Yavuz Gömeç

Microleakage of repaired class V silorane and nano-hybrid composite restorations after preparation with erbium:yttrium–aluminum–garnet laser and diamond bur

The aim of this in vitro study was to compare the microleakage of repaired class V resin composite restorations prepared either by Er:YAG laser or a diamond bur. Ninety-six intact human molar teeth were randomly distributed into eight groups. In the first four groups, class V cavities (3 × 3 × 3 mm) prepared on the buccal and lingual surfaces of the teeth using an erbium:yttrium-aluminum-garnet laser (VersaWave, HOYA ConBio, Japan). Similar class V cavities were prepared in the second four groups using a diamond bur (S-Class, Komet, UK). Teeth in groups 1, 2, and 5, 6 were restored with a nano-ceramic composite (Ceram.X duo, DENTSPLY), whereas a silorane material (Filtek Silorane, 3M ESPE) was used to restore cavities in groups 3, 4, and 7, 8. Two different adhesive systems (XP Bond, DENTSPLY, and Silorane System Adhesive, 3M ESPE) were also used. All specimens were aged for 7 days. New cavities (3 × 3 × 3 mm) were prepared adjacent to the old restorations with Er:YAG laser (groups I–IV) or diamond bur (groups V–VIII). Different repair materials were then applied to the new cavities using the previous two restorative materials and two adhesive systems. All teeth were subjected to thermocycling (5,000 cycles between 5 and 55°C) and axial loadcycling (30 N, 1 Hz, 2,000 cycles). Specimens were immersed in 50% w/w silver nitrate solution. Teeth were sectioned longitudinally in buccolingual direction. Stereomicroscope (Nikon SMZ 800) and SEM (JEOL JSM 5600) were used to evaluate the microleakage that existed at the interface between the old restorations and the repair materials. Data were analyzed statistically with one-way ANOVA and Tukey tests (p < 0.05). Even though no statistically significant differences were found between any of the groups, the cavities repaired with different restoratives showed slight microleakage, especially those prepared by Er:YAG laser (p > 0.05). No microleakage scores were obtained in the groups repaired with Filtek Silorane/Filtek Silorane and Ceram.X/Ceram.X. All the substances tested can be used as repair materials for immediate repair after Er:YAG laser and diamond bur. All substances tested in this study can be used as immediate repair materials after cavity preparations with Er:YAG laser or diamond bur.

Effect of the erbium:yttrium-aluminum-garnet laser or diamond bur cavity preparation on the marginal microleakage of class V cavities restored with different adhesives and composite systems.

The aim of this in vitro study was to compare the microleakage of Er:YAG laser and diamond bur on different bonding systems in class V restorations. Class V cavities were prepared with Er:YAG laser or diamond bur on 80 intact human molars. Teeth were randomly distributed into ten groups and cavities were restored with CeramX duo (DENTSPLY) or Filtek Silorane (3M/ESPE) using different bonding materials (One Coat 7.0 (Coltène), XP Bond (DENTSPLY), Clearfil Protect Bond (Kuraray), AdperSE (3M/ESPE), and Silorane System Adhesive (3M/ESPE). All specimens were subjected to thermocycling and load cycling. After being immersed in silver nitrate dye, the specimens were sectioned. Microleakage was evaluated by stereomicroscope and SEM. Data were statistically analyzed by one-way ANOVA, Kruskal-Wallis, and Mann–Whitney tests. Statistically differences were found between groups (p > 0.05) and cavities prepared with the Er:YAG laser showed higher microleakage than diamond bur. The microleakage of different bonding systems was influenced by the choice of diamond bur or Er:YAG laser for class V composite cavity preparation.

The effects of halogen and light-emitting diode light curing on the depth of cure and surface microhardness of composite resins

Aim: Light-emitting diode light curing units (LED LCUs) have become more popular than halogen LCUs in routine dental restorative treatment. The aim of the study was to compare the effects of two conventional halogen (Hilux Plus and VIP) and two LED (Elipar FreeLight 2 and Smart Lite) light curing units on the depth of cure and the microhardness of various esthetic restorative materials. Materials and Methods: The curing depth and microhardness of a compomer (Dyract Extra), a resin-modified glass ionomer (Vitremer), a packable composite (Sculpt It), an ormocer (Admira), a hybrid composite (Tetric Ceram), two microhybrid composites (Miris and Clearfil Photo Posterior) and, a nanofil composite (Filtek Supreme) were determined using a scraping method and a hardness tester. A total of 320 samples were prepared using the eight different materials (n = 10 samples for each subgroup). The scraping test was based on ISO 4049:2000. Vickers microhardness testing was carried out using hardness tester (Zwick 3212). Data were analyzed using one-way analysis of variance (ANOVA), Bonferroni and the Kolmogorov–Smirnov tests. Results: Best microhardness results were obtained with the LED light curing units and Tetric EvoCeram and Filtek Supreme achieved the highest hardness values. The nanofil composite, Filtek Supreme, showed the best curing depth results in all the tested light curing systems. Conclusions: The LEDs were found to be more successful than the halogen units with respect to both curing depth and microhardness properties.

Adhesion of conventional and self-adhesive resin cements to indirect resin composite using different surface conditioning methods

Abstract 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.