.5% − 1 min), post-etching cleaned (OPA 37.5% − 1 min; ultrasonication − 2 min.) and silanized. Heat treatment was carried out at 100 °C (1 min.). Then a thin layer of Optibond FL (Kerr) adhesive was applied and each block was adhered to pre-heated resin at 55 °C. The samples were light cured for 40 s on each side (1200 mW/cm²). Samples were sectioned into microspecimens (1 ± 0.2 mm²) that were subjected to aging (10,000 thermocycles − 5 and 55 °C). The microspecimens were tested in tension at a crosshead speed of 0.5 mm/min, until they debonded. Data analysis was carried out by a two-way ANOVA, at a significance level of 5%.
Results
The group featuring BIS-Silane with longer application time (G1T2) presented a mean µTBS value (32.4 ± 19.6 MPa) significantly higher to all other groups (p < .001). Monobond Plus registered the lowest mean µTBS value (G3T1 − 18.5 ± 7.3 MPa) and (G3T2 − 17.3 ± 5.8 MPa). The type of silane coupling agent has shown to have a significant influence on the microtensile bond strength (p = .001; η²=0.16).
Discussion and conclusions
Some authors have previously suggested that silanization could benefit from longer application times, but seldom research has been found featuring this variation protocol [3,4]. Silanes require a hydrolysation process in order to establish chemical bonds. Two-bottle systems show the highest bond strength results and may benefit from longer application times. The addition of 10-MDP seems to have no significant advantage over traditional silane coupling agents.
... It is a highly toxic substance and diffuses in the cell and poses serious health hazards like tissue necrosis. [9] Newer glass ceramics have a very fine crystalline structure that gets no benefits from HF etching. [10] Furthermore, HF etching of glass ceramics can result in the formation of insoluble silica fluoride salts [9,11] which precipitate on the surface of ceramics acting as a barrier for the resin penetration, thereby hampering adequate bonding. ...
... [9] Newer glass ceramics have a very fine crystalline structure that gets no benefits from HF etching. [10] Furthermore, HF etching of glass ceramics can result in the formation of insoluble silica fluoride salts [9,11] which precipitate on the surface of ceramics acting as a barrier for the resin penetration, thereby hampering adequate bonding. This, in turn, can affect the resin ceramic bond strength. ...
Aim:
This study assessed the effect of postetch cleansing on the surface microstructure, surface topography, and microshear bond strength (μSBS) of lithium disilicate and the resin cement.
Setting and design:
In Vitro analytical study.
Materials and methods:
Fifteen discs (10 mm diameter and 2 mm thickness) were fabricated from highly translucent lithium disilicate IPS Emax 2 ceramic (Ivoclar Vivadent, Schaan, Liechtenstein). Four resin cement (RelyX Ultimate, 3M ESPE) cylinders (0.9 mm diameter and 4 mm high) were placed on each ceramic disc (total n = 60). The samples were divided into three groups based on the surface treatment of the ceramic discs (20 resin cement cylinders on 5 discs in each group). Group I (HF) (control) etched with 9.6% HF with no postetch cleansing, Group II (HFP) etched with 9.6% HF for 20 s followed by rinsing with water and postetching cleansing with 37% phosphoric acid, and Group III (HFPU) etched with 9.6% HF followed by active application of 37% phosphoric acid followed by postetch cleansing in ultrasonic bath for 5 min. μSBS of resin cement to ceramic surfaces was tested following a standard protocol. Surface roughness was evaluated using an atomic force microscope. Surface topography and elemental analysis were analyzed using SEM/EDX. Mode of failure was also assessed.
Statistical analysis used:
The data were analysed using one way analysis of variance and post hoc tukeys test.
Results:
The μSBS were found to be highest for Group III (HFPU), followed by Group II (HFP) followed by Group I (HF) and were statistically significant. There was a difference in the surface topography and surface microstructure between the three groups. Mode of failure was predominantly adhesive.
Conclusion:
The μSBS, surface topography, and surface microstructure were found to be superior in the groups, in which postetch cleansing was done as compared to the control in which no postetch cleansing was done.
... 10 This etched surface also provides a higher surface energy prior to the application of a silane agent, which enhances chemical bonding between the ceramic and a resin material, thereby increasing the functional characteristics of the ceramic. [11][12][13][14] Furthermore, this process promotes greater wettability over a ceramic surface, and this increases the bonding capacity of the surface with resin cements. [15][16][17] Currently, there is no consensus regarding the optimal acid concentration and etching time for the treatment of ceramic surfaces. ...
... These results suggest that the bonding of the cement with the ceramic was very efficient. Moreover, these results are consistent with those reported by Fabianelli et al, 12 in which higher bond strength values predominantly exhibited cohesive failure. In the present study, the groups with the lowest mean microshear bond strength presented both adhesive and mixed failures. ...
Purpose:
To evaluate the effect of different concentrations of hydrofluoric acid (HF) on the surface roughness of a ceramic reinforced by lithium disilicate and on the bond strength formed between the ceramic and self-adhesive resin cement.
Materials and methods:
A total of 100 disks of IPS e.max Press ceramic (Ivoclar Vivadent) reinforced by lithium disilicate were prepared as follows: group 1 remained untreated (control group); in groups 5-20, 5-40, and 5-60, the surfaces were etched with 5% HF for 20, 40, and 60 seconds, respectively; in groups 10-20, 10-40, and 10-60, the surfaces were etched with 10% HF for 20, 40, and 60 seconds, respectively; and in groups 10-20P, 10-40P, and 10-60P, the surfaces were etched with 10% HF for 20, 40, and 60 seconds, respectively, followed by treatment with 37% phosphoric acid for 5 seconds. Surface roughness and bond strength were analyzed with confocal microscopy and microshear testing, respectively. The values obtained were statistically analyzed using paired t test and two-way ANOVA followed by Tukey post hoc test at a 5% significance level.
Results:
Surface roughness was influenced by the concentration and exposure time of acid applied (P < .05) and by the combination of these two factors (P < .05). Treatment with 10% HF for 40 seconds (group 10-40) achieved the highest roughness value. In contrast, bond strength was affected only by the acid exposure time (P < .05).
Conclusion:
Conditioning of lithium disilicate ceramics can change the surface morphology, thereby affecting bond strength with resin cement.
... However, some studies have shown that HF acid etching has the potential to form cracks, which may interfere with the adhesion of resin cements and therefore reduce the bond stability of LD-resin cement [45][46][47]. To minimize these damaging effects of HF acid etching on LD surfaces, subsequent surface treatment using silane coupling agents could ensure a more stable and improved bond strength of LD to resin cements [48][49][50]. ...
The low bond strength of lithium disilicate (LD) ceramics to dental resin cements remains a critical issue for dental applications because it leads to frequent replacement and causes tooth tissue destruction and consumption. The objective of this study was to examine the effects of atmospheric non-thermal argon plasma (NTP) treatment on LD to improve its micro-shear bond strength (μSBS) with dental resin cements because LD mostly experiences shear stress for its commonly used dental applications as crowns or veneers. Argon plasma treatment was performed on hydrofluoric (HF) acid-etched LD surfaces, and then commercial resin cements were subsequently applied to the treated LD surfaces. The plasma treatment significantly reduced the water contact angle of the LD surface to less than 10° without changing the surface morphology. The μSBS test was performed with cement-bonded LD samples after 24 h and 30 days, as well as after 1000 cycles of thermal cycling. The test results show that, as compared with the untreated controls, 300 s of plasma treatment significantly improved the LD-resin cement bond strength by 59.1%. After 30 days of storage in DI water and 1000 cycles of thermal cycling, the plasma-treated LD samples show 84.2% and 44.8% higher bond strengths as compared to the control samples, respectively. The plasma treatment effect on LD surfaces diminished rapidly as the bond strength decreased to 25.5 MPa after aging in the air for 1 day prior to primer and cement application, suggesting that primers should be applied to the LD surfaces immediately after the plasma treatment. These results demonstrate that, when applied with caution, plasma treatment can activate LD surfaces and significantly improve the SBS of LD with dental resin cements in both short-term and long-term periods.
... For this reason, it has been suggested to eliminate the acid etching step so that adhesion occurs exclusively through the application of silane. However, the procedure is still not consensual because some authors believe that only the application of silane would be enough to obtain adequate union between cement and ceramic [12] while others claim that etching with hydrofluoric acid continues to be essential to obtain adhesion [7]. ...
Objectives: The aim of this study was to evaluate the silane application with electric current as an alternative method for surface treatment of acid-sensitive ceramic. Materials and Methods: IPS E.max Press ceramic discs applied with silane, associated or not with hydrofluoric acid, electric current and storage time in water were divided in the groups (n=10) AE+CF (Acid etching + electric current free); AE+CA (Acid etching + electric current); AF+CF (Acid etching free + electric current free); AF+CA (Acid free + electric current); AE+CF +T (Acid etching + electric current free + thermal cycling); AE+CA+T (Acid etching + electric current + thermal cycling); AF+CF+T (Acid free + electric current free + thermal cycling) and AF+CA-T (Acid etching free + electric current + thermal cycling. In the conditioned groups, 10% hydrofluoric acid was applied for 20s. The silane was applied with microbrush in the AE+CF-T, AE+CA-T, AF+CF-T and AE+CA-T groups and in the other groups it was replaced by a metal tip conductor of electric current. Cylindrical silicone matrices with three holes (12 mm in diameter and 1mm thick) were placed on the ceramic. The resin cement RelyX U200 was inserted into the holes of the matrix, subjected to a static load of 250mg for 2min and photoactivated for 20s. After removing the matrix, the sample with resin cement cylinder adhered to the ceramic was stored in an oven at 37 ºC for 24h. The 24-h samples and those thermocycled with 10,000 cycles in vats with water at temperatures of 5±1 ºC and 55±1 ºC were submitted to microshear resistance test, fracture analysis, SEM analysis and contact angle. Data were submitted to one-way ANOVA and Tukey’s test (α=0.05). Results: At 24h, AE+CA showed the highest value in bond resistance and AF+CF at the lowest, both different from AE+CF while AF+CA was intermediate. After thermocycling, with higher values AE+CA+T and AE+CF-T were similar, as well as AF+CF+T and AF+CA+T with lower values. AE+CF+T and AE+CA+T differed statistically from AF+CF+T and AF+CA+T. Adhesive failure was predominant in all groups with or without thermocycling. At 24h, there was cohesive failures in mixed resin cement in the AE+CA and AF+CF. After thermocycling, there were mixed failures in the AE+CA+T and cohesive failures in resin cement for the AE+CF+T and AF+CA+T. The greater contact angle vas observed in the AE+CF. Conclusions: The association of hydrofluoric acid etching, application of silane with electric current and storage times promoted different values of bond strength, types of failures and contact angles in samples of resin cement bonded to acid-sensitive ceramics. Clinical Relevance: The application of silane with an electric current is a promising method to improve the adhesive bond between resin cement and ceramics, especially when associated with hydrofluoric acid etching.
