Influence of restorative techniques on marginal adaptation and dye penetration around Class V restorations.

The aim of this study was to observe the influence of restorative techniques on marginal adaptation and dye penetration around Class V restorations simulating abfraction lesions. Sixty mandibular premolars were divided into six groups (n = 10) using different restorative materials. Cavity preparation presented the gingival wall localized in dentin and the incisal wall in enamel. Replicas of abfraction lesions were obtained and viewed under a stereomicroscope for adaptation assessment. All teeth were subjected to thermocycling and mechanical load cycling and immersed in 0.5% methylene blue dye (pH 7.2) for four hours. The results were tabulated and submitted to Kruskal-Wallis tests, which were significant for the dentin margin with lower microleakage values for primer/Vitremer, followed by Clearfil SE Bond/Durafill VS and Clearfil SE Bond/Z100 in qualitative and quantitative methods (P < 0.05). The enamel margin had no significant difference for microleakage values for all groups. There was no statistically significant difference among the substrates for marginal adaptation. The Spearman coefficient illustrated a direct relation between enamel and dentin for microleakage evaluation (P < 0.0001). The data demonstrated no difference for marginal fit by chi-square test. It can be concluded that all groups had microleakage in different degrees, with the lowest values for resin-modified glass ionomer.

Assessing microleakage of class V resin composite restorations after Er:YAG laser and bur preparation.

BACKGROUND AND OBJECTIVE: This study aimed to evaluate the extent of microleakage in cavities prepared with bur and Er:YAG laser, hybridized with different bonding systems. STUDY DESIGN: Sixty bovine teeth were randomly divided into six groups (n = 10): (G1) Diamond bur + Single Bond; (G2) Diamond bur + AdheSE; (G3) Diamond bur + Clearfil SE Bond; (G4) Er:YAG (250 mJ, 4 Hz, 80.6 J/cm(2)) + Single Bond; (G5)Er:YAG + AdheSE, and (G6) Er:YAG + Clearfil. Cavities were restored with a micro-hybrid composite resin. After thermocycling, the specimens were stained with 2% methylene blue solution and sectioned in the mesiodistal direction. Dye penetration was scored based upon the extent of the dye using a light stereoscope. RESULTS: The Kruskal-Wallis and Mann-Whitney test revealed no statistically significant differences between the method of preparation (diamond bur and laser). However, statistical differences were found between the adhesives tested. CONCLUSION: Based on the results of this study, Er:YAG laser confirmed to be as effective as the conventional methods for preparing adhesive restorations.