No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Effect of Hydrofluoric Acid Etching on Shear Bond Strength of an Indirect Resin Composite to an Adhesive Cement
Abstract
This study evaluated the effect of 1% hydrofluoric acid (HF) treatment on the bonding of an adhesive cement (Panavia F 2.0) to an indirect resin composite (Estenia C&B). Pairs of composite disks (10 and 8 mm in diameter by 3 mm thickness) were prepared. Adhesive surfaces were pretreated with either airborne particle abrasion or HF etching before being soaked for 30 seconds, five minutes or 10 minutes, with or without application of silane coupling agent. Adhesive specimens were fabricated by cementing a pair of treated disks. Shear bond strength was determined before and after 50,000 times of thermocycling (4 and 60 degrees C). All data were statistically analyzed using two-way ANOVA and Bonferroni's test (a=0.05). Bond strength achieved with five minutes of HF etching (18.3+/-1.1 MPa) was significantly higher (P=0.0025) than that obtained with airborne particle abrasion followed by application of silane coupling agent (14.3+/-1.8 MPa) after thermocycling.
... Hydrofluoric acid (HF) dissolves the SiO 2 in ceramics, making it an effective pretreatment method to roughen ceramic surfaces 20,21) . Resin composites also contain SiO2 fillers, and HF treatment was reported to roughen resin composite surfaces prior to bonding 18,22) . However, few studies have examined HF pretreatment of CAD/CAM resin composite blocks 18,23,24) , and, to the best of our knowledge, no reports are available on the shear bond strength between CAD/CAM resin composites treated with HF and resin composites for core build-up. ...
... The setup composes of a single adhesive interface between two materials as the case of adhesive and substrate materials 24,[26][27][28][29][30] . Other is the setup with two adhesive interfaces among three materials as the case of two substrate bonded with one adhesive 18,22,23,[31][32][33] . Since a dental luting cement is the material which is applied with a form of very thin layer, it could be hard to determine the true adhesive strength between the cement layer and the substrate such as CAD/CAM resin composite or core build-up materials in this study. ...
... The self-adhesive resin cement (G-CEM ONE) contained MDP and methacrylic acid ester for adhesion. It is well known that γ-MPTS is an effective priming agent to bond SiO 2 filler particles in resin composites, and that MDP or methacrylic acid ester provides a priming effect on the resin matrix in composites [17][18][19]22,23,34) . ...
This study examined the effects of sandblasting, hydrofluoric acid etching and priming on the shear bond strength of self-adhesive resin cement between seven different CAD/CAM resin composites and a resin composite core material at 24-h after cement mixing. Five surface treatments [control (C), sandblasting (S), priming (P), sandblasting with priming (SP), and 9% HF etching with priming (HFP)] were performed respectively for disc specimens of CAD/CAM blocks. There were no significant differences in bond strength among the C, S, and P, except for one block (p>0.05). SP showed a greater bond strength than S. Weibull moduli were not changed significantly among all treatments for all blocks, whereas the strengths with 5% and 95% failure probability of SP and HFP showed greater values than the others. The bond strengths of HFP were comparable to those of SP. Priming after sandblasting or HF etching could be effective to increase the bond strength of CAD/CAM blocks.
... [13] Occasionally, in the absence of specific equipment and given the need for reconditioning the orthodontic bracket, the practitioner is supposed to find alternative methods to carry out this procedure. Hydrofluoric acid (HF) is a chemical agent that affects the composite surface morphology, [19,20] and it is used in many procedures in dentistry. In repairs performed on resin composite restorations, HF is applied to create microretentions at the restoration surface to improve bonding between the old and the new composite materials. ...
... In repairs performed on resin composite restorations, HF is applied to create microretentions at the restoration surface to improve bonding between the old and the new composite materials. [20] HF has shown promising results when used in the repair of resin composites or cementation of indirect resin restorations. [20] However, there are doubts in relation to the use of HF to improve the bonding of debonded brackets to dental enamel. ...
... [20] HF has shown promising results when used in the repair of resin composites or cementation of indirect resin restorations. [20] However, there are doubts in relation to the use of HF to improve the bonding of debonded brackets to dental enamel. Thus, the effectiveness of HF etching on the bond strength of debonded metallic brackets needs to be further investigated. ...
Context: Bracket debonding is a common problem during orthodontic treatment. This type of failure is associated to masticatory forces, poor adhesion, and the need for repositioning the piece.
Aims: The objective of this work was to compare the shear bond strength of debonded brackets that were reconditioned using different protocols (alumina blasting versus hydrofluoric etching).
Settings and Design: This was an in vitro experimental study with 45 stainless steel orthodontic brackets.
Subjects and Methods: They were randomly divided into three groups: (1) New brackets (n = 15), (2) brackets reconditioned using 10% hydrofluoric acid for 60 s (n = 15), and (3) brackets reconditioned by aluminum oxide blasting until complete removal of the remaining resin (n = 15). In Groups 2 and 3, the insertion of composite resin proceeded in two stages to simulate a type of bracket failure in which the bonding resin was left at the bracket base. For the shear test, the assembly composed by the metallic support, and specimen was taken to the Instron universal testing machine in which the specimens were loaded using a semicircle-shaped active tip in the region of the bonding interface parallel to the surface of the bracket at a speed of 0.5 mm/min.
Statistical Analysis Used: The data were subjected to D′Agostino′s normality test to have their distribution checked. Analysis of variance and Tukey′s test (P < 0.01) were used to compare the findings between groups.
Results: The results indicated that Group 1 (new brackets) showed higher bond strength than that obtained for the group treated with hydrofluoric acid (Group 2, P < 0.01). The bond strength value obtained for the group treated with alumina blasting (Group 3) was statistically similar to those obtained for Groups 1 and 2.
Conclusions: The aluminum oxide blasting technique was effective for the reconditioning of orthodontic brackets. Nevertheless, the reconditioning technique using 10% fluoridric acid for 60 s was not efficient for clinical use.
... from the organic matrix of the resin cement encouraged the use of surface treatments to improve bond strength (BS). Sandblasting with aluminum oxide [3][4][5][6][7][8][9][10][11] or silica coating [5,12] have been used to enhance mechanical interlocking between composite or ceramic materials and resin cement, improving the BS values. [3,8,10,[12][13][14][15][16][17][18][19][20][21] As regards chemical treatments, there is controversy in the literature about the action of hydrofluoric acid etching on polymer surfaces; that is, it showed to improve [9] and to reduce [4,6,10,[12][13][14][15][16]18,22] the BS values. ...
... Sandblasting with aluminum oxide [3][4][5][6][7][8][9][10][11] or silica coating [5,12] have been used to enhance mechanical interlocking between composite or ceramic materials and resin cement, improving the BS values. [3,8,10,[12][13][14][15][16][17][18][19][20][21] As regards chemical treatments, there is controversy in the literature about the action of hydrofluoric acid etching on polymer surfaces; that is, it showed to improve [9] and to reduce [4,6,10,[12][13][14][15][16]18,22] the BS values. ...
... As regards silane coupling agents, the better wettability of the roughened surface, created by its application on the substrate, [23] has been related to the higher values of BS to dental structure of indirect composites. [8] However, in other studies, silanation after sandblasting [3,9,10,24] or acid etching [9,14] did not influence the BS values. ...
Several surface treatments could be used to improve the bond strength (BS) between indirect composites and cement.
To evaluate the BS of an indirect composite submitted to different surface treatments, cemented to bovine dentin.
One hundred and fifty conical cavities were prepared in slices of bovine dentin and bulk filled with the composite.
After curing and removal from the cavity, the restorations were treated according to the groups (n = 10): C-untreated, S-Sandblasting; SS-Sandblasting + silane; F-hydrofluoric acid; FS-hydrofluoric acid + silane; SF-Sandblasting + hydrofluoric acid; SFS-Sandblasting + hydrofluoric acid + silane; E-ethanol; ES-ethanol + silane; SE-Sandblasting + ethanol; SES-Sandblasting + ethanol + silane; P-H2O2; PS-H2O2 + silane; SP-Sandblasting + H2O2; SPS-Sandblasting + H2O2 + silane. After cementation, push-out test was performed in a universal testing machine.
Data were submitted to nonparametric tests (Kruskal-Wallis and Mann-Whitney U-tests, α = 0.05). The failure mode was observed under a stereomicroscope and the topography by scanning electronic microscopy (SEM).
Sandblasted groups led to the highest BS values, (P < 0.001), except for the SFS group. SE, SES, and SPS led to higher BS values than S and SS groups (P < 0.05). F, E andPgroups showed the lowest BS values. The number of cohesive or mixed failures was related to higher BS values. SEM evaluation showed major irregularities only for sandblasted groups.
Sandblasting was a safe surface treatment for the indirect composite, increasing the BS values. Hydrofluoric acid applied after sandblasting damaged the BS values and should not be recommended while ethanol and H2O2, when applied after sandblasting, were effective in increasing BS values.
... For indirectly fabricated restorations -eg, ceramic and indirect composite restorations-, the weakest part of the restoration is the bond between the resin (Kawai et al.,'94;Shinkai et al.,'95) and several researchers (Hummel et al., '97;Hori et al., 2008;Kimyai et al., 2013) evaluated the effect of the surface treatments in attempt to improve its bonding potential. While some of them advocated that to obtain a mechanical retention by air-abrasion with Al 2 O 3 particles (Ozcan et al., 2005;Hori et al., 2008), acidetching with hydrofluoric acid (Hori et al., 2008) or phosphoric acid (Ozcan et al., 2007) and laser irradiations (Kimyai et al., 2013) was an important factor in developing high bond strength between resin cement and restorations, others said that bond strength (BS) increased when a silane coupling agents applied on the surface for to obtain a chemical bonding (Trajtenberg and Powers, 2004;Hori et al., 2008). ...
... For indirectly fabricated restorations -eg, ceramic and indirect composite restorations-, the weakest part of the restoration is the bond between the resin (Kawai et al.,'94;Shinkai et al.,'95) and several researchers (Hummel et al., '97;Hori et al., 2008;Kimyai et al., 2013) evaluated the effect of the surface treatments in attempt to improve its bonding potential. While some of them advocated that to obtain a mechanical retention by air-abrasion with Al 2 O 3 particles (Ozcan et al., 2005;Hori et al., 2008), acidetching with hydrofluoric acid (Hori et al., 2008) or phosphoric acid (Ozcan et al., 2007) and laser irradiations (Kimyai et al., 2013) was an important factor in developing high bond strength between resin cement and restorations, others said that bond strength (BS) increased when a silane coupling agents applied on the surface for to obtain a chemical bonding (Trajtenberg and Powers, 2004;Hori et al., 2008). ...
