Effect of Composite Preheating on Microleakage of Class V Restorations
Objectives: Adapting composite resin to cavity preparation walls can be challenging. Composite Preheating has been shown to enhance its flowability and adaptability. The goal of this study is to evaluate the effect of composite preheating on microleakage in Class V lesions.
Methods: Sixty molars and premolars were prepared with two Class V preparations each, one on the buccal side and one on the lingual side, with occlusal and cervical margins at the enamel and cementum/dentin levels, respectively. The teeth were divided into four groups to be restored with four different brands of nanohybrid composite resin namely, Filtek Supreme Ultra (3M), Herculite (Kerr), Grandio (Voco), and Tetric EvoCeram (Ivoclar Vivadent). Composite resins at various temperatures (room temperature, 40°C, and 60°C) were used to fill the preparations. The samples were stored in distilled water for 24 hours, followed by thermo-cycling between 5°C and 55°C for 2500 cycles. Samples were then placed in 0.5% Fuchsine dye for 24 hours. Finally, the teeth were embedded in self-curing resin and sectioned, to score dye penetration at the occlusal and cervical margins of each restoration, using a 0-3 ordinal scale with a light microscope (×20). The obtained data was analyzed with Kruskal-Wallis test.
Results: A statistically greater amount of microleakage was observed at the cervical margins for all composite brands at all temperatures in comparison with occlusal margins (p<0.05). For all tested materials, preheating treatment had no significant effect on microleakage at occlusal margins (p>0.05). Herculite and Grandio showed a significant decrease in cervical margin microleakage after preheating. The difference between cervical microleakage was not statistically different for Tetric EvoCeram and Filtek at room temperature and preheating treatment.
Conclusions: Within the limitations of this study, it can be concluded that the effect of preheating composite on cervical margin microleakage in class V restoration varies based on composite brands.