... This variant of the method, allowed obtaining multiple specimens from a single block, which would provide more consistent results as the testing variance is usually reduced to 10 -25%. 35 Intraorally, bonded indirect ceramic restorations are exposed to complex aging that is associated with changes in temperature, immersion in saliva, occlusal forces and beverages exposure. 36 To simulate intra-oral conditions, In this invitro study, the effect of thermocycling on microtensile bondstrength at ceramic/resin interface was tested. ...
... Pour cette raison, il est recommandé de nettoyer l'intrados de la facette post-attaque AF à l'aide de bain aux ultrasons avec de l'alcool (ou de l'eau distillée) [23] ou par frottement d'acide orthophosphorique [24]. Le silane doit être appliqué en une seule couche et être activé par chaleur [25], le cas échéant, la facette silanisée ne devant pas être manipulée avant une durée minimale de 2 minutes. Sauf recommandation du fabricant en raison de la spécificité du système de colle employé (relyX veneer, 3M), l'application d'une couche de résine adhésive non photopolymérisée dans l'intrados de la facette s'avère totalement optionnelle (pour un meilleur étalement de la résine composite de collage), voire inutile [26]. ...
La facette et le cantilever en céramique collée sont deux thérapeutiques du secteur antérieur qui cristallisent à elles seules l’ensemble du cahier des charges de la dentisterie moderne. Ces deux types de restauration font appel aux techniques adhésives avec un respect maximal du capital tissulaire au service de la biologie et de l’esthétique. La pérennité de la facette ou du cantilever n’est plus à démontrer, de nombreuses publications scientifiques ont ainsi éprouvé leur fiabilité et leur durabilité.
Pour autant, la nature chimique de la céramique employée (vitreuse pour les facettes et majoritairement en zircone pour les cantilevers), la spécificité des conditionnements prothétiques et la topographie des préparations amélaires (vestibulaire ou palatine) imposent un certain nombre de rappels afin d’établir les protocoles idéaux à employer par le praticien.
L’objectif de cet article est d’exposer les protocoles contemporains d’assemblage des restaurations indirectes collées en vitrocéramique et en zircone à travers deux pas à pas illustrés.
... Therefore, they concluded that heat treatment may produce a durable covalent bond. There are different methods for performing the heat treatment of the silane, such as in an oven set at 100°C for 2 min, 33 hot air application at 50 ± 5°C for 15 s, 16 or laser application. 9,24 The parameters of laser application, such as wavelength, frequency, and pulse duration, play a major role. ...
Purpose:
This study investigated the effect of different surface treatments and the effect of silane heat treatment with laser on the shear bond strength (SBS) of a nanoceramic composite to repaired hybrid CAD/CAM blocks.
Materials and methods:
60 hybrid CAD/CAM specimens (Cerasmart, GC) were prepared and randomly divided into six groups according to the different surface treatments (n = 10): group ER: Er:YAG laser+silane (Monobond Plus, Ivoclar Vivadent); group ER+SHT: Er:YAG laser+silane heat treatment; group B: bur+silane; group B+SHT: bur+silane heat treatment; group HF: hydrofluoric acid+silane; group HF+SHT: hydrofluoric acid+silane heat treatment. Afterwards, a universal adhesive (Universal Bond Quick, Kuraray) was applied, and nanoceramic resin composite (Zenit, President) cylinders were bonded to the Cerasmart specimens. They were thermocycled for 10,000 cycles (5-55°C) and subjected to SBS testing using a universal testing machine. Failure modes were examined with a stereomicroscope (15X). Scanning electron microscopy (SEM) was used to evaluate the surface topography (n = 2). The data were statistically analyzed using the Mann-Whitney U-test and the Kruskal-Wallis test (p < 0.05).
Results:
Regarding the surface treatments, group ER showed significantly lower SBS than groups B and HF (p < 0.05). Regarding the presence of silane heat treatment by laser, groups ER+SHT and B+SHT showed significantly lower SBS than group HF+SHT(p < 0.05). In addition, group B+SHT showed significantly lower SBS than did group B (p < 0.05).
Conclusion:
Er:YAG laser treatment for repairing hybrid CAD/CAM blocks was not as effective as bur roughening or hydrofluoric acid etching. Silane heated by Er:YAG laser was incapable of significantly increasing the bond strength to repaired hybrid CAD/CAM blocks.
... Resin cements can determine the success of fixed dental prostheses by bonding juxtaposed surfaces together to achieve marginal sealing and adhesive of interface between different kinds of substrate, as well as adequate preservation and resistance [18]. Generally, two mechanical factors should be considered as for the bonding of ceramics to the tooth: the adhesive forces at the resin-ceramic interface and at the resin-tooth interface [19]. One study showed that the resin cement combined with the ceramic can significantly enhance the micro-shear bond strength [20]. ...
Juxtaposed surfacescould be bond to achieve marginal sealing and adhesive of interfacebetween different kinds of substrate. Therefore, the purpose of the current study is to investigate the bonding strength of threecommon resin adhesives after bonding and polymerization, and to evaluate thebonding effect.PanaviaTM-F resin adhesive, Rely 3M EPSEresin adhesive, and Kerr NX3 resin adhesive were used to prepare modules (10 ×10 × 3 mm3). The glass permeable ceramic was made into a rectangularcomponent (10 × 10 × 10 mm3), ensuring all surfaces to be smooth.Three kinds of different adhesives were bonded to surface of theglass-infiltrated ceramic. Tensile tests, compression tests and shear testswere performed on different adhesives after cold and hot cycles tocomprehensively evaluate the differences in the clinical properties ofadhesives.After testing, the surface hardness of KerrNX3 resin adhesive was the highest among the three, andless affected by water storage. The tensile strength and compressive capacityof Kerr NX3 resin were much stronger than those of the other two adhesives.After cold and hot cycles,Kerr NX3 resin was 39% higher than PanaviaTM-F resin and 15% higher than Rely 3M EPSE resin. Scanning Electron Microscopy(SEM)observations of morphology and failuresurfaces of three adhesives showed that the repairing effect of Kerr NX3 resinwas the best and the bonding strength was the highest. Compared with thePanaviaTM-F and Rely 3M EPSE resin, the bonding strength of Kerr NX3 resin wasthe highest with best repairing effect.
... They bond dissimilar materials together by forming a branched 3D siloxane (-Si-O-Si-) fi lm (i.e. chemical bonding). The stability and effectiveness of this adhesion are also supposed to be improved by heat treatment [11][12][13][14][15][16][17]. Bruzi, et al. [16] based on the evaluation of the shear bond strength of composite resin to CAD/CAM lithium disilicate ceramics recommends a regular application of silane. ...
Recommendations to obtain the best bonding to silica-based ceramics are to prepare its surface by hydrofluoric-acid HF etching and regular application of a silane. This study investigated how the HF-etching followed by ultrasonic water bath cleaning or by an additional phosphoric acid treatment impacts the adhesion properties of a resin (G-CEM LinkForce®) with a lithium disilicate glass-ceramic (IPS Emax Press, Ivoclar Vivadent). Comparison is based on results obtained with HF etching and direct silane application. After HF-etching, a water ultrasonic bath (4 minutes), and a final air drying, the scratch test critical load increases (+ 46%) thanks to chemical bonding. Additional tests are presented including heat treatments (at 85 °C before and after silanization). If HF-etching is followed by phosphoric acid treatment and drying of silane at 85 °C, scratch test critical load increases (+ 42%) due to mechanical bonding. Similar adhesion properties are obtained with two opposite protocols.
... Pairs of composite resin and pretreated ceramic blocks were bonded with dual-polymerized resin cement (RelyX U200 automix; 3M ESPE) under a constant load of 9.8 N. 27 Excess luting agent was removed with foam pellets, and an air blocking gel (Panavia 21 Oxyguard II; Kuraray) was applied around the bonding margin to prevent an oxygen inhibition layer. All the cemented blocks were light polymerized (Elipar S10; 3M ESPE) from 4 sides for 20 seconds ...
Statement of problem
The influence of surface treatments on the bond durability of zirconia-reinforced lithium silicate ceramics (ZLS) is unclear.
Purpose
The purpose of this in vitro study was to evaluate the effect of different surface treatments on the bond durability of zirconia-reinforced lithium silicate ceramic after long-term thermocycling.
Material and methods
Five computer-aided design and computer-aided manufacturing (CAD-CAM) dental ceramic blocks, including 2 zirconia-reinforced lithium silicate ceramic materials (Vita Suprinity/VS and Cetra Duo/CD), 2 commonly used glass-ceramic materials (e.max CAD/EM and Empress CAD/EP), and 1 yttria-stabilized zirconia (Y-TZP, Zenostar/ZS) were tested. Rectangular ceramic blocks were divided into 6 groups and subjected to different surface treatments: group Control (no treatment), group Uni (universal adhesive), group HF (hydrofluoric acid), group CoJet, group HF+Uni (HF and universal adhesive), and group CoJet+Uni (CoJet and universal adhesive). Subsequently, the specimens were cemented to composite resin blocks, sectioned into rectangular microbars of approximately 2×2×12 mm in size, and assigned to 2 groups with and without 100 000 thermal cycles (n=15 per group). The microtensile bond strength (μTBS) test was performed using a universal testing machine. Failure modes were observed with a stereomicroscope and scanning electron microscope (SEM). Three-way analysis of variance (ANOVA) followed by post hoc pairwise comparisons was performed to evaluate the effects of surface treatments, ceramics, and thermocycling on μTBS (α=.05).