... For indirectly fabricated restorations -eg, ceramic and indirect composite restorations-, the weakest part of the restoration is the bond between the resin (Kawai et al.,'94;Shinkai et al.,'95) and several researchers (Hummel et al., '97;Hori et al., 2008;Kimyai et al., 2013) evaluated the effect of the surface treatments in attempt to improve its bonding potential. While some of them advocated that to obtain a mechanical retention by air-abrasion with Al 2 O 3 particles (Ozcan et al., 2005;Hori et al., 2008), acidetching with hydrofluoric acid (Hori et al., 2008) or phosphoric acid (Ozcan et al., 2007) and laser irradiations (Kimyai et al., 2013) was an important factor in developing high bond strength between resin cement and restorations, others said that bond strength (BS) increased when a silane coupling agents applied on the surface for to obtain a chemical bonding (Trajtenberg and Powers, 2004;Hori et al., 2008). ...
Debonding at the composite-adhesive interface is a major problem for indirect composite restorations. The aim of this study was to evaluate the bond strength (BS) of an indirect composite resin after various surface treatments (air-abrasion with Al2O3, phosphoric acid-etchig and different applications of NdYAG laser irradiations). Fifty composite disks were subjected to secondary curing to complete polymerization and randomly divided into five experimental groups (n = 10) including Group 1, untreated (control); Group 2, phosphoric acid-etched; Group 3, air-abrasion with Al2O3; Group 4, Nd:YAG laser irradiated with non-contact and Group 5, Nd:YAG laser irradiated with contact. They were then bonded to resin cement and shear BS was determined in a universal testing device at a crosshead speed of 1 mm/min. One way analysis of variance (ANOVA) and Tukey post-hoc tests were used to analyze the BS values. The highest BS value was observed in Group 4 and followed by Group 3. Tukey test showed that there was no statistical difference between Group1, 2 and 5. Furthermore, differences in BSs between Group 4 and the other groups except Group 3 were significant (p < 0.05) and also there were significant differences in BSs between Group 3 to 1 and Group 3 to 2 (p < 0.05). This study reveals that air-abrasion with Al2O3 and Nd:YAG laser irradiation with non-contact provided a significant increase in BS between indirect composite and resin cement. SCANNING 9999:XX–XX, 2014. © 2014 Wiley Periodicals, Inc.
... In contrast with high-strength ceramics, acid-etching with HF solutions between 2.5% and 10% applied for 1 to 3 minutes plus usage of a silane is reported as the best surface-conditioning protocol. 1,5,70 Hori and colleagues 30 detected that after TC, 1% HF etching for 5 minutes is also an adequate pretreatment method for prosthetic composites. However, according to them, neither etching time nor etchant concentration were significantly relevant to bond strength. ...
... In most of the included studies, 6,10,11,[29][30][31]34 dual-curing resin cements were used. They have proven successful throughout the last decades and are characterized by good retention and esthetics. ...
... Moreover, a total of 10 studies were added through hand-search of the bibliographies of the 12 studies. Following detailed analysis, a final number of 18 studies were selected for review.6,[10][11][12][28][29][30][31][32][33][34][35][36][37][38][39][40][41] ...
Statement of the ProblemResin bonding is essential for clinical longevity of indirect restorations. Especially in light of the increasing popularity of computer-aided design/computer-aided manufacturing-fabricated indirect restorations, there is a need to assess optimal bonding protocols for new ceramic/polymer materials and indirect composites.Purpose of the StudyThe aim of this article was to review and assess the current scientific evidence on the resin bond to indirect composite and new ceramic/polymer materials.Materials and Methods
An electronic PubMed database search was conducted from 1966 to September 2013 for in vitro studies pertaining the resin bond to indirect composite and new ceramic/polymer materials.ResultsThe search revealed 198 titles. Full-text screening was carried out for 43 studies, yielding 18 relevant articles that complied with inclusion criteria. No relevant studies could be identified regarding new ceramic/polymer materials. Most common surface treatments are aluminum-oxide air-abrasion, silane treatment, and hydrofluoric acid-etching for indirect composite restoration. Self-adhesive cements achieve lower bond strengths in comparison with etch-and-rinse systems. Thermocycling has a greater impact on bonding behavior than water storage.Conclusions
Air-particle abrasion and additional silane treatment should be applied to enhance the resin bond to laboratory-processed composites. However, there is an urgent need for in vitro studies that evaluate the bond strength to new ceramic/polymer materials.Clinical SignificanceThis article reviews the available dental literature on resin bond of laboratory composites and gives scientifically based guidance for their successful placement. Furthermore, this review demonstrated that future research for new ceramic/polymer materials is required.
... Bonding relies upon mechanical retention and residual free carbon bonds for chemical adhesion [4]. Several surface treatments of indirect composite restorations have been proposed in order to improve the bond between indirect composite restoration and resin cement [3,5]. Increasing roughness of indirect composites by several techniques provides better mechanical interlocking and increases the probability of finding residual free carbons through the larger surface area [8]. ...
... Increasing roughness of indirect composites by several techniques provides better mechanical interlocking and increases the probability of finding residual free carbons through the larger surface area [8]. Some of these techniques include airborne particle abrasion [3], hydrofluoric acid [5], roughening with diamond points, or carbide burs [6]. ...
... Silane agents are bifunctional molecules used to create a chemical bond between the inorganic fillers of the indirect composite and the methacrylate monomers of the resin cement matrix. The silanol group of a silane molecule reacts with silica on the glass filler surface, and the methacrylate group in silane molecule forms a covalent bond with the resin matrix [5]. Moreover, silane agents increase the wettability of the composite by making the surface hydrophobic [3,4,7]. ...
Objectives
The objective of this study was to determine microtensile bond strength (μTBS) to dentin of three self-adhesive and a total-etch resin cements used for luting different treated indirect composites.
Materials and methods
Composite overlays (Filtek Z250) were prepared. Their intaglio surfaces were ground with 600-grit SiC papers and randomly assigned to three different surface treatments: no treatment, silane application (RelyX Ceramic Primer), and silane agent followed by a bonding agent (Adper Scotchbond 1 XT). The composite overlays were luted to flat dentin surfaces of extracted human third molars using the following self-adhesive resin cements: RelyX Unicem, Maxcem Elite and G-Cem, and a total-etch resin cement, RelyX ARC. The bonded assemblies were stored in water (24 h, 37 °C) and subsequently prepared for μTBS testing. Beams of approximately 1 mm2 were tested in tension at 1 mm/min in a universal tester (Instron 3345). Data were analyzed by two-way ANOVA and Student–Newman–Keuls tests (α = 0.05).
Results
A significant influence of the resin cement used was detected. Composite surface treatment and the interaction between the resin cement applied and surface treatment did not affect μTBS.
Conclusions
Surface treatment of indirect resin composite did not improve the μTBS results of dentin/composite overlay complex. Self-adhesive resin cements tested obtained lower μTBS than the total-etch resin cement RelyX ARC. Specimens luted with Maxcem Elite exhibited the highest percentage of pretesting failures.
Clinical relevance
Surface treatment of indirect resin composite with silane or silane followed by a bonding agent did not affect bond strength to dentin.
... [13][14][15] The chemical method is achieved by hydrofluoric acid etching and a silane primer application. 16,17 The bond between provisional materials and OBs is affected by different factors, including the type of adhesive material, the provisional material, the storage time after bonding, and materials aging. 1,2,15,18,19 The strength of this bond should prevent the failure caused by the orthodontic forces, mastication, and other oral functions. ...
... [12][13][14][15] Many researchers concluded that airborne particle abrasion enhances roughness on the composite via non-selective degradation, thus producing microroughness, exterminates the resin matrix and maintaining filler particles on the surface for silane application. 13,16 The mean value of the SBS test was constantly higher with the COBs than the MOBs. This may be due to that the relative translucency of COBs allows the transmission of curing light to the cement and subsequently, superior polymerization occurs. ...
Aim:
To assess the impact of different surface treatment protocols on the shear bond strength (SBS) of metal orthodontic brackets (MOBs) and ceramic orthodontic brackets (CBOs) bonded to provisional crowns via the SBS test.
Materials and methods:
A total of 120 provisional indirect composite crowns (SR Nexco; Ivoclar Vivadent) for maxillary first premolars were fabricated and evenly allocated into two groups: MOBs and CBOs. According to the surface treatment protocol, each group was divided into three subgroups: group CO, no treatment; group HF, the surface was etched with 10% hydrofluoric acid; and group SA, the surface was sandblasted followed by silanization. After bracket bonding, the samples were subjected to 3,000 thermocycles between 5°C and 55°C. SBS was evaluated using a universal testing machine at a crosshead speed of 1 mm/minute and the adhesive remnant index (ARI) was identified. For statistical analysis, ANOVA and Tukey HSD post hoc tests were performed.
Results:
Mean bond strength values for CBOs cemented to control, HF-, and SA-treated subgroups before and after thermocycling were (9.6 μ 1.4, 6.2 μ 1.1), (17.8 μ 2.1, 13.8 μ 1.3), and (17.2 μ 1.4, 12.1 μ 1.8) MPa, respectively. For the metallic brackets, the results were (7.7 μ 2.3, 3.9 μ 1.4), (15.5 μ 1.6, 12.8 μ 1.2), and (15 μ 1.2, 11.2 μ 1.6) MPa, respectively. There was a significant difference (p = 0.000) between ceramic and metallic bracket groups.
Conclusion:
Conditioning of indirect composite provisional crowns either with HF or SA was significantly affecting the adhesion to both bracket types.
Clinical significance:
Increasing the bond strength between provisional crowns and orthodontic brackets (OBs) may improve the treatment standard provided to patients.
... (3) Therefore, eventually the old restora- tion needs to be repaired or replaced and on the other hand, since the replacement of these res- torations is time consuming and leads to loss of some dental structure, repair of these restorations is preferred over their replacement. (4)(5)(6)(7) The im- portant factor is the bond strength between the new and aged resin composites. (8) Usually, bonding between two resin compos- ite layers is possible in the presence of an oxygen inhibited non-polymerized surface, and since old restorations lack this surface, various techniques have been presented for surface treatment. ...
