Microleakage evaluation of photopolymerization efficiency in different layering methods of new generation LED light devices

Background/Aim: The aim of this study was to examine the microleakage values after restoring the prepared Class II box cavities using two different composite resins with three different layering methods and polymerizing them with five different LED light devices. Material and Methods: Class II box cavities were prepared in 150 extracted mandibular molars. Nanoceramic composite resin (Ceram.x SphereTEC one universal A2, Dentsply, Germany) and bulk fill composite resin (SDR flow+ A2, Dentsply, Germany) were used for the restoration of the cavities. Teeth were restored with three different layering methods (bulk fill, horizontal layering, and centripetal buildup technique) and five different LED light devices [(Smartlite Focus, Dentsply, USA), (Led.E, Woodpecker, China), (Valo Cordless, Ultradent, USA), (Bluephase N, Ivoclar Vivadent, Liechtenstein), (D-Light Pro (GC, USA)] and then subjected to microleakage analysis. Kruskal Wallis and Mann Whitney U test were used for statistical analysis. Th e data was evaluated under p<0.005 significant level. Results: Using different layering methods did not affect microleakage scores statistically (p=0.7683). Applying bulk-fill composite resin with 2 mm horizontal layers or using the centripetal buildup technique did not show significant differences in microleakage. Second- and third-generation light devices demonstrated no statistical difference in microleakage (p=0.9075). Conclusions: Using different layering methods and different curing units did not make any difference in microleakage.