Results
The μTBS (MPa) was affected by the surface treatment (P<.001), ceramic type (P<.001), and thermocycling (P<.001). The bond strength after HF etching and universal adhesive treatment was highest in glass-ceramic groups (VS, CD, EP, and EM), while CoJet combined with universal adhesive indicated the highest bond strength in the ZS group before (34.3 ±4.2 MPa) and after thermocycling (16.0 ±2.9 MPa). No significant differences for μTBS were found among ZLS (VS and CD), lithium disilicate ceramic group (EM), and leucite-based ceramic group (EP, P>.05), but they demonstrated better bond strength than zirconia (ZS group, P<.01) after thermocycling. Adhesive failure increased in all groups, and the cohesive failure of glass-ceramic decreased after thermocycling.
Conclusions
ZLS showed similar μTBS with traditional glass-ceramics, including lithium disilicate ceramic and leucite-based ceramic, and more durable bonding than zirconia to resist thermocycling. Moreover, the combination of HF and universal adhesive treatments was the most effective method for ZLS among all the different surface treatments in this study.
... But in real life, this type of coverage is next to impossible [19]. Some studies [39][40][41] have shown that heat treatment on the fibres post silanization could reduce the silane coating thickness, thereby increasing the mechanical properties. However, another study didn't show the improvement in mechanical properties due to heat treatment post the silanization process [42]. ...
Objectives:
This experimental investigation explored the optimisation of silane treatment of surface-modified S-2 Glass fibres in restorative dental composites for improved mechanical performance. The influence of optimum amount of silane to improve the interfacial adhesion at the fibre-matrix interfaces and its effect on the mechanical properties of the restorative composites were explored.
Methods:
S-2 Glass fibres of 5 μm diameter and 250 μm length were surface modified using the acid etching technique. The etched fibres were then treated with either 3-methacryloxypropyltrimethoxysilane (3-MPS), 3-Glycidoxipropyltrimethoxysilane (3-GPS) or 8-methacryloxyoctyltrimethoxysilane (8-MOTS) at varying molar % / wt% concentrations. Fibres that were not silanised with any silane coupling agents were used as the control sample. The silanol content of each mixed silane was observed using Fourier transform infrared (FT-IR) spectroscopy analysis. Fibres (5 wt%) with optimised molar% / wt% silane coupling concentration were added to UDMA/TEGDMA dental resin. Mechanical properties such as flexural strength, flexural modulus, and the breaking energy of the materials were evaluated using a comprehensive experimental programme.
Results:
FTIR spectrum of glass fibre silanised with each silane coupling agent revealed many peaks from 3800 to 1400 cm-1, indicative of -CH3, -CH2, and CO bonding, suggesting the proper silanization of the fibre. The contact angle test revealed that optimum wt% concentration of 3-MPS, 3-GPS and 8-MOTS were 0.5%, 0.8% and 1.4% respectively. The flexural strength of the fibre-reinforced with optimum concentration of 3-MPS (DC-3-MPS_0.5%) increased by 7.0% compared to those of the 2 wt% concentration of 3-MPS fibre-reinforced composite (DC-3-MPS_2.0%). While the flexural strength of optimum concentration 8-MOTS grafted dental resin composites (DC-8-MOTS_1.4%) were 9.9% higher than that of 2 wt% concentration 8-MOTS grafted dental resin composite (DC-8-MOTS_2.0%) and the flexural strength of optimum concentration of 3-GPS (DC-3-GPS_0.8%) was 7.5% higher when compared to that of 2 wt% concentration 3-GPS grafted dental resin composites (DC-3-GPS_2.0%). A concurrent trend was found while investigating the fracture behaviour of the dental composite with optimum wt% concentration of each silane coupling agent against its corresponding higher wt% concentrations. The ANOVA results showed that the optimum fibre-reinforced dental composites grafted with 8-MOTS showed better mechanical behaviour when compared to 3-GPS and 3-MPS.
Significance:
The interfacial adhesion between the fibre and the resin due to silane coupling agents has helped to improve the mechanical properties of the fibre-reinforced dental composite. This is the first experimental study to provide a thorough investigation into the significance of the optimal use of silane coupling agents to treat the S-2 Glass fibres and subsequently the influence on the mechanical performance of the fibre-reinforced flowable dental composites.
... Restoration pre-treatment methods differ according to the material. The recommended method for conditioning the surfaces of ceramic restorations is to treat them with hydrofluoric acid and subsequently apply a silane coupling agent to ensure strong bonding [62][63][64]. For resin-matrix ceramics, chemical etching followed by silane application and alumina air abrasion followed by universal adhesive application are considered to be the best strategies for optimizing the bond strength of PICN material and RBCs under aged conditions, respectively [31]. ...
Objective
To evaluate clinical performance of the new CAD/CAM resin-matrix ceramics and compare it with ceramic partial coverage restorations.
Materials and methods
An electronic search of 3 databases (The National Library of Medicine (MEDLINE/PubMed), Scopus, and the Cochrane Central Register of Controlled Trials) was conducted. English clinical studies published between 2005 and September 2020 that evaluated the clinical performance of CAD/CAM resin-matrix ceramics inlays, onlays, or overlays were selected. The primary clinical question was applied according to PICOS strategy (Population, Intervention, Comparison, Outcome, Study design). The included studies were individually evaluated for risk of bias according to the modified Cochrane Collaboration tool criteria.
Results
A total of 7 studies were included according to the established inclusion and exclusion criteria. From the included studies, 6 were randomized clinical trials while one study was longitudinal observational study without control group. According to the results of the included studies, the success rate of CAD/CAM resin-based composite ranged from 85.7 to 100% whereas the success rate reported for ceramic partial coverage restorations ranged from 93.3 to 100%. Fractures and debondings are found to be the most common cause of restorations failure.
Conclusion
CAD/CAM resin-based composite can be considered a reliable material for partial coverage restorations with clinical performance similar to glass ceramic restorations. However, this result needs to be confirmed in long-term evaluations.
Clinical relevance
CAD/CAM resin-based composites provide a potential alternative to ceramic indirect restorations. However, clinicians must be aware of the lake of knowledge regarding long-term outcome
... It is used in formulations for metal-ceramic restorations to match the thermal contraction of the ceramic to that of the metal upon cooling [24]. Owing to their excellent strength and mechanical properties, leucite ceramics have been widely used in dental porcelains and structural ceramic materials [25][26][27][28][29]. However, to synthesize a pure leucite phase, the process requires extensive heat treatment at temperatures of 1500 • C [30], even with a long sintering period [31], which may have a disadvantage regarding the environmental impact. ...
The aim of this study is to assess the process of synthesizing potassium-based geopolymers (KGL) into leucite ceramics with regard to five variables, namely, alkaline solution ratio (R), sintering time (S), calcining temperature (T), mixing time (M), and curing time (C). Under these conditions, the specimens were tested by the viscosity test, the mechanical properties test, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) to understand the geopolymerization reactions and the characteristics of the KGL network. The results indicate that a KOH to K2O/SiO2 ratio of 1:1 promotes the reaction within metakaolin. XRD analysis of the KGL shows that, when the temperature is 1100 °C, the phase transforms into the leucite phase. Moreover, XRD analysis, mechanical properties, and FTIR all indicate improved characteristics when the curing time increases from 1 to 8 h. This might be attributed to the enhancement of the strong interaction between the matrix and the alkaline solution upon achieving adequate time to complete the geopolymerization process and forming a more stable three-dimensional structure. The formulation which formed the purest leucite phase consisted of: a 1:1 alkaline solution ratio, 10 min mixing time, 8 h curing time, 1200 °C calcining temperature, and 2 h sintering time.
... Cementation of restorations based on lithium disilicate ceramic used in this study is done after etching the inner surface with hydrofluoric acid, which aims to increase the adhesion by infiltrating the adhesive cement in the micro retentions obtained from this action. In addition, the silanization process increases the ceramic-cement adhesion by the connection between the ceramic silica and the organic cement matrix [35]. ...
The purpose of this study is to identify the stress levels that act in inlay and onlay restorations, according to the direction and value of the external force applied. The study was conducted using the Finite Element Method (FEM) of three types of ceramics: pressed lithium disilicate and monolith, zirconia, and three different adhesive systems: self-adhesive, universal, and dual-cure cements. In addition to FEM, the inlay/onlay-dental structure interface analysis was performed by means of Scanning Electron Microscopy (SEM). The geometric models were reconstructed based on computer tomography images of an undamaged molar followed by geometrical procedures of inducing the inlay and onlay reconstructions. The two functional models were then simulated for different orientations of external force and different material properties, according to the considered adhesives and ceramics. The Scanning Electron Microscopy (SEM) was conducted on 30 extracted teeth, divided into three groups according to the adhesive cement type. Both FEM simulation and SEM investigations reveal very good mechanical behavior of the adhesive-dental structure and adhesive-ceramic interfaces for inlay and onlay reconstructions. All results lead to the conclusion that a physiological mastication force applied, regardless of direction, cannot produce a mechanical failure of either inlay or onlay reconstructions. The adhesive bond between the restorations and the dental structure can stabilize the ceramic restorations, resulting in a higher strength to the action of external forces.
... 16 Laser use in dentistry is currently increasing. 24 Previous studies have shown that surface preparation by sandblasting is clinically acceptable and is recommended for bracket bonding on amalgam surfaces. In a similar study by Zaheer et al., the shear bond strength of amalgam samples was reported to be 16.30 ...
Background:
Nowadays, due to the increasing number of adult orthodontic applicants, who also have multiple dental restorations, it is important to have the ability to bond an orthodontic appliance to restoration surfaces.
Objectives:
The aim of this paper was to determine the shear bond strength of ceramic brackets of 3 different base designs bonded to amalgam and composite restorations after using different surface treatment methods in vitro.
Material and methods:
In an in vitro study, the surfaces of 180 amalgam and composite specimens were prepared by using sandblasting and the erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation. Ceramic brackets of 3 base designs, including Star, Cross and Slot, for upper central teeth were bonded to amalgam and composite surfaces by using Transbond™ XT Light Cure Adhesive. All specimens were incubated at a temperature of 37°C for 1 week, and then subjected to shear bond strength tests after 1,000 cycles of thermal cycling. The bond strength of the groups was analyzed by means of the one-way and two-way analysis of variance (ANOVA), and the comparison of the 2 groups was made with Tukey's test. Residual adhesives were also determined by a 4-part criterion (0-3) in different groups and the results were analyzed with the χ2 test.
Results:
There was a significant difference in the shear bond strength of brackets of 3 base designs bonded to amalgam and composite surfaces with different surface treatment.