... The evaluated techniques include the use of diamond burs, sandblasting with 50µ aluminum oxide par- ticles, sandblasting with aluminum oxide parti- cles covered with silica (cojet) and etching with hydrofluoric acid. (1)(2)(3)(4)9) In multiple studies, sandblasting has been in- troduced as the best surface treatment method for the aged resin composite but considering the different composition of resin composites and differences in the size and type of filler parti- cles such as (Macro-filled, Micro-filled, Micro- hybrid, Nano-fill and Nano-hybrid) and with the invention of novel Silorane-base composites con- taining different compositions, sandblasting can produce surfaces with different degrees of sur- face roughness. (8) Considering that a comprehensive study on si- multaneous evaluation of resin composite surface roughness and bond strength after sandblasting is not available, the present study was performed to compare the impact of resin composite types on bond strength and surface roughness after sand- blasting. ...
Background and Aim: One of the major problems with resin composite restorations is the weakness of bonding between the new and aged composites. Since appropriate micromechanical retention is necessary for the repair of aged resin composite restorations, the level of surface roughness after sandblasting can be influential in this regard. Considering the diverse composition of available resin composites in the market, the present study was performed to compare the impact of four resin composite types: Micro-hybrid (Z250), Nano-fill (Z350XT), Nano-hybrid (Z250XT) and Silorane-base (p90) on the repaired bond strength and surface roughness after sandblasting.
Methods and Materials: In this in-vitro experimental study, 44 resin composite discs with the diameter of 6mm and height of 2mm were divided to 4 groups of Micro-hybrid, Nano-fill, Nano-hybrid and Silorane-base and from 11 samples of each resin composite type, one sample was evaluated for surface roughness level before and after sandblasting with Atomic Force Microscope (AFM) and 10 samples were tested for shear bond strength in universal testing machine.
Results:The findings indicated that Micro-hybrid resin composite had the highest shear bond strength (37.8±6.4 MPa) followed respectively by Nano-fill (30 ±3.8 MPa), Silorane-base (17.9±4 MPa) and Nano-hybrid composites (7.6±1.9 MPa). The differences between all groups were significant (p
... [1] Although air-abrasion improves adhesion in repair actions, it may damage the margins of restorations made of IRCs. [36][37][38][39][40] Hence, the use of small particle size such as 50 μm Al 2 O 3 should be preferred to 110 μm Al 2 O 3 or silica. Moreover, air-abrasion exposes the particles on the surface that eventually facilitates the silanization on larger area of filler particles. ...
... The dissolved glass filler particles on the IRC surface then generates micromechanical retention. [37,41] Silane application after hydrofluoric acid etching would enhance the bond strength owing to filler particles at the surface presenting potential sites for silanization. [1] According to some studies, etching could also cause total dissolution of exposed inorganic filler particles. ...
This study evaluated the adhesion of conventional and self-adhesive resin cements to indirect resin composite (IRC) using different surface conditioning methods. Cylindrical IRC specimens (N = 192) were randomly assigned to four surface conditioning methods (n = 8 per group): (a) Control group, (b) Hydrofluoric acid, (c) Tribochemical silica-coating, and (d) 50 μm Al2O3 air-abrasion. Specimen surfaces were finished using silicon carbide papers up to 600 grit under water irrigation, rinsed and dried. Direct composite blocks were bonded to IRC specimens using three conventional resin cements (Multilink, Panavia F2.0, and Resicem) and three self-adhesive resin cements (RelyX U100, Gcem, Speed Cem). Specimens were subjected to shear bond strength test in a Universal Testing Machine (0.5 mm/min). Failure types were categorized as mixed, adhesive and cohesive. Data were analyzed using 2-way ANOVA and Tukey’s tests. Two-parameter Weibull modulus, scale (m) and shape (0) were calculated. The bond strength results (MPa) were significantly affected by the surface conditioning method (p < 0.0001) and cement type (p < 0.001). For Panavia F2.0, Resicem, air-abrasion with 50 μm Al2O3 significantly increased the results (22.6 ± 6.5, 26.2 ± 6.5, respectively) compared to other conditioning methods (13.6 ± 1.4–21.9 ± 3.1) but for Multilink, hydrofluoric acid etching (20.5 ± 3.5) showed significantly higher results (p < 0.01). For the self-adhesive resin cements, air-abrasion with 50 μm Al2O3 significantly increased the results compared to other conditioning methods, except for RelyX U100 (p < 0.05). After air-abrasion with Al2O3, Gcem, (11.64), RelyX U100 (9.05), and SpeedCem (8.29) presented higher Weilbul moduli. Exclusively cohesive failure in the IRC was observed with RelyX U100 and Speedcem after Al2O3 air-abrasion.
... Moreover, they show several advantages over ceramic inlays or onlays as they cause less wear of the opposing dentition, are easier to finish, polish and repair (1). The long-term clinical success of these restorations is largely determined by the bonding effectiveness of the resin's luting agent to tooth substrate and to processed resin composite (2), as indirect procedures double the adhesive interfaces (3). Adhesion of resin cement to processed composite restorations is challenging. ...
... However, there is no consensus about the influence of intermediary agents (silane coupling agent and dentin adhesive) on adhesive properties of composite restorations (4). Silane coupling agents are bifunctional molecules used to induce a chemical bond between the inorganic fillers of the indirect composite and the methacrylate monomers of the resin cement matrix (2). Moreover, silane agents increase the wettability of the composite by making the surface hydrophobic (4). ...
Background:
No specific indications about the pre-treatment of indirect composite restorations is provided by the manufacturers of most self-adhesive resin cements. The potential effect of silane treatment to the bond strength of the complete tooth/indirect restoration complex is not available.The aim of this study was to determine the contribution of different surface treatments on microtensile bond strength of composite overlays to dentin using several self-adhesive resin cements and a total-etch one.
Material and methods:
Composite overlays were fabricated and bonding surfaces were airborne-particle abraded and randomly assigned to two different surface treatments: no treatment or silane application (RelyX Ceramic Primer) followed by an adhesive (Adper Scotchbond 1 XT). Composite overlays were luted to flat dentin surfaces using the following self-adhesive resin cements: RelyX Unicem, G-Cem, Speedcem, Maxcem Elite or Smartcem2, and the total-etch resin cement RelyX ARC. After 24 h, bonded specimens were cut into sticks 1 mm thick and stressed in tension until failure. Two-way ANOVA and SNK tests were applied at α=0.05.
Results:
Bond strength values were significantly influenced by the resin cement used (p<0.001). However, composite surface treatment and the interaction between the resin cement applied and surface treatment did not significantly affect dentin bond strength (p>0.05). All self-adhesive resin cements showed lower bond strength values than the total-etch RelyX ARC. Among self-adhesive resin cements, RelyX Unicem and G-Cem attained statistically higher bond strength values. Smartcem2 and Maxcem Elite exhibited 80-90% of pre-test failures.
Conclusions:
The silane and adhesive application after indirect resin composite sandblasting did not improve the bond strength of dentin-composite overlay complex. Selection of the resin cement seems to be a more relevant factor when bonding indirect composites to dentin than its surface treatment. Key words:Bond strength, self-adhesive cement, silane, dentin, indirect composite.
... Moreover, the concentration of the hydrofluoric acid etching used in the current study was higher (9% for 60 seconds). This concentration might have a negative effect on the indirect composite because it had a dissolving action on the filler particles used (20,21) In the present study, the results exhibited that the two types of indirect composite treated by sandblasting followed by silane application showed significant higher bond strength values than sandblasting followed by monobond etch and prime. These findings agreed with those reported by El Damnhoury et al (23) who concluded that sandblasting followed by silane application recorded higher bond strength values than monobond etch and prime when applied in indirect composite resins. ...
... The effectiveness of surface pretreatments depends not only on the operators' skills and experience but also on the quality of specific equipment, along with their sensitive manipulation, used to accomplish such procedures. During the last ten years, a rapid development of new resin cements with specific properties has been observed, which may allow clinicians to provide adequate bond strength but with simplified and user-friendly surface treatments [22][23][24]. Nevertheless, there is limited evidence on the bond strength of newer self-adhesive resin cements compared to that of conventional or self-adhesive resin-based and resin-modified glass ionomer cements (RMGICs) when bonded to a variety of prosthetic substrates. ...
This study aimed at evaluating the shear bond strength (SBS) of modern self-adhesive resin cements and resin-modified glass ionomer cements applied to different prosthetic substrates. Zirconia, lithium-disilicate glass-ceramic and a noble metal alloy were used as bonding substrates. They were all sand-blasted with alumina, while LD was further etched with 9.6% hydrofluoric acid (10 s). A light-curing resin-modified glass ionomer cement (3M-GIC: Ketac Cem Plus) and a self-curing resin-modified glass ionomer cement (GC-GIC: FujiCEM 2) were compared to self-adhesive resin cements (PAN: Panavia SA Universal) and (3M-RES: Rely X Unicem 2). Ten specimens for each substrate were produced and up to five cylinders of each cement were bonded to each substrate. The shear bond strength (SBS) was evaluated after 24 h or after thermocycling (TC) aging (5000 cycles). The data was statistically analysed by two-way ANOVA and Student–Newman–Keuls test (α = 0.05). Failure modes were analysed through stereoscopic microscopy. The greatest SBS was attained with PAN, whilst 3M-GIC showed the lowest SBS and failed prevalently in adhesive mode. No difference in SBS was observed between GC-GIC and 3M-RES. After TC aging, all cements showed significant drop (p < 0.05) in SBS, but PAN showed the greatest SBS. Reliable bond strength to prosthetic substrates can be achieved with specific universal resin-luting cements and may be an alternative to glass ionomer cements when luting alloy substrates.
... The use of indirect resin composites restorations ensures a better bond strength because the impact of polymerization shrinkage on adhesion in dentin is insignificant (2). The additional polymerization process enhances the physical and mechanical properties of indirect composite resins (3), besides to decrease a chemical bonding capacity because the quantity of residual free carbon bonds decreases. To improve bond strength of indirect composite resins to dentin different surface treatments have been proposed. ...
Background:
To evaluate the microtensile bond strength of indirect resin composite bonded to dentin using five different adhesives strategies.
Material and methods:
Forty specimens (Solidex) were produced and randomly into five groups with different adhesives strategies: (G1)- Single Bond Universal + etch + silane + RelyX Ultimate, (G2)- Single Bond Universal + silane + RelyX Ultimate, (G3)- Single Bond Universal + etch + RelyX Ultimate, (G4)- Single Bond Universal + RelyX Ultimate, and (G5)-Scotchbond Multi-purpose + RelyX ARC. After cementation the specimens were stored in 100% humidity for 24hours at 37°C. The specimens were sectioned perpendicular to the adhesive interface to obtain beams and submitted to microtensile test. Microtensile values were expressed in MPa and analyzed by one-way ANOVA and multiple comparison Tukey tests (α=0.05).
