Effect of provisional restorations on the final bond strengths of porcelain laminate veneers
ABSTRACT The purpose of this in vitro study was to evaluate the effect of the different provisional restorations cementation techniques on the final bond strengths of porcelain laminate veneers (PLVs). Thirty-six extracted human central incisors were sectioned 2 mm below the cemento-enamel junction, and crown parts were embedded into self-cure acrylic resin. Standardized PLV preparations were carried out on labial surfaces of the teeth. Then the teeth were randomly divided into three groups of 12 each. In group 1, provisional restorations were cemented with eugenol-free cement. In group 2, prepared teeth surfaces were first coated with a desensitizing agent then provisional restorations were cemented with resin cement. In group 3, provisional restorations were not fabricated to serve as control. After specimens were stored in distilled water for 2 weeks, provisional restorations were removed and final IPS Empress 2 ceramic veneers were bonded with a dual-curing resin. Two microtensile samples from each tooth measuring 1.2 x 1.2 x 5 mm were prepared. These sections were subjected to microtensile testing and failure values were recorded. The data were analysed by one-way anova and Tukey HSD tests. The PLVs, placed on the tooth surface that had received a dentine desensitizer and provisional restorations luted with resin cement (group 2), showed the lowest bond strength in all test groups. But no statistically significant differences were found between the bond strength of PLVs in control group (no provisional restorations) and group 1 (provisional restorations cemented with eugenol-free cement before final cementations). Scanning electron microscopic (SEM) examination of this study also showed that the bonding to enamel surface was better in control group and group 1 than group 2.
- SourceAvailable from: dfd.atauni.edu.tr[Show abstract] [Hide abstract]
ABSTRACT: During fixed prosthodontic treatment, fabrication of temporary restorations to meet the functional, occlusal and esthetic demands of the patients, to protect the tooth and prevent sensit$vity is an important stage of rehabilitation. Successful management of this phase of the treatment can effect the ultimate success of the final restoration and keep the patient comfortable during this short but important period. There are various ways of providing provisional restorations. However, they should be cemented by an appropriate luting cement which owns good mechanical properties and good adhesion to resist bacterial and moleculer penetration.
- [Show abstract] [Hide abstract]
ABSTRACT: This study evaluated the effect of two different types of provisional luting agents (RelyX Temp E, eugenol-based; RelyX Temp NE, eugenol-free) on the shear bond strengths between human dentin and two different resin-based luting systems (RelyXARC-Single Bond and Duo Link-One Step) after cementation with two different techniques (dual bonding and conventional technique). One hundred human molars were trimmed parallel to the original long axis, to expose flat dentin surfaces, and were divided into three groups. After related surface treatments for each specimen, the resin-based luting agent was applied in a silicone cylindrical mold (3.5 x 4 mm), placed on the bonding-agent-treated dentin surfaces and polymerized. In the control group (n = 20), the specimens were further divided into two groups (n = 10), and two different resin-based luting systems were immediately applied following the manufacturer's protocols: RelyX ARC-Single Bond (Group I C) and Duo Link-One Step (Group II C). In the provisionalization group (n = 40), the specimens were further divided into four subgroups of 10 specimens each (Group I N, I E and Group II N, II E). In Groups I N and II N, eugenol-free (RelyX NE), and in groups I E and II E, eugenol-based (RelyX E) provisional luting agents (PLA), were applied on the dentin surface. The dentin surfaces were cleaned with a flour-free pumice, and the resin-based luting systems RelyX ARC (Group I N and E) and Duo Link (Group II N and E) were applied. In the Dual bonding groups (n = 40), the specimens were divided into four subgroups of 10 specimens each (Group I ND, ED and Group II ND, ED). The specimens were treated with Single Bond (Groups I ND and ED) or One Step (Groups II ND and ED). After the dentin bonding agent treatment, RelyX Temp NE was applied to Groups I ND and II ND, and RelyX Temp E was applied to Groups I ED and II ED. The dentin surfaces were then cleaned as described in the provisionalization group, and the resin-based luting systems were applied: RelyX ARC-Single Bond (Group I ND and ED) and Duo Link-One Step (Group II ND and ED). After 1,000 thermal cycles between 5 degrees C and 55 degrees C, shear bond testing was conducted at a crosshead speed of 0.5 mm/minutes. One-way ANOVA, followed by a post hoc Tukey test (alpha = 0.05) was done. The dentin-resin-based luting system interfaces were evaluated under a scanning electron microscope. There was a significant reduction in the mean shear bond strength values of groups subjected to the provisionalization compared to the control and dual bonding technique groups (p < 0.05). The composition of provisional luting did not create a significant difference with regard to reducing shear bond strength values (p > 0.05). With regard to resin based luting systems, the shear bond strength values of the double-bond technique groups were not significantly different from the controls (p > 0.05).Operative Dentistry 01/2007; 32(1):84-93. DOI:10.2341/06-27
- [Show abstract] [Hide abstract]
ABSTRACT: The aim of this study was to evaluate the microtensile bond strengths (MTBSs) of porcelain laminate veneers bonded to normal and fluorosed teeth. Forty human incisors, including 20 normal and 20 moderately fluorosed teeth [Thylstrup Fejerskov Index (TFI) = 4 to 6], were collected. The labial surfaces of the teeth were ground up to 1 mm and polished with #600 silicon carbide abrasive paper. The surfaces were bonded to 1-mm-thick ceramic slices (5 x 5 mm(2)) previously made (VitaVM7) using one of two ceramic cement systems (RelyX or Clapearl) following the manufacturers' instructions. A resin composite was added on top of the ceramic slices and built up to 5-mm thickness to serve as grips. The specimens were stored in water (37 degrees C) for 24 hours, and beams of adhesive interface with a surface area of approximately 1.25 mm(2) were obtained. Then the beams were subjected to MTBS tests at a crosshead speed of 1.0 mm/min. The data were analyzed with two-way ANOVA. The results of the MTBS test (MPa) were 20.55 +/- 5.83 (RelyX/fluorosed), 20.16 +/- 4.61 (RelyX/normal), 18.74 +/- 2.88 (Clapearl/fluorosed), and 21.06 +/- 4.99 (Clapearl/normal). There were no significant differences in the MTBSs among the four groups (p > 0.05). The MTBSs of ceramic cement systems used were not influenced by the moderately fluorosed teeth.Journal of Prosthodontics 12/2008; 18(3):205-10. DOI:10.1111/j.1532-849X.2008.00403.x