Conclusions:
According to the results of this study, all surface treatment methods and different bracket base designs were able to provide sufficient shear bond strength on composite and amalgam surfaces. As far as the bracket base design is concerned, the use of each of the 3 base designs in the amalgam group brought desirable results in terms of the adhesive remnant index (ARI) and shear bond strength values; the use of the Star base design in the composite group proved to be suitable.
... Moreover, Naves et al. 6 evaluated the effect of different acid etching times (10,20,40, 60 and 120 seconds) with 10% HF on the adhesion of ceramic, observing that bond strength decreased with increasing etching time. The acid etching causes the precipitation of silica and fluoride salts, 14 which can be trapped in the micro retentions, affecting the bond strength. This seems to be a great problem of acid treatments and the use of agents to remove these residues have been suggested; 15,16 however, other authors have reported that the presence of residues do not significantly reduce the resin bond strength. ...
The objective of this study was to evaluate the influence of hydrofluoric acid (HF) concentration, etching time, and application of phosphoric acid (PA) followed by neutralization with sodium bicarbonate on the bond strength between a feldspar ceramic and resin cement. Thus, 80 blocks (10 x 12 x 2 mm) of glass ceramic (VM - Vita Mark II - Vita Zahnfabrik) were made and randomly assigned to eight groups (n = 10) according to the factors: HF concentration (5 and 10%), etching time (60 and 120 s), and use of phosphoric acid (PA) (with and without). According to the experimental group, 37% PA (Condac, FGM) was applied after HF etching for 60s. Afterwards, samples were immersed in sodium bicarbonate for 1 min then in an ultrasonic bath in distilled water (5 min) for cleaning. After surface bonding treatment, cylinders (Ø = 2 mm; h = 2 mm) of dual resin cement (AllCem / FGM) were made in the center of each block. The samples were then stored in water (37ºC) for 90 days and submitted to the shear bond test (50 KgF, 1 mm/min). Failure analysis was performed by stereomicroscope and scanning electron microscopy. Data (MPa) were analyzed with 3-way ANOVA and Tukey’s test. Only the factor “HF concentration” was significant (p = 0.02). Most failures were of cohesive in ceramic (40%) and mixed types (42.5%). The 10% HF resulted in higher shear bond strength value than the 5% HF. Surface cleaning with phosphoric acid followed by sodium bicarbonate and HF time (60 or 120 seconds) did not influence the resin bond strength to feldspar ceramic.
... The load at failure (N) and the surface area (mm 2 ) for each beam were used to calculate µTBS in MPa. 15,16 Optical microscope (Infinity 2, MEIJI Techno, EMZ-13 TRD, Japan) at 40x magnifications was used to check the debonded specimens. The mode of failure can be categorized as follows: type 1: adhesive failure at the ceramic/ resin interface, cohesive failure in the composite resin (type II) or ceramics (type III) , or mixed failure (type IV). 17 ...
... The acid selectively dissolves the glass matrix creating micromechanical retention, and the silanation serves for the chemical adhesion between the organic and inorganic substances, producing a strong and durable adhesion between the ceramic and the resin cement. 2,3 Regarding zirconia based ceramics several procedures for adhesive cementation have been investigated. Silica-coating through air abrasion associated to application of silane coupling agents has been largely investigated, 4,5,6 and resulted in higher bond strength to composite resins compared to other surface treatments, whether in air, water or after thermocycling. ...
... The application of HF etching plus silane has been recommended to promote chemical bonding between inorganic molecules of the ceramic with organic molecules of these resin cements. 39,40 This sequence is already well established in the literature in terms of bond strength, as these procedures increase the surface energy of the ceramic and the wettability of the resin cement, improving adhesion. 3,31 This greater wettability can be evidenced by the lower contact angle of the treated surfaces, as shown in Figure 2A. ...
Objective
To evaluate the effect of hydrofluoric acid (HF) etching and thermocycling (Tc) on fatigue failure load of feldspathic ceramic restorations cemented with two resin cements.
Methods
Disc-shaped feldspathic ceramic (Vitablocs Mark II; Ø=10 mm, 1.0-mm thick) and G10 epoxy resin (Ø=10 mm, 2.5-mm thick) specimens were made and randomly allocated considering three factors: ceramic etching (ie, with vs without 10% HF plus silane application), resin cement (ie, self-adhesive [RelyX U200; U200] or conventional [Multilink Automix; MA]), and Tc (ie, with vs without 5-55°C/12,000 cycles). Adhesive cementation followed each manufacturer's instructions. The fatigue test (n=20) was based on the staircase approach (250,000 cycles; 20 Hz). Contact angle, surface topography, and fractography analysis were also executed. Specific statistical tests were employed for each outcome (α=0.05).
Results
The interaction of HF and Tc factors decreased the fatigue resistance for both cements (U200 542.63>U200/HF-Tc 495.00; MA 544.47>MA/HF-Tc 506.84). Comparing the cements associated with HF or Tc, there was statistical superiority for MA (U200-Tc 537.37<MA-Tc 561.32; U200/HF 535.79<MA/HF 557.11), and no statistical difference was detected when only cement type or its association with HF-Tc was compared (U200 542.63=MA 544.47; U200/HF-Tc 495.00=MA/HF-Tc 506.84). The fracture always originated from defects at the ceramic-intaglio surface as radial cracks.
Conclusion
HF etching plus silane agent increased the ceramic surface free energy and its wettability, but it did not provide better results in terms of fatigue resistance compared with silane agent application only. The association of HF etching and aging significantly reduced the fatigue resistance of the material, regardless of the resin cement used.
... 1) Micromechanical retention: The Y-TZP surface vitrified by silica coating was etched by hydrofluoric acid to produce strong micromorphological changes such as increased surface roughness and formation of micro-retentive grooves 34,35) . 2) Chemical bonding: Large amounts of Si elements may have improved chemical interactions with silane coupling agents 36) . ...
This study investigated the effects of different silica-based layer coatings on shear bond strength (SBS) between Y-TZP and bovine dentin. Three different silica-based layer coatings were applied to the Y-TZP surface: tribochemical silica coating, vitrification (glaze coating), and composite resin sintering. A silane coupling agent (SIL) was applied to the silica-coated Y-TZP surface in the presence or absence of hydrofluoric acid (HF) treatment. A one-step adhesive was then applied to the silica-coated Y-TZP and cemented to bovine dentin using MDP-free resin cement. The SBS value of the tribochemical silica coating group was lowest among the experimental groups, while the HF+SIL subgroup showed the highest SBS value after vitrification (p<0.05). While hydrofluoric acid etching did not affect the SBS value of the tribochemical silica coating group, it affected the SBS value in the vitrification and composite resin sintering groups (p<0.05).
... Surface ceramics are subjected to varying treatments to increase the surface energy by mechanical or chemical action (Yoshida et al., 2015). Some treatments involving physical action include acid etching (Fabianelli et al., 2010;Kim et al., 2015), airborne-particle abrasion (Ritesh Gourav et al., 2013;Soares et al., 2016), diamond burs, and tribological silica (Neis et al., 2015). Chemical conditioning can be performed using bifunctional silane agents that facilitate the interaction of the AOH groups of ceramics with the ACOOH group of composite resins (Lung and Matinlinna, 2012). ...
Introduction:
Universal adhesives provide the possibility of simplified protocols for using ceramics; however, determining the synergy of these adhesives with silanes and the possibility of replacing silanes requires extensive research.
Objective:
To evaluate the influence of a universal adhesive, associated with airborne-particle abrasion, acid etching, and silane, on the bond strength of a feldspathic ceramic CAD-CAM to composite resin.
Materials and methods:
CAD-CAM feldspathic ceramic blocks were cut into 2-mm slices and were randomly divided into six groups (n = 10): A1, Single Bond Universal (SBU); A2, Adper Single Bond 2 (SB2); B1, silane + SBU; B2, silane + SB2; C1, acid etching + silane + SBU; C2, and acid etching + silane + SB2. Tygon tubes were placed and filled with composite resin. All samples were stored in distilled water at 37 °C for 24 h and then subjected to micro-shear tests. The type of failure was analyzed using a stereomicroscope.
Results:
SBU demonstrated slightly higher adhesion values compared with SB2 in all groups; however, no significant differences were observed between the adhesives (p < 0.05).
Conclusion:
SBU was not statistically superior to the control adhesive. The use of silane prior to a universal adhesive should not yet be eliminated.
... Esta inferencia fue confirmada en este estudio para los brackets metálicos independientemente del termociclado y tratamiento de superficie ( Fig. 1 y Tabla IV). El objetivo del condicionamiento ácido de cerámicas vítreas es promover irregularidades superficiales, a ser impregnadas con la aplicación de silano, y así aumentar la fuerza de unión entre el cemento y la cerámica (Barghi et al., 2000;Kumbuloglu et al., 2005;Taskonak & Sertgöz, 2006;Fabianelli et al., 2010;Fasbinder et al., 2010). ...
To evaluate the shear strength of cemented orthodontic brackets to a dental ceramic based on lithium disilicate. Rectangular samples 80 based glassceramic lithium disilicate were prepared. The samples were initially divided into 4 groups of 20 discs according to surface treatment: 37 % phosphoric acid for 30 seconds (HP); 10 % hydrofluoric acid for 60 seconds (HF); blasting with aluminum oxide for 4 seconds (SB); and diamond-tipped for 10 seconds (DW). Each group was divided into two subgroups for the Edgwise bracket cementation: metallic and ceramic. The two new groups were subdivided into thermocyclers or nonthermocyclics. The thermocycled samples passed 500 cycles with temperature variations between 5 ° C to 55 ° C. The numerical values obtained in the shear test were submitted to descriptive statistical analysis (mean and standard deviation), and the Shapiro-Wilk normality test and nonparametric Kruskal-Wallis and Mann-Whitney tests were performed. It was found that there was no statistically significant difference in the type of surface treatment and conducting or not thermocycling, observing statistically significant difference only on the bracket type, and the bond strength at higher metal bracket than in ceramics. Thus, the type of surface treatment and thermocycling aging were not decisive in the bond strength of orthodontic brackets to the lithium disilicate ceramic.
... Esta inferencia fue confirmada en este estudio para los brackets metálicos independientemente del termociclado y tratamiento de superficie ( Fig. 1 y Tabla IV). El objetivo del condicionamiento ácido de cerámicas vítreas es promover irregularidades superficiales, a ser impregnadas con la aplicación de silano, y así aumentar la fuerza de unión entre el cemento y la cerámica (Barghi et al., 2000;Kumbuloglu et al., 2005;Taskonak & Sertgöz, 2006;Fabianelli et al., 2010;Fasbinder et al., 2010). ...