Results:
The mean bond strength in MPa groups were: G1=11,48, G2=14,15, G3=16,95, G4=17,03 and G5=16,80. Statistical analysis showed that the bond strength values were not significantly affected by the different adhesive strategies.
Conclusions:
Cementation of dentin to indirect resin composite cannot be significantly affected by different adhesive strategies used. The specimens treated with silane, etch associated with Single bond universal did not increase bond strength values. Key words:Adhesives, dental cements, dentin.
... There are many factors that greatly influence the goal of achieving and maintaining an adequate adhesion. These factors include: A well-established surface treatments at both the tooth and restoration side (5) , furthermore, the kind of resin composite cement as well as the curing mode of both adhesive and composite cement. An optimum cure of the cement is indispensable in order to achieve good mechanical properties and avoid cement ditching with its consequences of a higher risk on secondary caries and endodontic/periodontal complications (6) . ...
... Upon washing, the loosely bounded glass filler particles were washed away creating the surface micro-porosities. 24 Furthermore, the HF acid was able to dissolve the glass filler particles and led to filler dissolution. This in turn led to the disintegration of the filler/matrix interface. ...
Objective: To evaluate the effect of different chemical surface treatments on the shear bond strength (SBS) durability of resin cement to a chair side indirect resin composite material.
Materials and methods: In total, 200 resin composite discs (4mmx4mm) and 200 resin composite cylinders (2mmx4mm) were prepared and divided into 20 experimental groups according to the two experimental factors in this study; Factor 1, Surface treatment, 10 groups [No-Treatment (NT); No-Treatment+Silane (NT+S); 35% Phosphoric acid etching (AE); 35% Phosphoric acid etching+Silane (AE+S); 9.5% Hydrofluoric acid (HF); 9.5% Hydrofuoric acid+Silane (HF+S); 30% Hydrogen peroxide (HP); 30% Hydrogen peroxide+Silane (HP+S); 20% Potassium permanganate (PP) and 20% Potassium permanganate+Silane (PP+S)] and Factor 2: Storage time, 2 groups [24 hours and 1-year]. After each respective surface treatment, each resin composite cylinder was bonded to a resin composite disc using a dual-cured resin cement. Half of the specimens were stored in distilled water for 24 hours and the other half was stored in distilled water for 1-year. The SBS testing was run at a cross-head speed of 0.5mm/minute. Data were statistically analyzed using Two-way ANOVA/Tukey HSD test. Significant level was set at p=0.05. Additional 5 resin composite discs (7mmx2mm) were examined under SEM to evaluate the surface topography after each chemical treatment.
Results: Two-Way ANOVA showed that factors “surface treatment”, “storage time” and “surface treatment x storage time” had significant effect on SBS (P<0.001). The NT and PP groups showed the significant lower SBS among all surface treatments used (P<0.05). The SBS was dropped significantly after 1-year storage time in all surface treatment used (P<0.05).
Conclusions: The SBS of the dual-cured resin cement to the chair-side resin composite indirect material was not stable after 1-year storage period.
... Kumlama, asit veya elmas frezle pürüzlendirme ve dental lazerler tamir işlemi sırasında bağlantı gücünü artırmak için kullanılan pürüzlendirme yöntemleri arasında yer almaktadır (8,10). Son yıllarda, mine ve dentin yüzeyinin Er: YAG ve Er, Cr: YSGG lazerlerle pürüzlendirilmesini içeren birçok çalışma gerçekleştirilmiştir. Lazerlerin çalışma prensibi, enerjinin dokudaki su molekülleri tarafından emilmesinden sonra su moleküllerinin aniden ısıtılması ve buharlaşması şeklindedir. ...
... The oxygen-inhibited layer of unpolymerized resin plays a crucial role in the long-term bonding of two composite layers. Because CAD/CAM composites are polymerized under standardized high pressure and temperature, they do not contain the unpolymerized surface layer, similar to aged resin-based composites [9]. Furthermore, due to its increased water adsorption and saturation, the repair strength of aged resin-based composites has been reported to be lower than the cohesive strength of the fresh composite [10]. ...
Limited data are available on the repair bond strength between computer-aided design and manufacturing (CAD/CAM) resin nanoceramics and composite repair materials. Therefore, the purpose of this study was to test the influence of several different surface treatment modalities, intermediate agents and phosphoric acid on the shear bond strength (SBS) of repair composites with water-aged CAD/CAM resin nanoceramics. Three pretreatment and four conditioning methods comprised 12 different groups. A universal testing machine was used to test the SBS. Specimens were examined with a stereomicroscope and scanning electron microscope to determine the fracture mode. The results showed that a combination of the pretreatment and conditioning methods significantly enhanced the SBS of the resin nanoceramic (p:0.001; p < 0.01), while etching with phosphoric acid did not affect the SBS (p:0.841; p > 0.05). This study showed that surface pretreatment in combination with a conditioning method should be used in the repair of CAD/CAM nanoceramics. The highest SBS values were achieved by grinding the surface with a diamond bur followed by silane and adhesive application, whereas the lowest values were obtained in the non-conditioned non-pretreated group.
... quantity of residual free carbon double bonds decreases. 16 Several surface treatments have been proposed to increase composite resin roughness to provide mechanical interlocking of the adhesive 15,[17][18][19][20][21][22][23][24][25][26][27] and to increase the number of unreacted methacrylate groups in the larger surface area created. 28 Specifically, airborneparticle abrasion with alumina has been shown to improve bond strength to repaired composite resin [29][30][31][32] and to indirect composite resin restorations. ...
Statement of problem:
Additional polymerization of indirect composite resins enhances their physical properties but lessens the potential for chemical bonding.
Purpose:
The purpose of this in vitro study was to evaluate the influence of different surface treatments and 6-month water storage on the microtensile bond strength (μTBS) of composite resin onlays.
Material and methods:
Composite resin onlays (Filtek Z250) randomly received 6 different surface treatments: (1) airborne-particle abrasion with 27-μm alumina particles+Adper Scotchbond 1XT adhesive application, (2) airborne-particle abrasion with alumina particles+silane application (ESPE SIL)+Adper Scotchbond 1XT, (3) airborne-particle abrasion with alumina particles+Scotchbond Universal adhesive, (4) tribochemical silica coating with 30-μm particles (CoJet Sand)+Adper Scotchbond 1XT adhesive, (5) tribochemical silica coating+silane application+Adper Scotchbond 1XT, and (6) tribochemical silica coating+Scotchbond Universal adhesive. Onlays were luted to fresh composite resin specimens with RelyX Ultimate resin cement. Bonded assemblies were stored in water for 24 hours or 6 months at 37°C and subjected to the μTBS test. Additional surface-treated composite resin onlays were analyzed with a contact profilometer to determine average roughness, and micromorphologic changes were analyzed with scanning electron microscopy.
Results:
Airborne-particle abrasion with alumina followed by Adper Scotchbond 1XT or Scotchbond Universal adhesive application provided the highest bond strength values at 24 hours. Lower values were obtained after tribochemical silica coating. After 6 months of artificial aging, airborne-particle abrasion with alumina or silica-coated alumina particles followed by Scotchbond Universal application yielded the greatest bond strength results. Airborne-particle abrasion with alumina produced the highest roughness values and a more irregular surface.
Conclusion:
Adhesive selection seems to be relevant to the μTBS of luted composite resin onlays after 6 months of water aging, as specimens treated with Scotchbond Universal, after alumina airborne-particle abrasion or tribochemical silica coating, yielded the highest values and better aging stability.
... quantity of residual free carbon double bonds decreases. 16 Several surface treatments have been proposed to increase composite resin roughness to provide mechanical interlocking of the adhesive 15,[17][18][19][20][21][22][23][24][25][26][27] and to increase the number of unreacted methacrylate groups in the larger surface area created. 28 Specifically, airborneparticle abrasion with alumina has been shown to improve bond strength to repaired composite resin [29][30][31][32] and to indirect composite resin restorations. ...
... Some authors believe that HF acid is harmful for the resin composite 10 or that its application with silane treatment does not reveal significant changes in tensile bond strength 9 . On the other hand, other authors consider that five minutes of HF etching could significantly increase the bond strength compared to airborne particle abrasion followed by application of silane coupling agent 11 . ...
Indirect composites are developed to overcome the shortcomings of direct composites but, the adhesion of resin cements to indirect composites is still difficult. The purpose of this study was to evaluate the surface morphology of indirect resin composite treated by different powers of Er:YAG laser using Scanning Electron Microscopy (SEM).
indirect resin composite blocks (GC Gradia DA2, Japan) with 15× 10 × 10 mm dimensions were made according to manufacturer's instructions (n=7). The bonding surface of these blocks were polished, then the samples were divided to seven groups as follow: Erbium-Doped Yttrium Aluminum Garnet (Er:YAG)laser with output power of 2, 3, 4, 5, 6,7 W (frequency of 20 Hz, very short pulse) and no treatment. Then, the surfaces were evaluated by scanning electron microscope.
The surface treated by Er:YAG laser showed a porous surface. But the amount and pattern of these irregularities differ in each group which may produce micromechanical retention compared to control group with no treatment.
Er:YAG laser can be used as an alternative technique for surface treatment and roughening of indirect resin composites.
... Regarding restoration-surface pre-treatment to adhesively lute indirect composite (and ceramic) restorations, a new socalled 'universal' adhesive (Scotchbond Universal, 3M ESPE) with an in-built silane was introduced. Separate application of a silane primer is claimed to be no longer needed, while in literature various restoration-surface pre-treatments are generally recommended, such as sandblasting with aluminiumoxide (27-50 m), silane coupling, (solely) application of a bonding agent, tribochemical silica sandblasting (Cojet, 3M ESPE), hydrofluoric acid etching, etc. [6][7][8]. ...
To determine the effect of curing mode and restoration-surface pre-treatment on the micro-tensile bond strength (μTBS) to dentin.