El objetivo de este trabajo consistió en evaluar la resistencia al cizallamiento de brackets ortodónticos cementados a una cerámica odontológica a base de disilicato de litio. Fueron confeccionadas 80 muestras rectangulares de cerámica vítrea a base de disilicato de litio. Las muestras fueron divididas inicialmente en 4 grupos de 20 discos según el tratamiento de superficie: ácido fosfórico 37 % por 30 segundos (HP); ácido hidrofluorhidro 10 % por 60 segundos (HF); óxido de aluminio durante 4 segundos (SB); y aspersión con punta diamantada durante 10 segundos (DW). Cada grupo fue dividido en dos subgrupos para la cementación de brackets Edgwise: metálico y cerámico. Los dos nuevos grupos fueron subdivididos en termociclados o no termociclados. Las muestras termocicladas pasaron por 500 ciclos con variaciones de temperatura entre 5 °C a 55 °C. Los valores numéricos obtenidos en la prueba de cizallamiento se sometieron al análisis estadístico descriptivo (media y desviación estándar), habiéndose realizado la prueba de normalidad Shapiro-Wilk y las pruebas no paramétricas de Kruskal-Wallis y Mann-Whitney. Se verificó que no hubo diferencia estadísticamente significativa en relación al tipo de tratamiento de superficie y la realización o no de termociclado, observándose diferencia estadísticamente significativa sólo en el tipo de bracket, siendo la resistencia de unión en el bracket metálico mayor que en el de cerámica. Así, el tipo de tratamiento de superficie y el envejecimiento por termociclaje no fueron decisivos en la resistencia de unión de brackets ortodónticos a la cerámica de disilicato de litio.
... restoration durability. Therefore, it was suggested to remove these outermost layers by hot air drying and rinsing with hot water [6][7][8][9][10]. The luting step is followed by the direct application of the resin cement in the inner etched and silanated ceramic surface. ...
Assess the effect of applying a low viscosity resin before placing ceramic restoration with two different luting agent. Twenty slices from IPS e.max CAD (Ivoclar Vivadent) were fired and assigned to 5 treatment surface groups; E: hydrofluoric acid (HF); E/S: HF-etching + silane (20 s); E/S+: HF-etching + silane (60 s); S: silane (20 s); S+: silane (60 s). Before building the cylinder with regular or flowable composite resin for the SBS test, half of each treatment surface group received adhesive (Optibond FL bottle #2), and the other half no adhesive. The SBS test was performed after 24 h. Statistical analysis was performed using multifactorial analyses of variance Two-way ANOVA. The Tukey HSD test was used to test the average values of all groups. The significance level adopted in all analyses was ≤ 0.05 (p < 0.05). Groups E/S and E/S+, with flowable + adhesive and E/S with regular composite resin + adhesive, showed the highest SBS values (22.05, 18.91 and 21.06 MPa respectively), followed by group E with or without adhesive, for both luting agent. The lowest bond strength was observed when the silane was applied alone, independent of the adhesive coat and luting agent (0.65–5.55 MPa). When the adhesive was omitted, flowable presented high bond strength compared to composite resin in groups ES and ES+. The low viscosity resin in the etched and silanized ceramic surface is important to obtain high SBS values.
El bullying o acoso escolar es una forma de hostigamiento constante, en el cual existe la intencionalidad de causar daño a otra persona y que evidencia un desbalance de poder entre víctima y victimario; en tanto que, el cyberbullying o ciberacoso es muy similar, aunque con la particularidad de que incluye la utilización de nuevas tecnologías y redes sociales para descalificar, humillar y acosar a otros estudiantes. El presente artículo tiene como objetivos: describir las consecuencias que se derivan del bullying y cyberbullying entre adolescentes y examinar las propuestas de intervención psicoterapéutica más referidas frente a tales formas de acoso. Se realizó una revisión sistemática de la bibliografía de los últimos 5 años (2018-2023), empleando las bases de datos: Scopus, Web of Science, Pubmed y Lilac y Google Scholar; en la selección de la información se empleó el método PRISMA obteniéndose 32 artículos con los que se desarrolló esa investigación. Se obtuvo como resultado que las consecuencias del bullying y cyberbullying son: depresión, trastorno de estrés postraumático, ideación y riesgo suicida, baja autoestima, conductas autolesivas, consumo o dependencia de alcohol y estupefacientes, quejas somáticas y bajo rendimiento académico. A su vez, se constató que son 2 los modelos psicoterapéuticos mayormente referidos: la Terapia Cognitiva Conductual y la Terapia Racional Emotiva Conductual. Ambas ayudan significativamente en la reducción de la victimización física y verbal, depresión, ansiedad, ideación suicida y conductas autolesivas de los adolescentes acosados.
Amaç: Diş hekimliğinde hastaya uygulanan restorasyonların hasta ağzında uzun süre düşmeden kalması restorasyonun başarısı açısından önemli kriterler arasında yer almaktadır. Bu sebeple çalışmamızın amacı güncel fırınlama işlemine gerek kalmadan hekim tarafından da masa başı parlatılabilen güncel CAD/CAM bloklarına uygulanan farklı yüzey işlemlerinin rezin siman ile olan bağlantısının incelenmesidir. Gereç ve Yöntem: Vita Enamic ve Lava Ultimate bloklar hassas kesme cihazı, PEEK disk ise CAD/CAM cihazı ile 2 mm kalınlığında ve her bloktan kontrol, HF asit, 50 µm Al2O3 tozu, 30 µm Silika kaplı Al2O3 tozu uygulamaları olmak üzere 15’er adet (n=15) üretildi. Rezin siman uygulanan örnekler termal devirlendirme ile yaşlandırma işlemi uygulandı. Sonrasında örneklere instron cihazı ile kırma testi uygulandı. Bağlantı sonuçları istatistik programında değerlendirildi. Bulgular: Elde edilen bulgular incelendiği zaman uygulanan tüm yüzey işlemlerinin bağlantı değerlerini arttırdığı ve tüm gruplardaki en yüksek bağlantı değerinin silika kaplı Al2O3 tozu uygulanan gurupta (VSi 17.2750±1.89167; LSi 18.0815±1.66664; PSi 14.8151±1.57730) görüldü. Lava Ultimate ve Vita Emamic gruplarına uygulanan HF asit’in bağlantı değerlerinin istatiksel olarak PEEK’e uygulanan HF asit grubundan yüksek olduğu görüldü (p˂0.05). Sonuç: Çalışmamız sonucunda CAD/CAM bloklarına uygulanan tüm yüzey işlemlerinin bağlantı değerlerini arttırdığı bunun yanında silika kaplı Al2O3 tozu ile kumlama işleminin en başarılı sonuçları verdiği gözlemlenmiştir.
This study investigates fracture resistance of adhesive ceramic overlays of various designs. Forty-eight upper premolar teeth were divided into eight groups. The variations were: shoulder margins on the buccal and lingual surfaces with axial wall heights of 1, 2, or 3 mm; one shoulder margin with axial wall height of 1, 2, or 3 mm on the lingual surface and one contrabevel margin on the buccal surface; contrabevel margins on the buccal and lingual surfaces; and a control of sound teeth. Overlays were designed and fabricated with CAD/CAM using zirconia-reinforced lithium disilicate ceramic and bonded with resin cement. Samples underwent thermocycling and dynamic fatigue equivalent to 6 months of use. Compressive loading was applied until fracture, and fracture mode was analyzed. Results showed no statistical difference in fracture resistance between designs, and the fracture pattern of most was involvement of pulp tissue and below the CEJ. Fracture resistance of the restored teeth was also not statistically different from the control. All control fractures were within the dentin and above the CEJ. Overlay restorations were therefore effective in strengthening damaged teeth and imparting fracture resistance equal to sound teeth, and axial wall heights and margin types did not influence this result.
Introduction
Neurosensory disorders may be considered as a complication from surgical procedures, such as dental implants and mandibular osteotomy [1–3 Akal ÜK, Sayan NB, Aydoǧan S, et al. Evaluation of the neurosensory deficiencies of oral and maxillofacial region following surgery. Int J Oral Maxillofac Surg. 2000;29(5):331–336.
Steinberg MJ, Kelly PD. Implant-related nerve Injuries. Dent Clin NA. 2015;59(2):357–373.
Al-Sabbagh M, Okeson JP, Bertoli E, et al. Persistent pain and neurosensory disturbance after dental implant surgery: prevention and treatment. Dent Clin North Am. 2015;59(1):143–156. ]. In these cases, the orofacial damage can involve general and professional patient impairments. Low-level laser therapy (LLLT) has been reported to be effective in reducing neurosensory recovery time, while promoting nerve regeneration [4 Bittencourt MAV, Paranhos LR, Martins-Filho PRS. Low-level laser therapy for treatment of neurosensory disorders after orthognathic surgery: a systematic review of randomized clinical trials. Med Oral. 2017;22(6):e780–e787. [Google Scholar],5 Mohammed IFR, Al-Mustawfi N, Kaka LN. Promotion of regenerative processes in injured peripheral nerve induced by low-level laser therapy. Photomed Laser Surg. 2007;25(2):107–111.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]]. This study aimed to analyse the LLLT impact on postsurgical neurosensory recovery, namely for dental and maxillofacial surgery patients.
Materials and methods
Patients previously submitted to dental and/or maxilofacial rehabilitation at Centro Hospitalar Universitário de Coimbra/Faculty of Medicine, University of Coimbra, were selected. Anamnesis, examination and neurosensory evaluation were performed to determine the presence and location of neurosensory disorder. The elected orofacial area was irradiated using a continuous wave diode laser at 660 nm (SIROLaser Blue; Sirona, Bensheim, Germany) in two sessions per week, until satisfactory results were achieved. The measure of health-related quality of life was performed by EQ-5D-5L questionnaire, before and after the LLLT treatment. This study was approved by the ethics committee of Faculty of Medicine of the University of Coimbra and the informed consent document was performed.
Results
Two patients (both Female, Age 22) were selected. Treatment lasted approximately 1 months in both cases. The mean score before and after treatment (0–100 scale), of the EQ-5D-5L questionnaire was 70.0–95.5.The recovery of the neurosensory disorder allowed the quality improvement in all 5 dimensions: mobility, self-care, daily activities, pain/discomfort and anxiety/depression. No reactions or side-effects were reported.
Discussion and conclusions
5 dimensions of health quality were analysed and the severity level degrees were related with the corporal/patient impairment. The results supported the use of LLLT as an effective treatment option by accelerating the recovery of postsurgical neurosensory disturbances, improving the patient’s health.
Aim
To assess the push-out bond strength (PBS) of glass fiber post (GFP) conditioned using different surface treatment regimens bonded to radicular dentin
Material and Methods
Sixty central incisors and canine were collected and disinfected. Decoronation following working length was determined using K-file. Rotary file system was used for cleaning and shaping. Canals of all samples were dried with paper points and obturated with gutta percha. Canal space was prepared with peso reamers. Now samples were randomly allocated into six groups based on pretreatment of GFP. Post in group 1 treated with 9% HFA+ Silane, post in group 2 surface treated with silane only, Post in group 3 surface treated with airborne particle (50µm), group 4 post conditioned with photodynamic therapy (PDT), group 5 post pretreatment was performed with MBP and in group 6 GFP was not treated. Conditioned and non-conditioned posts were positioned in canal space and cemented. Each tooth was sectioned coronally, middle and apically. All sections were positioned in universal testing machine (UTM) and debonded surfaces were evaluated for failure modes. The means and standard deviations of PBS were examined using one-way analysis of variance (ANOVA). The means of PBS were compared using Tukey multiple comparison tests with a significance threshold of (p< 0.05).
Results
Coronal third of group 3 in which posts were sandblasted using airborne Al2O3 particle presented the highest PBS (11.21±0.64 MPa). Whereas, an apical section of group 4 in which posts were treated with PDT exhibited the lowest bond integrity.
Conclusion
Sandblasting using airborne particles (50µm) and hydrogen peroxide (H3PO4) conditioned with GFP exhibited significantly higher bond strength as compared to the control. However, PDT decreases the PBS of fiber post with the root dentin.
Objective
Recommendations to obtain the best bonding to silica-based ceramics are to prepare its surface by hydrofluoric-acid HF etching and regular application of a silane. This study investigated how the HF-etching following by ultrasonic water bath cleaning (recommended protocol to improve the bonding with a composite resin), modifies the surface chemistry of a lithium disilicate glass-ceramic and impacts the chemical bonding with silane.
Methods
Lithium disilicate glass-ceramic discs (IPS Emax Press, Ivoclar Vivadent) were mirror polished, etched with 9% HF for 20 s and rinsed 1 min under water. Two post-etching cleaning were compared: (1) no additional cleaning and (2) immersion in water ultrasonic bath for 4 min. Morphology evolution of the surfaces was carried out by scanning electron microscopy. Chemical changes were studied using X-ray Photoelectron Spectroscopy and Nano Auger Electron Spectroscopy analyses. Identification of the compounds formed with fluorine was based on by High Resolution Transmission Tlectronic Microscopy .
Results
Residues left on the surface of the discs after etching, the fluorine salts, were eliminated after the ultrasonic bath cleaning. However, analyses showed presence of fluorine on the lithium disilicate needles associated among others with the lithium. HR-TEM validates the presence of Li2SiF6 crystallized phased. A mechanism to explain silane bonding when Li2SiF6 phase is formed on the Li2Si2O5 needles, is proposed.
Significance
HF-etching leads to the formation of lithium and fluorine contain LiSi2F6 nano-precipitates on the Li2Si2O5 needles which helps to improve the bonding with silane.
Enhance the bonding of cement to ceramic surface with a variety of ceramic surface modifications have been established. Air-abrasion using alumina particles, hydrofluoric acid has been shown to provide micromechanical interlocking at the ceramic-resin interface. The aim of the present study was to evaluate the effect of two surface treatments; acid etching and sandblasting; on the shear bond strength of cemented newly introduced zirconia-reinforced lithium silicate ceramics following thermocycling. Methods: 24 discs of Zirconia- reinforced glass ceramics (Celtra Duo) were tested using 10% hydrofluoric acid for 20 s (control group) and 50 µm aluminum oxide for 60 s at 10 mm distance from the nozzle tip of sandblasting machine. Subsequent to the surface treatments, both groups were salinized and cemented to composites background discs using self-adhesive dual cure resin cement (BisCem). All sample were subjected to 2500 thermal cycle shear bond strength and failure mode was evaluated. The results of the t-test indicated that the bond strength value is significantly influenced by the surface treatment method. It was found that hydrofluoric acid group recorded statistically significantly higher shear bond strength mean value (10.81 MPa) than aluminum oxide sandblasting group (7.76 MPa) as indicated by t-test (t = 2.9, p = 0.0109 < 0.05). Conclusion: failure mode showed a relation between the bond strength and the failure type mixed failure showed with higher bond valves and cohesive failure accompanied with lowest bond strengthen values. The shear bond strength of zirconia reinforced lithium silicate (Celtra Duo) ceramic cemented to resin cement was affected by the type of surface treatment.
In this study, the effect of saliva contamination and cleaning procedures on the bond strength of lithium disilicate (LS2) ceramics was investigated at different timings of silane treatment. Micro-tensile bond strength (μTBS) test using a universal testing machine was performed (n = 24). For analysis of adhesive surface characteristics, water contact angle was measured (n = 3). After saliva contamination, the salivary protein level using the Bradford assay was quantified (n = 3). The pre-conditioned surfaces were observed using a field emission-scanning electron microscope (FE-SEM). Saliva contamination and the silane treatment timing significantly affected the μTBS of LS2 ceramics (p < 0.05). However, cleaning methods did not show any significant differences in μTBS (p > 0.05). Water contact angle increased after silane treatment. High concentration of salivary protein was detected in the group where saliva contamination occurred before silane treatment (p < 0.05). FE-SEM analysis showed that the etched surfaces of the contaminated LS2 specimens were covered with oral bacteria and other salivary components. It also showed that ultrasonic cleaning was effective in eliminating salivary contaminants while air-water spray was not. Saliva contamination of the surface of LS2 ceramics deteriorates μTBS. To minimize the effect of saliva contamination, prompt silane treatment to etched surface of LS2 ceramic is recommended.
Since the mode of failure of resin composites bonded to ceramics has frequently been reported to be cohesive fracture of either ceramic or resin composite rather than separation at the adhesive interface, this study was designed to question the validity of shear bond strength tests. The reasons for such a failure mode are identified and an alternative tensile bond strength test evaluated. Three configurations (A, conventional; B, reversed; and C, all composite) of the cylinder-on-disc design were produced for shear bond strength testing. Two-dimensional finite element stress analysis (FEA) was carried out to determine qualitatively the stress distribution for the three configurations. A tensile bond strength test was designed and used to evaluate two ceramic repair systems, one using hydrofluoric acid (HF) and the other acidulated phosphate fluoride (APF). Results from the shear bond strength tests and FEA showed that this particular test has as its inherent feature the measurement of the strength of the base material rather than the strength of the adhesive interface. In the tensile test, failure invariably occurred in the adhesive layer, with HF and APF showing a similar ability to improve the bond of resin composite to ceramic. It is concluded that the tensile bond strength test is more appropriate for evaluating the adhesive capabilities of resin composites to ceramics.
During the past few years, the interest in using ceramic inlays and veneers has increased. New materials and methods have been introduced to bond these restorations to resinous materials. Since our knowledge of how to optimize such bonding is limited, the objective of this study was to test the hypothesis that various surface treatment variables and combinations of these variables affect the strength of the ceramic/composite interphase of ceramic inlays differently. The influences of material composition, surface-roughening method, silane treatment, silane heat treatment, and storage condition on bond strength were investigated. Three ceramics (Dicor, Mirage, Vitabloc), three surface-roughening methods (etching, sandblasting, grinding), three silane treatments (gamma-methacryloxypropyltrimethoxysilane [MPS], MPS+paratoluidine, vinyltrichlorosilane), two heat treatments (20 degrees C for 60 s, 100 degrees C for 60 s), and two storage conditions (24-hour dry, one yr in water at 37 degrees C) were studied. For each of the 108 combinations, five specimens were tested. Ceramic cylinders were treated according to group assignment and bonded to blocks of the same ceramic material with a dual-cured resin. The shear bond strength was determined, and the experimental factors were evaluated by analysis of variance. The results showed that surface-roughening method had the strongest effect on bond strength, while ceramic selection had the least significant effect. Of the surface-roughening methods, etching was associated with higher bond strength values than either sandblasting or grinding.(ABSTRACT TRUNCATED AT 250 WORDS)
Sixty-six class-II CAD/CAM-manufactured ceramic inlays (Cerec) were placed in 27 patients. Each patient received at least one inlay luted with a dual-cured resin composite and one inlay luted with a chemically cured resin composite. The inlays were examined 5 years after luting using the California Dental Association (CDA) criteria. Eighty-nine percent of the 66 inlays were rated 'satisfactory'. During the follow-up period replacement was required for 3 inlays because of inlay fractures (4.5%) and 1 inlay because of fracture of the tooth substance (1.5%). All those inlays were luted with the dual-cured resin composite luting agent. Of the remaining 62 inlays the CDA rating 'excellent' was given to 84% for color, 97% for surface, and 81% for anatomic form. 'Excellent' margin integrity was seen in 52% of the dual-cured resin composite luted inlays and in 61% of the chemically cured resin composite luted inlays. No statistically significant (P> 0.05) difference was observed between the two luting agents.
The purpose of this review is to describe all of the various modifications of the microtensile bond test in one paper, so that investigators can select the modification that best suits their needs.
The essence of the microtensile test is the division of resin-bonded teeth into slabs between 0.5 and 1.0 mm thick that are then trimmed in such a manner that tensile force will be concentrated on the bonded interface during testing. Among the many advantages of the technique are that each tooth produces multiple specimens. Further, there is no need for a matrix to limit the bonded surface area, since the area is determined by the dimensions of the trimmed specimens.
The various modifications of the microtensile test have been used to measure differences in regional bond strength across occlusal dentin, down the external surface of teeth from crown through roots, down the internal surface of root canals from cervical to apical thirds, as well as to compare normal vs caries-affected occlusal dentin and normal vs sclerotic cervical dentin. The technique is ideal for evaluating the long-term durability of resin-hard-tissue bonds.
The microtensile test methods offer versatility that cannot be achieved by conventional methods. It is more labor-intensive than conventional testing, but holds great potential for providing insight into the strength of adhesion of restorative materials to clinically relevant sites and substrates.