Sandblasted CAD/CAM composite blocks (LAVA Ultimate, 3M ESPE) were cemented to bur-cut dentin using either the etch & rinse composite cement Nexus 3 ('NX3', Kerr) with Optibond XTR ('XTR', Kerr), or the self-etch composite cement RelyX Ultimate ('RXU', 3M ESPE) with Scotchbond Universal ('SBU', 3M ESPE). All experimental groups included different 'curing modes' (light-curing of adhesive and cement ('LL'), light-curing of adhesive and auto-cure of cement ('LA'), co-cure of adhesive through light-curing of cement ('AL'), or complete auto-cure ('AA')) and different 'restoration-surface pre-treatments' of the composite block (NX3: either a silane primer (Kerr), or the XTR adhesive; RXU: either silane primer (RelyX Ceramic Primer, 3M ESPE) and SBU, or solely SBU). After water-storage (7 days, 37°C), the μTBS was measured. Additionally, the degree of conversion (DC) of both cements was measured after 10min and after 1 week, either auto-cured (21°C/37°C) or light-cured (directly/through 3-mm CAD/CAM composite).
The linear mixed-effects model (α=0.05) revealed a significant influence of the factors 'curing mode' and 'composite cement', and a less significant effect of the factor 'restoration-surface pre-treatment'. Light-curing 'LL' revealed the highest μTBS, which decreased significantly for all other curing modes. For curing modes 'AA' and 'AL', the lowest μTBS and a high percentage of pre-testing failures were reported. Overall, DC increased with light-curing and incubation time.
The curing mode is decisive for the bonding effectiveness of adhesively luted composite CAD/CAM restorations to dentin.
... ES contained 92 wt% of inorganic fillers 20) and Bis-GMA monomer as a main component of its resin matrix. ...
This study evaluated the effect of abutment materials on the fracture resistance of composite crowns for premolars. Composite crowns were fabricated using two different indirect composite resin materials (Meta Color Prime Art or Estenia C&B) and cemented onto either a metal (Castwell M.C. 12) or composite resin (Build-It FR and FibreKor) abutment with resin cement (Panavia F2.0). Twenty-four specimens were fabricated for four groups (n=6 each) and subjected to 280-N cyclic impact loading at 1.0 Hz. The number of cycles which caused the composite crown to fracture was defined as its fracture resistance. All data were statistically analyzed using ANOVA and the Bonferroni test (α=0.05). Composite crowns cemented onto resin abutments showed higher fracture resistance than those cemented onto metal abutments.
The ideal treatment for restoration of Endodontically-treated teeth (ETT) has been widely discussed in the literature. The main aim of a restoration is to provide a hermetic seal between the oral environment and the root canal system as it has been widely agreed that the coronal seal significantly contributes to the clinical success of an Endodontically-treated tooth in addition and in fact more than the apical seal for prevention of bacterial ingress. In achieving this objective, it is important that the restoration conserves as much possible the tooth structure and contributes to the resistance of the tooth in the long run. With the development and improvement of the adhesive system, Endocrowns have been used as an alternative to the conventional post-core crowns as means for a minimally invasive preparation design, yet at the same time able to provide good aesthetics, better mechanical performance, lower cost and clinic time for the rehabilitation of an endodontically treated tooth.
The aim of the present study was undertaken to investigate the effects of several surface modification methods applied to lithium disilicate glass ceramics (LDCs) on their bonding durability with resin-based cement. The LDC specimens were sectioned using a low-speed diamond cutting machine, crystallized by heating in a furnace, and then subjected to several surface modification treatments such as acid etching, sandblasting, or silica coating with silane coupling agents. Then, a cylindrical titanium with a sandblasted surface was bonded to the surface-modified LDC specimens using resin-based cement. After being either stored in water at 37°C for 24h or subjected to 10,000 and/or 30,000 thermal cycles, the specimens were subjected to a shear bond strength test using a universal testing machine. The surface-modified LDC specimens obtained by combining blasting and silica coating modification treatments showed excellent durability, similar to that of acid-etched specimens. For safer laboratory practice, we recommend using the silica coating method for LDCs prior to applying silane coupling agents.
This study investigated the efficacies of adhesive resin cements (Clearfil SA Luting, Maxcem, G-CEM, RelyX Unicem Clicker, Vitremer Paste) for bonding to Ag-Pd-Cu-Au alloy not surface-pretreated with metal primer. For control, Panavia F 2.0 -developed for use with a proprietary metal primer, Alloy Primer- was tested with and without metal primer application. Pairs of alloy disks (10.0 and 8.0 mm in diameters, 3.0 mm thickness) were air-abraded with alumina and bonded with one of the cements. Shear bond strengths (SBSs) were measured before and after 50,000 times of thermocycling. Among Maxcem, RelyX Unicem Clicker and the control, there were no statistical differences in SBS before and after thermocycling. After thermocycling, Clearfil SA Luting exhibited the highest SBS among all the cements. Results showed that Clearfil SA Luting, Maxcem, and RelyX Unicem Clicker were efficacious for bonding to Ag-Pd-Cu-Au alloy after air abrasion surface treatment for the latter.
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)
Enhancement of bond strength between new and old composite usually requires increasing the surface roughness to promote mechanical interlocking and coating of old composite with unfilled resin bonding agents to advance surface wetting and chemical bonding.
The purpose of this study was to evaluate the effect of combinations of surface treatments and bonding agents on the shear bond strength between new and old composite.
Six surface treatments, two bonding agents, and an untreated control comprised 18 different subgroups.
The use of unfilled resin, alone or combined with silane, was the most effective procedure to enhance the shear bond strength of the repaired composite specimens, irrespective of the surface pretreatment processes. Silanation and unfilled resin slightly but not significantly improved the repair strength compared with unfilled resin alone.
Different combinations of surface treatments and bonding agents affect shear bond strength differently. The highest shear bond strength values were achieved by grinding the surface with green Carborundum stone or sandblasting, whereas the lowest values were obtained with hydrofluoric acid as the surface treatment agent.
The use of resin-based composite materials in operative dentistry is increasing, including applications in stress-bearing areas. However, composite restorations, in common with all restorations, suffer from deterioration and degradation in clinical service. Durable repair alternatives by layering a new composite onto such failed composite restorations, will eliminate unnecessary loss of tooth tissue and repeated insults to the pulp. The objective of this study was to evaluate the effect of three surface conditioning methods on the repair bond strength of a particulate filler resin-composite (PFC) to 5 PFC substrates. The specimens were randomly assigned to one of the following surface conditioning methods: (1) Hydrofluoric (HF) acid gel (9.5%) etching, (2) Air-borne particle abrasion (50 microm Al2O3), (3) Silica coating (30 microm SiOx, CoJet-Sand). After each conditioning method, a silane coupling agent was applied. Adhesive resin was then applied in a thin layer and light polymerized. The low-viscosity diacrylate resin composite was bonded to the conditioned substrates in polyethylene molds. All specimens were tested in dry and thermocycled (6.000, 5-55 degrees C, 30 s) conditions. One-way ANOVA showed significant influence of the surface conditioning methods (p < 0.001), and the PFC types (p < 0.0001) on the shear bond strength values. Significant differences were observed in bond strength values between the acid etched specimens (5.7-14.3 MPa) and those treated with either air-borne particle abrasion (13.0-22.5 MPa) or silica coating (25.5-41.8 MPa) in dry conditions (ANOVA, p < 0.001). After thermocycling, the silica coating process resulted in the highest bond values in all material groups (17.2-30.3 MPa).
A hybrid ceramic, Estenia, is a highly-filled composite for indrect use. The purpose of this study was to measure the shear bond strength between Estenia and six incremental materials: Estenia, Cesead II, Epricord, Gradia, Prossimo, and Solidex. Five specimens were prepared for each group, and all specimens were subjected to shear bond strength testing at a cross-head speed of 1 mm/min. Data were analyzed using two-way ANOVA and Dunnett's T3 test at 95% confidence level. The results indicated that the shear bond strength of Estenia to Estenia was significantly lower than that of any other combinations. Apart from storage condition that was found to influence shear bond strength statistically, thermal cycling of the specimens also tended to decrease the bond strength between Estenia and the incremental materials. It was concluded that regularly-filled composites are suitable to be used as an incremental material facing Estenia in combination technique.
To evaluate the effect of different silane agents and air-drying temperatures on the repair strength of a microfilled hybrid composite.
Composite cylinders (8 x 4 mm) of Gradia Direct Anterior (GC, N=36), stored in a saline solution at 37 degrees C for 1 month, were sandblasted (50-microm aluminium oxide), cleaned (35% phosphoric acid) and randomly divided into six groups (n=6). Two prehydrolyzed silane primers (Monobond-S, Ivoclar-Vivadent, Porcelain Primer, Bisco), a non prehydrolyzed silane primer (Porcelain Liner M, Sun Medical) and three silane/adhesive coupling agents (Porcelain Bond Activator-PBA/Clearfil New Bond, PBA/Clearfil SE Bond, PBA/Clearfil Tri-S Bond, Kuraray) were investigated. Silane-coated surfaces were air dried at two different temperatures (23 degrees C and 38 degrees C) and repairs (8 x 8 mm) were fabricated (Gradia Direct Anterior). Unrepaired composite cylinders (8 x 8 mm, n=6) were used as control to evaluate the cohesive strength of the material. Microtensile bond strength measurements (microTBS) were performed. Results: The silane agent applied (p < 0.001), the airdrying temperature (p < 0.001) and their interaction (p < 0.001) were significant factors (two-way ANOVA, Tukey test; p < 0.05). Silane primers achieved inferior microTBS when air dried at 23 degrees C as compared to silane/adhesive blends. Warm air-drying was significantly beneficial to composite repairs mediated by silane primers. Comparable results were achieved by silane/adhesive couplings at 23 degrees C and 38 degrees C. At 38 degrees C all the intermediate agents resulted in repair microTBS that were comparable to the 24-h cohesive strength of the composite (one-way ANOVA, Dunnett t-tests; p < 0.05).
The chemical interactions between silane primers and compozite substrate may be optimized through warm airdrying. Silane/adhesive couplings were not influenced by the air drying temperature.