The purpose of the present study was to conduct a systematic review of ceramic inlays, assess the quality of published clinical studies, and determine the clinical effectiveness of ceramic inlays compared to other forms of posterior restorations. Prospective clinical trials of ceramic inlays published from 1990 to 2001 were retrieved by electronic and hand searching. The methodological quality of each study was assessed by two calibrated reviewers using a standardised checklist. The clinical effectiveness of ceramic inlays was evaluated in terms of failure rate, postoperative pain, and aesthetics. The results were compared to those of other forms of posterior restorations by means of an odds ratio. Among 46 articles selected for quality assessment, only five (10.6%) reported randomised controlled trials and 15 (32.6%) presented controlled clinical trials. The remaining 26 papers (56.5%) were longitudinal clinical trials lacking control groups. Only three papers fulfilled the requirement for statistical analysis to evaluate the clinical effectiveness of ceramic inlays. The results indicate no significant differences in longevity or postoperative sensitivity between ceramic and other posterior restorations over assessment periods of up to 1 year. It is concluded that no strong evidence is available to confirm the clinical effectiveness of ceramic inlays in comparison to other posterior restorations. Greater attention is required to the design and reporting of studies to improve the quality of clinical trials of ceramic inlays.
This overview presents a description of organofunctional trialkoxysilane coupling agents (silanes), their chemistry, properties, use, and some of the main clinical experiences in dentistry.
The main emphasis was on major dental journals that have been reviewed from 1958 up to the latest research news from 2002. A MEDLINE search with the key words "dental silanes" was used. Special silane literature and journals outside dentistry were also cited.
The main emphasis is on the use of silanes in prosthetic and restorative dentistry. Clinical relevance was based mainly on either short- or long-term tests. The interpretation of various results is not given, mainly because of controversial observations that may be very difficult to explain. Nevertheless, the majority of the clinical results pointed to silanes playing a significant role in the adhesion process. Silane reaction mechanisms were not entirely understood, and there exist several theories for bonding mechanisms for silanes and substrates.
Dental materials offer a continuously challenging forum for silanes, and silanes will play an essential role in material development.
Statement of problem. The temperature reported for thermally treating silanated ceramics to improve composite-ceramic bonding is often too high for chairside applications. Purpose. This study investigated whether post-silanization drying with a stream of warm air could enhance the composite/ceramic tensile bond. Material and methods. Thirty-two ceramic blocks (6 x 6 x 9 mm), 16 of each ceramic, were fabricated and divided into 8 subgroups using 4 roughening procedures and 2 silanization protocols per ceramic (Eris and IPS Empress). Roughening included polishing to 1200 grit as control (P), airborne-particle abrasion (A), hydrofluoric acid etching (E), or a combination of abrasion and etching (AE). Silanated surfaces were dried with room-temperature air (SR) or 45 +/- 5degreesC warm air (SH). An adhesive (Heliobond) was applied and light-polymerized before adding composite (Tetric Ceram). Thirty-three specimens (0.9 x 0.9 x 18 mm) were cut from a pair of blocks and stored in 37degreesC distilled-water for 3 weeks. Each specimen was loaded under tension until failure in a universal testing machine (n = 33). Strength (MPa) was calculated by dividing the failure load by the cross-sectional area. Mode of failure was investigated with scanning electron microscopy (SEM). Statistical analyses were performed with ANOVA and the Tukey HSD test (alpha = .05). Results. The mean tensile bond strength values (SD) in MPa for P, A, E, and AE procedures were, respectively, 11.4 (5.4), 11.9 (5.4), 9.9 (2.6), and 15.8 (4.3) for Eris/SR; 17.8 (6.2), 20.4 (7.1), 18.0 (6.7), and 18.8 (3.9) for Eris/SH; 9.3 (2.8), 14.0 (4.0) 17.1 (3.7), and 23.2 (6.8) for IPS-Empress/SP, and 14.8 (4.5) 22.6 (4.8), 22.7 (5.0), and 28.7 (4.4) for IPS Empress/SH. ANOVA indicated the influence of ceramic material, roughening, and postsilanization drying was significant (P < .0001). The Tukey HSD test showed mean strength values higher for IPS Empress than for Eris, SH greater than SR, and AE producing the highest mean strength values. SEM examination showed there were greater areas of cohesive failure with SH specimens. Conclusion. Silane drying by a stream of warm air was effective in enhancing tensile bond strength of composite to ceramic.
A luting agent for fixing indirect dental restorations has to be a sophisticated material as, apart from being biocompatible, it must allow complete seating, provide mechanical support, has to secure the retention and to seal the gap between restoration and tooth structure for many years of function in an aggressive bio-chemical and mechanical environment. Because of their adhesive potential, the latest generations of dental cements, the glass-ionomer and resin-based composites offer improved results. However, a major disadvantage of both classes of materials is their setting, being accompanied by shrinkage, which eventually leads to fracturing of the brittle ceramic. Apparently conflicting interests like being at the same time flexible as well as rigid, hold for luting cements for full ceramic restorations. The interaction between layer thickness, curing shrinkage stress, visco-elasticity, module and strength for a thin adhesive cement layer will be discussed in the perspective of durable functioning of ceramic restorations.
The objective of this study was to determine the effect of selected surface treatments on the surface texture of a feldspathic porcelain. The three different etchant treatments were, acidulated phosphate fluoride (APF) applied for 10 min and hydrofluoric acid (HF) applied for 1 and 4 min. After acid treatment, half of the specimens from each group were cleansed with water and others were subjected to ultrasonic cleaning and then dried. Half of the specimens cleansed with two different methods were treated with silane. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the effects of such treatments. Etching with APF displays shallow patterns. Etching for 1 min with HF displays deep channels, pores and precipitates on the surface and as the etching time increased these channels were replaced by larger channels. EDS analyses show that the crystalline precipitates on the etched surfaces, which were not readily soluble in water, were the reaction products of Na, K, Ca, Al, etc. HF displayed a more roughened surface than the APF gel. However, the precipitates remain on the surface after acid application, they can only be removed by ultrasonic cleaning and cannot be removed by rinsing.
The availability of improved ceramic materials, bonding techniques, new technology and issues of amalgam safety have led to a revival of interest in ceramic inlays in density over the past ten years. Clinical studies have been carried out during this time using various evaluation technique to assess the clinical performance of these restorations.
In this paper, recent clinical studies are examined and a review of the current state of knowledge regarding the clinical performance and survival statistics of ceramic inlays in presented. The major problems associated with ceramic inlay therapy appear to be fracture, hepersensitivity, degree of fit, maintenance of marginal integrity, microleakage, bond failure and cement wear. Other areas which also effect the clinical performance of ceramic inlays are ceramic wear, opposing tooth wear, plaque accumulation, gingivitis, secondary caries, colour stability, anatomic form and radiopacity.
Recommendations based on the findings of clinical studies are also preseneted and whilst no specific material or technique has been shown to be clearly superior, certain principles which predispose to success can be identified.
When compared with other forms of aesthetic intra-coronal restorations, ceramic inlays perform well. However, their high cost and extreme technique sensitivity would appear to restrict their use to certain limited clinical situations.
Hydrofluoric acid is a toxic substance used widely in both industrial and domestic settings. It can cause severe burns, as well as systemic toxicity. Death has been reported from as little as 2.5% body surface area (BSA) burn involving concentrated acid. Topical and parenteral calcium salts have proven effective therapy for both dermal and systemic manifestations. All emergency physicians should be aware of the unique complications and treatment of these injuries.
Three etchants (Super Etch, Stripit, and Acidulated Phosphate Fluoride Gel) were evaluated for their ability to create micromechanical retentive areas in three commercial porcelains (Ceramco II, Mirage, and Vita).
The flexural strengths of porcelain bonded to composite resin specimens using four organosilane materials were compared. Eighty hand-condensed Vita porcelain specimens were stored in distilled water or ambient humidity before sectioning. Three groups (n = 30) of hydrated specimens were repaired to their original dimensions by using Silux composite resin with Kerr Ultrafine Porcelain Repair Bonding system, 3M Porcelain Kit with ScotchPrimer, or Fusion materials. A fourth group (n = 30) of hydrated specimens was repaired with the DenMat Ultrabond Restorative kit. Four groups (n = 10) of unhydrated specimens were repaired the same as the hydrated specimens. Fracture occurred at the porcelain-to-composite resin interface with three-point loading on the repair interface at 3 x 10(2) mm/min. No difference between Kerr, 3M, and Fusion products, when used with Silux composite resin, was found. The DenMat product had lower strengths. The unhydrated specimens had significantly higher bond strengths than the hydrated specimens with all products.
The lack of consistent values for dentine bond strengths in shear or in tension from what are superficially identical experimental procedures has led to ambiguities in the interpretation of the data. These variations in bond strength are usually considered to be related to different adhesive procedures. However so far little attention has been paid to the detail of the test procedures used. In this study the sensitivity of bond strengths to changes in testing conditions has been calculated using finite element stress analysis. It is shown that tensile and shear bond strengths are highly dependent on the geometry of the test arrangement and the materials involved. It is concluded that the concept of 'average stress' for the measurement of bond strength does not stand up to close examination. The measurement does not provide a material property as its value is dependent on local conditions and the actual stresses have little relationship to the average stress value. This demonstrates that there is a need for the standardization of test procedures for the measurement of bond strengths so that a universally valid comparison between different bonding agents can be performed.
This study evaluated the adhesion of composite resin to five different surface conditions of porcelain samples that were treated with three kinds of silane agents. Two of these were commercially available Porcelain Liner M and Tokuso Ceramic Primer, and one was an experimental agent. The commercially available silane agents gave high bond strengths without hydrofluoric acid etching, which gave the greatest roughness on the porcelain surface. One component of these commercially available silane agents was gamma-methacryloxypropyl trimethoxysilane, and the other was the carboxylic acid. As a result of the effective formation of siloxane bonds by mixing with acid solution, porcelain surface conditions did not affect the bond strengths.
The purpose of this study was to test the null hypothesis that there is no relationship between the bonded surface area of dentin and the tensile strength of adhesive materials.
The enamel was removed from the occlusal surface of extracted human third molars, and the entire flat surface was covered with resin composite bonded to the dentin to form a flat resin composite crown. Twenty-four hours later, the bonded specimens were sectioned parallel to the long axis of the tooth into 10-20 thin sections whose upper part was composed of resin composite with the lower half being dentin. These small sections were trimmed using a high speed diamond bur into an hourglass shape with the narrowest portion at the bonded interface. Surface area was varied by altering the specimen thickness and width. Tensile bond strength was measured using custom-made grips in a universal testing machine.