Statement of problem. The ceramic composition and microstructure surface of all-ceramic restorations are important components of an effective bonding substrate. Both hydrofluoric acid etching and airborne aluminum oxide particle abrasion produce irregular surfaces necessary for micromechanical bonding. Although surface treatments of feldspathic and leucite porcelains have been studied previously, the high alumina-containing and lithium disilicate ceramics have not been fully investigated. Purpose. The purpose of this study was to assess the surface topography of 6 different ceramics after treatment with either hydrofluoric acid etching or airborne aluminum oxide particle abrasion. Material and methods. Five copings each of IPS Empress, IPS Empress 2 (0.8 mm thick), Cergogold (0.7 mm thick), In-Ceram Alumina, In-Ceram Zirconia, and Procera (0.8 mm thick) were fabricated following the manufacturer's instructions. Each coping was longitudinally sectioned into 4 equal parts by a diamond disk. The resulting sections were then randomly divided into 3 groups depending on subsequent surface treatments: Group 1, specimens without additional surface treatments, as received from the laboratory (control); Group 2, specimens treated by use of airborne particle abrasion with 50-mum aluminum oxide; and Group 3, specimens treated with 10% hydrofluoric acid etching (20 seconds for IPS Empress 2; 60 seconds for IPS Empress and Cergogold; and 2 minutes for In-Ceram Alumina, In-Ceram Zirconia, and Procera). Results. Airborne particle abrasion changed the morphologic surface of IPS Empress, IPS Empress 2, and Cergogold ceramics. The surface topography of these ceramics exhibited shallow irregularities not evident in the control group. For Procera, the 50-mum aluminum oxide airborne particle abrasion produced a flattened surface. Airborne particle abrasion of In-Ceram Alumina and In-Ceram Zirconia did not change the morphologic characteristics and the same shallows pits found in the control group remained. For IPS Empress 2, 10% hydrofluoric acid etching produced elongated crystals scattered with shallow irregularities. For IPS Empress and Cergogold, the morphologic characteristic was honeycomb-like on the ceramic surface. The surface treatment of In-Ceram Alumina, In-Ceram Zirconia, and Procera did not change their superficial structure. Conclusion. Hydrofluoric acid etching and airborne particle abrasion with 50-mum aluminum oxide increased the irregularities on the surface of IPS Empress, IPS Empress 2, and Cergogold ceramics. Similar treatment of In-Ceram Alumina, In-Ceram Zirconia, and Procera did not change their morphologic microstructure.
The contact wear behavior of a dental ceramic composite containing 92 wt% silica glass and alumina filler particles in a polymeric resin matrix was examined. Because this composite is used for dental restorations, the tests were conducted under contact conditions that were relevant to those that exist in the mouth. Wear tests were conducted on a pin-on-disk tribometer with water as a lubricant. Results on wear volume as a function of load indicated two distinct regimes of wear. The wear volume increased slightly as the load was increased from 1 to 5 N. As the load was further increased to 10 N, the wear volume increased by one order of magnitude. At loads above 10 N (up to a maximum of 20 N), the wear volume was found to be independent of load. Examination of the wear tracks by SEM revealed that a surface film had formed on the wear tracks at all loads. Examination of these films by TEM showed that the films contained a mixture of small gamma-Al2O3 crystallites and glass particles. FTIR analysis of the adhered films indicated the presence of hydrated forms of silica and alumina, suggesting reaction of filler particles with water. Chemical analysis by ICP-MS of water samples collected after the wear tests confirmed the presence of Al and other elemental constituents of the filler particles. It is proposed that three simultaneous processes occur at the sliding contact: tribochemical reactions and film formation, dissolution of the reacted products, and mechanical removal of the film by microfracture. At low loads, wear occurs primarily by a tribochemical mechanism, i.e., formation and dissolution of the reaction products. At higher loads, wear occurs by a combination of tribochemical processes and mechanical detachment of the surface film.
This study evaluated the effectiveness of air abrasion (sandblasting), hydrofluoric acid (HF) etching, and acidulated phosphate fluoride (APF) for composite repair. Five different composites (three hybrids, one small-particle, and one microfill) were used to test the effects of different compositions and particle sizes. A phosphonate resin bonding agent was used for all repair procedures. In general, air abrasion provided the strongest repairs, approximately 60% of cohesive strength. The effect of HF varied with different composites, either improving or reducing the repair strength. APF gave the lowest interfacial bond strengths for all composites except the microfill.
Composite can be cured extraorally to fabricate indirect or direct/indirect restorations. These restorations are bonded to the tooth with a dual-cure resin cement. This study evaluated various methods for treating the surface of an indirect glass-filled composite to improve its bond to enamel. The methods tested were air abrasion (sandblasting), hydrofluoric (HF) acid etching, silanation, and combinations of these techniques. Shear bond strengths were measured for thermocycled and non-thermocycled specimens. Air abrasion, followed by silanation, provided the strongest and most consistent bonds. Etching with 9.6% HF gel decreased the bond strengths obtained by air abrasion. HF alone produced the weakest bonds, with most failures occurring adhesively between the indirect composite and the resin cement.
A new porcelain repair system was developed which uses a two-liquid primer, self-cured opaque resin, and light-cured composite. The primer consisted of two liquids. One component was 4% 3-trimethoxysilylpropyl methacrylate in methyl methacrylate, and the other component was 0.5% ferric chloride in ethanol. A self-curing opaque resin, 4-META/MMA-TBB opaque resin, was used as an adhesive to bind the porcelain and the composite. Adhesive opaque resin was applied on the roughened and primed porcelain. Light-cured composite was placed over the 4-META opaque layer. A shear test was performed for investigation of the strength and durability of the bonding. The result was that for all specimens after 20,000 thermocycles, fracture or crack propagation during the shear test occurred in the porcelain, rather than in the bond. This system may be used to repair fractured porcelain facings without removal of prostheses.
Despite significant improvements in the wear resistance of posterior composite restorations, they still undergo occlusal wear, color change, and surface staining with time. One method of repairing these restorations is re-surfacing the old composite. This study investigated the bonding of new composite to the corresponding old composite material by several different mechanical conditioning steps, chemical conditioning steps, primer conditioning steps, and four posterior composites. Aged composite surfaces were conditioned, re-bonded to new composite, stored in artificial saliva for seven days at 37 degrees C, and tested in shear. The mean shear strength for unrepaired composites was 27 MPa. Optimal re-bond strengths were 88% (Estilux), 77% (Ful-Fil), 92% (Occlusin), and 102% (P-10) of original bulk shear strengths. General linear modeling revealed that the best combination tested was roughening with a D830 diamond bur, conditioning the surface with water, and priming with Scotchbond-1 dentin bonding agent.
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.
Tensile bond strengths among three resin inlay cements and a light-cured and a post-cured hybrid composite prepared with two different surface treatments and three different bond-enhancing liquids were measured in vitro. The resin cements were bonded to sandblasted hybrid composite, stored at 37 degrees C in 100% humidity overnight, and debonded in tension. Interfacial bond strengths were affected most by the type of pre-bond surface treatment. Hydrofluoric acid produced weaker bond strengths than surface treatment with phosphoric acid. Post-cured Herculite XRV produced weaker bond strengths than the light-cured Herculite XRV. Porcelite cement produced the highest bond strengths. Of the surface enhancers, the acrylic monomer (Special Bond II) produced the highest bond strengths, regardless of which cement or surface preparation was used. Fracture analysis revealed mostly adhesive failures with hydrofluoric acid treatment in both light-cured and post-cured Herculite.
The in vitro bond strengths of three resin cements and a light-cured and a laboratory-processed micro-filled composite were measured. Effects of two surface treatments, and three bond enhancers were analyzed. Resin cements were bonded to sandblasted composite substrates, stored at 37 degrees C in 100% humidity overnight, and debonded in tension. An analysis of variance revealed significant differences among bond strengths. Overall, the composite substrate had the largest effect on bond strength, followed by bond enhancer, cement and, finally, surface treatment. Mean bond strengths ranged from 0.9 to 13.6 MPa. A combination of Concept, Dual Cement, phosphoric acid and Silane produced the lowest mean bond strength (0.9 MPa), while EOS, Dual Cement, hydrofluoric acid, and Heliobond produced the highest recorded mean bond strength (13.6 MPa). In general, the highest bonds were produced using the light-cured composite (EOS), the acrylic monomer (Special Bond II) or the dimethacrylate monomer (Heliobond), the adhesive cement (CR Inlay Cement), and surface treatment with hydrofluoric acid (Comp-Etch). Most of the bond failures (86%) with the laboratory-cured microfilled composite were adhesive. With the light-cured composite, 69% of the failures were mixed adhesive-cohesive types.
Although resin cements have been effectively bonded to mineralized tooth structures, bonding to a cured composite material has remained a challenge. This study evaluated the shear bond strength of a resin cement bonded to a cured composite inlay material by use of a variety of composite surface treatments: (1) hydrofluoric acid/60 seconds, (2) ammonium bifluoride/60 seconds, (3) resin adhesive, (4) microabrasion with 50 microns aluminum oxide, and (5) microabrasion with 50 microns aluminum oxide and application of a resin adhesive. The resin cement was also bonded to human enamel that was etched with phosphoric acid. Scanning electron microscopy examinations were completed to evaluate the effects of the composite surface treatments. The results indicated that microabrasion of a cured composite enhances bonding of a resin cement. The bond strength of a resin cement to a composite surface that was air abraded with aluminum oxide, with or without the application of a resin adhesive, was higher than surface treatments with hydrofluoric acid or ammonium bifluoride. Scanning electron microscopy indicated that an irregular surface on the composite was created with aluminum oxide air abrasion.
To evaluate the use of a silane coupling agent (Silane Bond Enhancer) for repair of a glass-filled hybrid resin composite (Herculite XR).
Composite specimens (n = 20) were either air-abraded (AA) with an intraoral sandblaster (Microetcher), etched with 9.6% hydrofluoric acid (HF) (Porcelain Etch Gel), or treated with both methods (AA/HF). A silane coupling agent was applied to half of the specimens after these initial surface treatments. Composite repairs were completed by application of a phosphonate ester bonding agent (Bondlite) and resin composite (XRV Herculite). Transverse strengths of repaired specimens and intact (control) specimens were determined using an Instron.
The mean bond strengths of repaired specimens ranged from 41% to 62% of the composite's cohesive strength. All repair strengths were significantly lower than the cohesive strength, but were not significantly different from each other. Silanation slightly improved the transverse strength of specimens repaired using the HF and AA/HF methods, but not those repaired using the AA procedure.
Various surface treatments affected the shear bond strength of a dual-cured resin cement to a post-cured composite. Disks of post-cured composite inlay 2.0 mm thick by 10.0 mm in diameter, were mounted in acrylic cylinders. Various surface treatments were tested including: 1) smooth material; 2) treated by sandblasting (air abrasion); 3) sandblasting and etching with hydrofluoric acid (HF); 4) sandblasting and silane priming; 5) sandblasting, HF etching and silane priming; 6) HF etching alone; 7) HF etching and silane priming; and 8) silane priming alone. Specimens of dual-cured cement, 4.0 mm in diameter, were light-cured onto the prepared surfaces. The samples were stored in water at 37 degrees C for 7d before shear bond testing. The highest mean shear bond strengths were achieved for specimens with the following surface treatments: 1) by a combination of sandblasting, HF etching and silane priming; 2) sandblasting and HF etching; and 3) sandblasting and silane priming. Most bond failures in these groups were cohesive within the post-cured composite inlay disks. The bond strengths of the specimen in other groups were significantly lower and bond failures were mainly adhesive at the interface between the disk of post-cured composite and dual-cured resin cement.