Tensile bond strength was inversely related to bonded surface area. At surface areas below 0.4 mm2, the tensile bond strengths were about 55 MPa for Clearfil Liner Bond 2 (Kuraray Co., Ltd.), 38 MPa for Scotchbond MP (3M Dental Products), and 20 MPa for Vitremer (3M Dental Products). At these small surface areas all of the bond failures were adhesive in nature.
This new method permits measurement of high bond strengths without cohesive failure of dentin. It also permits multiple measurements to be made within a single tooth.
Three commercially available dental silane primers, two single-phase prehydrolyzed and one two-component system were investigated for their composition, extent of hydrolysis, surface interactions, bond strength and interfacial topography when used on three representative porcelain alloys (Au-Pd, high-Pd, Ni-Cr). Five tests, 1H FT-NMR, FTIR, GPC, ESCA and EPMA, were used to determine the composition and the surface interaction profiles. Shear tests were performed to assess the bond strength values. According to the results, all the primers contain gamma-methacryloxypropyltrimethoxysilane (gamma-MPTS) at concentrations of 1.15-18.86 g/100 mL, two in ethanol and one in isopropanol. Traces of acetic acid were found in the prehydrolyzed primers. All the primers demonstrated partial hydrolysis of the methoxy groups. Prehydrolyzed primers exhibited a higher rate of hydrolysis and better orientation of hydrolyzed methoxy groups towards the Ni-Cr alloy surface. Due to the extent of surface oxidation, the Ni-Cr alloy provided more bonding sites for silanols than the other two types of alloys. The Ni-Cr alloy demonstrated the highest shear bond strength values on smooth surfaces regardless of the type of primer used. The results of the present study suggest that active prepolymerized primers may provide significant advantages over two-component systems in the repair of Ni-Cr porcelain fractures involving removal of the metal oxide layer.
A review of current clinical research has demonstrated that successful attachment with resin-based bonding systems is achieved through brief acidic conditions of dentin, followed by thorough coverage with resin priming and bonding agents. This article discusses factors of clinical relevance in achieving optimal results. Effective priming, using multiple coats to enhance resin penetration to the full depth of dentinal demineralization, is crucial. A thin, uniform layer of bonding resin is a critical, elastic intermediary for absorbing stresses of polymerization shrinkage. An air stream should be used only for evaporation of solvent and not for spreading bonding resin, because use of an air stream causes uneven thinning of this valuable intermediate layer. Contamination of the dentinal surface with excessive moisture or solvent or the presence of air voids will make bonding unpredictable under clinical conditions. Adequate etching of peripheral enamel continues to be an important factor in the long-term retention of adhesive restorations.
Porcelain restorations are widely used in restorative dentistry with general success. On occasion however, fracture of the porcelain occurs. Sometimes a repair may be attempted using resin composite and one of the many bonding systems available. This in vitro investigation sought to determine and compare the shear bond strengths between a visible light-cured resin composite (Prisma TPH) and dental porcelain (Matchmaker Porcelain) for three different bonding systems (Scotchbond Multipurpose Plus (SMP); One-Step (OS); DenTASTIC (D)) with a view to conducting a larger study to assist in material selection. All measurements were performed one week following the preparation and storage of specimens in distilled water, at 37 degrees C, using a Universal Testing Machine at a crosshead speed of 0.5 mm/min. Although the mean shear bond strengths differed significantly (P < 0.05) (OS > SMP) and the Weibull modulus value of SMP was significantly (P < 0.05) lower than both OS and D the almost exclusive cohesive mode of failure observed, within the porcelain itself, suggested that the test was more a reflection of the quality of the underlying porcelain than the union under investigation. It was thus concluded that the shear bond strength test employed here, and in other studies did not truly reflect the shear bond strength at the porcelain/composite interface and that a more meaningful test should be developed. The observed cohesive failure may account for repeated clinical failures of porcelain repairs where bonding to an inherently flawed porcelain structure inevitably results in further failure.
In a previous article the authors examined the evolution of the bond strengths of 2 dental feldspathic ceramics. The objective of the present study was to evaluate the effect of surface modifications with hydrofluoric acid gel (concentration 10%) on the surface energy of 2 dental feldspathic ceramics (GC and PVS).
For an energy characterization, 30 samples of GC and 30 samples of PVS were built. This study comprised the measurement of contact angles to determine the work of adhesion (WA) of the 2 ceramics. The evolution of the work of adhesion depended on the action of the hydrofluoric acid gel on the roughness of the surface of the 2 ceramics.
In a polished state PVS presented a higher work of adhesion than GC. Etching the ceramics with hydrofluoric acid gel increased the work of adhesion, especially for GC, but this treatment was not sufficient to obtain a high work of adhesion.
Etching with hydrofluoric acid gel was not sufficient to raise the work of adhesion of the 2 ceramics. Silanization is preferable to etching.
The behavior of dual-cure cements over time remains unclear. This study evaluated the extrusion shear strength of the bond between feldsphatic porcelain and bovine dentin at different time intervals, using three adhesive systems based on dual-cure cements and one based on a self-cure cement.
The adhesive systems evaluated included: C&B/One-Step, Enforce/Prime&Bond NT Dual-Cure, RelyX ARC/Single Bond and Variolink II/Syntac SC. Discs of bovine root dentin, 2.5 mm thick, had the root canal prepared with a standardized taper. Porcelain truncated cones etched with 4% hydrofluoric acid and silanized were bonded into the perforations. The extrusion shear test was performed after 15 min, 4 h, 12 h, 24 h, and 7 days. Data were analyzed using the Weibull distribution. The failure mode was accessed by stereomicroscope and SEM.
Statistical differences were found between 15 min and 7 days for Variolink II/Syntac SC and RelyX ARC/Single Bond, and between 15 min and 24 h for Enforce/Prime&Bond NT Dual-Cure. For C&B/One-Step, difference was found between 15 min and 4 h. Between 24 h and 7 days, only the system RelyX ARC/Single Bond showed a significant increase in the characteristic strength. SEM analysis revealed that the failure involved the hybrid layer/dentin or the hybrid layer/adhesive interfaces, regardless of the time interval and adhesive system.
High characteristic strengths were observed after 15 min when dual-cure cements were used. In general, the values found at 24 h or 7 days were higher than at 15 min. However, there was always a considerable probability of bonding failure at low stress levels for all the systems tested.
This study determined the bond strengths of adhesive resins joined to a feldspathic porcelain (VMK 68) for the purpose of developing the most durable surface preparation for the porcelain. Three porcelain surfaces-ground, air-abraded with alumina, and etched with hydrofluoric acid-were prepared. A two-liquid porcelain conditioner that contained both 4-methacryloyloxyethyl trimellitate anhydride (4-META) and a silane coupler (Porcelain Liner M) was used as the priming agent. Each of the two liquid components of the conditioner was also used individually in order to examine the effects of the respective chemical ingredients on adhesive bonding. Two methyl methacrylate (MMA)-based resins initiated with tri-n-butylborane (TBB) either with or without 4-META (MMA-TBB and 4-META/MMA-TBB resins) were used as the luting agents. Shear bond strengths were determined both before and after thermocycling. Shear testing results indicated that thermocycling was effective for disclosing poor bonding systems, and that both mechanical and chemical retention were indispensable for bonding the porcelain. Of the combinations assessed, etching with hydrofluoric acid followed by two-liquid priming with the Porcelain Liner M material generated the most durable bond strength (33.3 MPa) for the porcelain bonded with the 4-META/MMA-TBB resin (Super-Bond C&B).
The objective of this study was to determine the effect of selected surface treatments on the surface texture of a feldspathic porcelain. The three different etchant treatments were, acidulated phosphate fluoride (APF) applied for 10 min and hydrofluoric acid (HF) applied for 1 and 4 min. After acid treatment, half of the specimens from each group were cleansed with water and others were subjected to ultrasonic cleaning and then dried. Half of the specimens cleansed with two different methods were treated with silane. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the effects of such treatments. Etching with APF displays shallow patterns. Etching for 1 min with HF displays deep channels, pores and precipitates on the surface and as the etching time increased these channels were replaced by larger channels. EDS analyses show that the crystalline precipitates on the etched surfaces, which were not readily soluble in water, were the reaction products of Na, K, Ca, Al, etc. HF displayed a more roughened surface than the APF gel. However, the precipitates remain on the surface after acid application, they can only be removed by ultrasonic cleaning and cannot be removed by rinsing.
The objective of this in vitro study employing the microtensile test was to test the hypothesis that the tensile bond strength of hot-pressed ceramics to composite is controlled by the ceramic microstructure and the ceramic surface treatment.
Hot-pressed IPS Empress (E1) and IPS Empress 2 (E2) ceramic blocks were polished with 1-micron alumina abrasive and treated as follows: group 1: 9.6% hydrofluoric acid (HF) on E1; group 2: 4% acidulated phosphate fluoride (APF) on E1; group 3: silane (S) on E1; group 4: HF + S on E1; group 5: APF + S on E1; group 6: HF on E2; group 7: APF on E2; group 8: S on E2; group 9: HF + S on E2; group 10: APF + S on E2. The surfaces as described above were then treated with Scotchbond Multi-Purpose Plus and covered with composite (Z-100). From the blocks obtained in this manner, specimens for microtensile testing were created by sectioning. Twenty bar specimens for each group were loaded to failure under tension using an Instron testing machine.
Mean tensile bond strength (MPa) and standard deviation values are as follows: (1) 9.9 +/- 1.2; (2) 0; (3) 27.2 +/- 4.8; (4) 20.6 +/- 3.0; (5) 13.6 +/- 4.5; (6) 41.7 +/- 6.7; (7) 19.1 +/- 2.6; (8) 30.1 +/- 5.3; (9) 56.1 +/- 4.1; (10) 36.9 +/- 3.9. All fractures occurred within the adhesion zone. SEM images of chemically etched specimens revealed that HF produced greater surface degradation and greater bond strength than APF for both E1 and E2 ceramics. The mean bond strength of groups 6 through 10 (E2) was significantly greater than that of groups 1 through 5 (E1) for each treatment condition.
The tensile fracture resistance of the composite-ceramic adhesion zones is controlled primarily by ceramic microstructure and ceramic surface treatment.