Controversy surrounds the use of hydrofluoric acid to prepare precementation surfaces of indirect composites.
This study was conducted to compare effects of combining hydrofluoric or orthophosphoric acid with microetching as precementation treatments.
Nine specimens of three composite materials were prepared to simulate heat-cured indirect restorations. The specimen surfaces were prepared with one of three treatments. Adhesive Bond II and Twinlook cements were used to bond a phosphoric acid-etched disk of P50 to the treated surface. Analysis of variance and Scheffé tests were used to assess the bond strength data. Scanning electron microscopy and microscopic analysis of the fractured and treated surfaces were also performed.
Bond strengths for all surface treatments did not significantly differ. Hybrids had a higher bond strength with etching than microfills, and mechanical roughening produced the greatest bond strengths with microfills. Microetching with orthophosphoric acid produced higher bond strengths than microetching with hydrofluoric acid on hybrids.
Acid etching alone is not sufficient to produce effective bond strengths, and hydrofluoric acid treatments are detrimental to the resin composite.
This study examined the effects of postsilanization interval and heat treatment on shear bond strength of composite resin to porcelain. One hundred and eighty square-shaped specimens were fabricated and sanded flat sequentially. The specimens were then randomly placed into six groups and 18 subgroups of 10 specimens each. An experimental and three commercially available silane systems, including two one-mix and one two-mix systems, were tested in this study. No silane treatment specimen was used as control. Specimens from the experimental and one of the Mirage groups were selected for heat treatment for 60 min at 60 degrees C. Three post-silanization intervals were scheduled. After incubation, a dual cure composite resin (Mirage FLC) was placed on the silanated surfaces and light-cured. All specimens were stored in 37 degrees C, 2% saline solution for 1 week and subjected to shear test using an Instron machine with cross-head speed of 5 mm/min. ANOVA and Scheffe tests were used to analyse data with confidence level at 95%. The mean values of the shear bond strengths ranged from 2.8 to 23.3 MPa. All groups showed significantly higher bond strength than the control group at the 3 min, 24 h and 1 week post-silanization periods (P < 0.05). Heat treatment groups recorded an increase in the shear bond strength and maintained significantly higher bond strength values (P < 0.05). In conclusion, bond strength of composite resin to porcelain resulting from silanization of porcelain increased after heat treatment and during the post-silanization periods. The bond strength also varied for different silane coupling agents tested in this study especially in the one-mix system.
Indirect composite restoratives have been improved in their wear resistance and physical properties. Several new indirect composites claim to be successfully used for full coverage crowns, but there is limited information for wear values of these new indirect composites.
The purpose of this study was to evaluate the wear characteristics of 7 indirect composite restoratives and to compare them with a type III gold alloy by means of an in vitro wear test.
Seven indirect composites (2 photopolymerized and 5 photo/heat-polymerized types) and a type III gold alloy (control) were used. Cylindrical Class I cavities (4-mm diameter and 3-mm depth) were prepared in occlusally flattened extracted human molars. Inlays with respective materials were fabricated on duplicated stone casts according to the manufacturers' instructions. Three types of in vitro wear tests were completed by use of the University of Alabama wear simulator. The wear tests included generalized wear as simulation of the wear during mastication, localized wear as simulation of attrition by occlusal contact, and antagonistic enamel wear, which simulated the wear of enamel created by direct contact with the restorative materials. Seven specimens were tested for each material and wear mode, and the wear depths were measured on profilometric tracings with a 2-dimensional profilometer with 1-microm accuracy. All data were analyzed by 1-way analysis of variance, and multiple comparisons were performed with Fisher's test, for which the significant level was set at.05.
The gold alloy control exhibited a very small amount of wear in both generalized wear (0.2 +/- 0.1 microm) and localized wear (13.8 +/- 5.0 microm) as compared with all composite specimens. The antagonistic enamel wear of gold alloy was similar with the value of Sculpture. The material group, which was post polymerized or post heat-treated, included BelleGlass, Sculpture, Estenia, and Cristobal+ and showed small values ranging from 1.6 to 2.2 microm in the generalized wear. For the localized wear, Estenia exhibited the minimum value (12.8 +/- 4.9 microm) that was statistically the same as the value of the gold alloy control. However, Estenia exhibited the greatest antagonistic enamel wear value (66.0 +/- 14.0 microm) of all materials tested in this study. It was statistically significant with other materials (P</=.05).
Within the limitations of this study, it was concluded that some indirect composite restoratives have similar wear resistance to the type III gold alloy tested. Antagonistic enamel was abraded more by highly filled composite materials.
Recently, new products have been introduced to repair composite restorations that may be used as 'one-step' primers or monomers and silane compounds which are used separately as 'multi-step' primers. The aim of this study was to compare the shear bond strength of the new composite resin to aged composite, by using different adhesion primers.
The substrates were particulate filler composite (Z250, 3M-ESPE), which was aged by boiling for 8 h and storing at 37 degrees C in water for 3 weeks. The aged substrate surfaces were wet-ground flat with 320-grit silicon carbide paper and subjected randomly (n=8) to either one-step adhesion primer: Compoconnect (CC) (Heraus Kulzer), or multi-step: Clearfil Repair (CF) (Kuraray) or an intermediate resin: Scothchbond Multi-purpose adhesive resin (3M-ESPE) according to the manufacturers' recommendations. Specimens with no surface treatment were used as control (C). New composite resin (Z250) was added to the substrate using 2 mm layer increments and light cured. The specimens were either water stored for 48 h or water stored for 24 h and then thermocycled for 6000 cycles. The shear bond strengths were measured with a crosshead speed of 1.0 mm/min using a universal testing machine. Data were analysed by two-way ANOVA and Tukey's post-hoc tests (p=0.05).
All surface treatment methods showed significant difference compared to control (p<0.05). CF showed higher bond strength than CC and MP (p<0.05). Storage condition did not show a significant difference (p>0.05) in bond strength values.
It was concluded that multi-step adhesion primer yielded higher bond strength compared to one-step primer or intermediate resin.
Purpose:
To determine the in vitro bond strength of three laboratory composites repaired with their corresponding direct repair composites using various combinations of surface treatments and primers.
Methods:
The effects of three surface treatments (600-grit as a control, air abrasion with 50-microm Al2O3 particles and 8% hydrofluoric acid etching) and three primers with different formulations [Artglass Liquid (resin/silane), Sculpture Thinning Liquid (resin), and Targis Wetting Agent (silane)] were studied on three laboratory composites (Artglass, Targis and Sculpture). Specimens were stored for 24 hours at 37 degrees C and 100% relative humidity. Tensile bond strengths were determined on an Instron universal testing machine at a crosshead speed of 0.5 mm/minute at room temperature, keeping the specimens moist throughout the testing procedure.
Results:
Three-way analysis of variance (SuperANOVA) indicated that in general, 8% hydrofluoric acid produced the highest bond strengths when used to prepare the three laboratory composites. Either 8% hydrofluoric acid or air abrasion with Al2O3 particles produced the strongest repair bond strengths for Tetric Ceram when used with the resin/silane primer (Artglass Liquid) with values ranging from 36.9 to 39.6 MPa., respectively, as did the combination of hydrofluoric acid and the silane primer (Targis Wetting Agent) 38.2 MPa. The 8% hydrofluoric acid produced the highest bond strengths when used to prepare Artglass and Sculpture and used with the resin/silane primer, 32.9 and 38.7 MPa, respectively. Most bond failures (65%) were adhesive between the laboratory and repair composites, followed by cohesive failures in the laboratory composite with Artglass/Charisma and Targis/Tetric Ceram; and cohesive in the repair composite with Sculpture/Sculpt-It. Overall, the resin/silane primer produced the highest repair bond strengths for Al2O3- and hydrofluoric acid-treated composites.
Clinical significance:
Air abrasion and hydrofluoric acid etching offer acceptable bond strengths for laboratory composites repaired with direct repair composites. Repair bond strengths are enhanced by the application of a resin/silane primer.
To evaluate the repair bond strength of a laboratory processed composite treated with hydrofluoric acid gels of different acid concentrations and for various etching times and repaired with a flowable composite.
75 specimens of a laboratory composite (Targis) were prepared in a split metal mold and stored for 24 hours in an incubator at 37 degrees C and 100% relative humidity. The laboratory composite surfaces were then etched for 5, 10, 15, 30, and 60 seconds using three hydrofluoric acid concentrations (5%, 8%, and 9.5%). The repair composite (Tetric Flow) was light-cured in two increments for 40 seconds each in an inverted, truncated cone mold. Storage conditions of specimens before debonding were 24 hours at 37 degrees C and 100% relative humidity. Tensile bond strengths were determined using a testing machine at a crosshead speed of 0.5 mm/minute. A two-way ANOVA was used to determine significant differences. Failure sites were classified. The morphological aspects of the etched composite surfaces were evaluated qualitatively by scanning electron microscopy.
There were no differences in the repair bond strengths with respect to the three different acid concentrations or the five etching times tested. The minimum etching time to observe an etched pattern was at 60 seconds with the highest concentration of hydrofluoric acid (9.5%).
To measure and compare shear bond strength of three different resin-based composite cements (Panavia 21, Noribond DC, and Variolink II) to two feldspathic ceramic materials (Noritake EX-3 and Ceramco) after 3 days (at baseline) and after 180 days of water storage and repeated thermocycling.
Composite cylinders were bonded with Panavia 21, Noribond DC, and Variolink II to the hydrofluoric acid (HF)-etched surfaces of either Noritake Super Porcelain EX-3 (NEX) or Ceramco (CER) following the manufacturers' directions. Subgroups of 15 specimens were stored in distilled water for either 3 days without thermocycling or 180 days with 12,000 thermal cycles. Shear bond strength was measured and compared by loading each specimen in shear to failure in an Instron testing system. Data were analyzed with a three-factor ANOVA model. Post-hoc multiple comparisons of the individual main-effect levels were performed with Tukey's HSD multiple comparison procedure (alpha = 0.05).
Mean bond strength did not differ for the two ceramic materials. Differences in mean bond strength were found among the bonding systems and between the early and late time points. Panavia exhibited significantly lower bond strength as compared to Noribond and Variolink II for both early and late time points, with a greater difference at 180 days. For all groups, failure modes were almost exclusively cohesive in the ceramic, which indicates sufficient resin-ceramic bonds with all tested materials.
Bonded densely sintered aluminum oxide ceramic restorations such as Procera AllCeram laminates rely on a strong and long-term durable resin bond. Air particle abrasion and a phosphate-modified resin luting agent have the potential to provide such bonds to aluminum oxide ceramics, but their efficacy on the Procera AllCeram intaglio surface is unknown. The inherent microroughness of this surface may influence bond strengths, because micromechanical interlocking is a main contributor for adhesion of resins to ceramic materials.
This study evaluated the bond strength of a phosphate-modified resin luting agent with and without silanization to an air particle-abraded Procera AllCeram intaglio surface compared with a conventional resin-bonding system before and after artificial aging.
Sixty square (10 x 10 x 2 mm) specimens of Procera AllCeram alumina ceramic with the Procera intaglio surface were air particle abraded with aluminum oxide. Composite cylinders (2.9 mm in diameter and 3.0 mm in width) were fabricated with Z-250 composite and bonded to the ceramic specimens with either Panavia 21 TC or Rely X ARC (control) and their corresponding bonding/silane coupling agents. In addition, Panavia was used without silanization as suggested in similar studies. Subgroups of 10 specimens were stored in distilled water for either 3 or 180 days before shear bond strength was tested with a universal testing machine (MPa) until fracture. The 180-day specimens were subjected to thermocycling at 2000 cycles every 30 days (12,000 cycles total). Data were analyzed with 1-way analysis of variance and Tukey's multiple comparison (alpha=.05). Failure modes were examined with a light microscope (original magnification x 25).
Differences between short-term and long-term groups were highly significant (P=.000). Bond strength with Rely X ARC and its silane coupling agent (22.75 +/- 4 MPa) decreased significantly (P=.000) after artificial aging (3.32 +/- 3.62 MPa). Panavia 21 after silanization revealed significantly different (P=.003) early (21.42 +/- 4.3 MPa) and late (16.09 +/- 2.37 MPa) bond strengths but achieved the highest bond strength after artificial aging. Bond strengths of Panavia without silanization both early (8.06 +/- 2.1 MPa) and late (6.91 +/- 2.49 MPa) were not significantly different. Failure modes were mainly adhesive at the ceramic surface for all groups.
Panavia 21 in combination with its corresponding bonding/silane coupling agent can achieve an acceptable resin bond to the air particle-abraded intaglio surface of Procera AllCeram restorations after artificial aging, which had mixed effects on the other investigated groups. The conventional resin luting agent revealed the most dramatic decrease in bond strength.
This study evaluated the repair bond strength of Estenia composite. Disk specimens of a dentin material were conditioned with varying combinations of silane primer (Add-on Primer, Clearfil Porcelain Bond Activator, Clearfil Porcelain Bond Activator + Clearfil Mega Bond-Primer, Porcelain Liner M, and unprimed) and bonding agent (Clearfil Mega Bond-Bond, Modeling Liquid, Stain Diluent, and no bonding agent). After photopolymerization of the enamel material placed on each surface, the specimens were either wet- or dry-stored at 37 degrees C for 24 hours. Average shear bond strength varied from 24.9 to 61.4 MPa, where the Clearfil Porcelain Bond Activator + Clearfil Mega Bond-Bond group and the Add-on Primer + Modeling Liquid group showed the greatest bond strength for dry and wet conditions respectively. To achieve reliable bond strength between layers of Estenia composite, it is highly recommended to use specific combinations of silane primer and bonding agent.
To evaluate the effect of different silane agents and air-drying temperatures on bond strength of translucent quartz fibre posts to composite resin.
The post surface was etched with 10 vol% hydrogen peroxide for 20 min. A two-liquid coupling agent containing 4-methacryolxyethyl trimellitate anhydride (4-META) and gamma-trimethoxysilyil propyl methacrylate (gamma-MPTS) and two pre-hydrolyzed single component silanes containing 3-methacryloxypropyltrimethoxysilane (3-MPS) and glycid-oxi-propyl-trimetil-oxi-silane (GPS), respectively, were used for treating the fiber posts. Two different post-silanization drying temperatures were applied (21 and 38 degrees C). A dual-cure composite resin (Core Paste XP) was selected to build-up the core around posts, obtaining cylindrical specimens that were serially cut in beams and subsequently loaded in tension (muTBS) at a cross-head speed of 1 mm/min until failure. Bond strength data were statistically analyzed by two-way ANOVA and Student-Newman-Keuls tests (alpha=0.05).
Warm air-drying determined significantly higher bond strengths (p<0.001) for glycid-oxi-propyl-trimetil-oxi-silane (11.6 MPa) and 4-methacryolxyethyl trimellitate anhydride/gamma-trimethoxysilyil propyl methacrylate silane (11.7 MPa). These two systems exhibited lower bond strengths (6.9 and 8.8 MPa, respectively) than 3-methacryloxypropyltrimethoxysilane (11.0 MPa) when dried at 21 degrees C. No statistical differences were recorded for 3-methacryloxypropyltrimethoxysilane when drying at 21 or 38 degrees C.
The composition of the silane coupling agent in terms of acidic content, solvent rate or degree of hydrolysis may influence resin/post bond strength when dried at 21 degrees C. Drying at 38 degrees C most likely facilitates the evaporation of solvents present in the silane agent, resulting in increased bond strength of the composite resin to the fiber post.
This study evaluated the effect of two different surface conditioning methods on the repair bond strength of a bis-GMA-adduct/bis-EMA/TEGDMA based resin composite after three aging conditions.
Thirty-six composite resin blocks (Esthet X, Dentsply) were prepared (5 mm x 6 mm x 6 mm) and randomly assigned into three groups for aging process: (a) immersion in citric acid (pH 3.0 at 37 degrees C, 1 week) (CA); (b) boiling in water for 8h (BW) and (c) thermocycling (x5000, 5-55 degrees C, dwell time: 30s) (TC). After aging, the blocks were assigned to one of the following surface conditioning methods: (1) silica coating (30 microm SiO(x)) (CoJet, 3M ESPE)+silane (ESPE-Sil) (CJ), (2) phosphoric acid+adhesive resin (Single Bond, 3M ESPE) (PA). Resin composite (Esthet.X) was bonded to the conditioned substrates incrementally and light polymerized. The experimental groups formed were as follows: Gr1:CA+PA; Gr2:CA+CJ; Gr3:BW+PA; Gr4: BW+CJ; Gr5:TC+PA; Gr6: TC+CJ. The specimens were sectioned in two axes (x and y) with a diamond disc under coolant irrigation in order to obtain non-trimmed bar specimens (sticks, 10 mm x 1 mm x 1 mm) with 1 mm(2) of bonding area. The microtensile test was accomplished in a universal testing machine (crosshead speed: 0.5 mm min(-1)).
The means and standard deviations of bond strength (MPa+/-S.D.) per group were as follows: Gr1: 25.5+/-10.3; Gr2: 46.3+/-10.1; Gr3: 21.7+/-7.1; Gr4: 52.3+/-15.1; Gr5: 16.1+/-5.1; Gr6, 49.6+/-13.5. The silica coated groups showed significantly higher mean bond values after all three aging conditions (p<0.0001) (two-way ANOVA and Tukey tests, alpha=0.05). The interaction effect revealed significant influence of TC aging on both silica coated and acid etched groups compared to the other aging methods (p<0.032). Citric acid was the least aggressive aging medium.
Chairside silica coating and silanization provided higher resin-resin bond strength values compared to acid etching with phosphoric acid followed by adhesive resin applications. Thermocycling the composite substrates resulted in the lowest repair bond strength compared to citric acid challenge or boiling in water.
This study investigated the influence of internal surface treatment and margin location on the microleakage of 2 alumina-reinforced ceramic crown systems: In-Ceram (VITA Zahnfabrik) and Procera (Nobel Biocare). Full crowns were produced for each of the 2 systems (n = 24) in human premolars, with margins located in enamel and dentin, and luted with Single Bond and RelyX ARC (3M ESPE). Four internal ceramic treatments were tested: (1) aluminum oxide blasting (AO), (2) AO plus silane, (3) hydrofluoric acid etching (HF), and (4) HF plus silane. After thermal cycling, leakage was measured quantitatively. Statistical analysis (P < .05) showed higher leakage in dentin margins compared to enamel. In enamel, Procera showed greater leakage compared to In-Ceram. Generally, lower microleakage was observed for the AO plus silane treatment.
The aim of this study is to determine the in vitro two-body contact wear mechanisms of three medium filled composites and compare these with a highly filled composite previously investigated.
Three commercial dental composites with filler mass fraction loading of 75-76% were evaluated. Two of the composites contained Ba-B-Al-silicate glass fillers and fumed silica with different particle sizes and distributions. One of these composites contained a fairly uniform distribution of filler particles ranging in size from 1 to 5 microm, whereas the particle size distribution in the second composite was bimodal consisting of small (less than 1 microm) and large (about 10 microm) particles. The third composite contained Ba-Al-silicate glass and silica with a filler particle size of approximately 1 microm. The composite disks were tested for wear against harder alumina counterfaces. Wear tests were conducted in distilled water using a pin-on-disk tribometer under conditions that represented typical oral conditions (sliding speed of 2.5 mm/s and contact loads ranging from 1 to 20 N). The wear tracks were analyzed by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy to elucidate the wear mechanisms. The chemical composition of the water solution collected after the tests was determined using an inductively coupled plasma-mass spectrometer (ICP-MS) to detect possible chemical changes, e.g. dissolution of trace elements due to submersion or wear. The wear results were compared with those reported in an earlier study on a highly filled composite containing predominately alumino-silicate glass fillers and alumina at a filler loading of 92%.
The differences in two-body wear rates between the three medium filled composites were not statistically significant (p<0.05) indicating that the variations in filler particle size and slight differences in chemical composition of the glass fillers do not affect the in vitro wear rates of these composites. Wear rates of these medium filled composites, however, were significantly lower than the highly filled composite (p<0.05). SEM, FTIR and ICP-MS analyses suggested that wear in the medium filled composites occurs by a complex set of processes involving tribochemical reactions between filler particles and water, formation of surface films containing a mixture of filler fragments and reaction products, and film delamination, as well as dissolution of the reaction products.
This study reveals that subtle changes in the filler particle size and small differences in filler composition do not significantly affect the two-body wear behavior of medium filled composites. However, the chemistry of filler particles plays an important role in altering the wear performance of composites when significant changes are made in the chemical composition of the fillers and when the filler loading is increased.