Effects of preheated composite on micro leakage-an in-vitro study

Abstract

Introduction: Resin composites have been the pinnacle of direct esthetic restorations ever since its discovery. However, it comes with its own disadvantages. Post-operative sensitivity and marginal discoloration frequently occur due to polymerization shrinkage and micro leakage, which is the major cause of failure in resin composite restorations. Aim: To evaluate the effects of preheated composite at different temperatures on microleakage. Materials and Methods: A total of 60 extracted non-carious human premolars were collected and class 1 cavity (1.5×4 × 3mm) was prepared in each and randomly divided into three groups. Group 1 (n=20) was filled with microhybrid resin composite (Heraeus Charisma Smile) at room temperature. Group 2 (n=20) was filled with the same resin composite which was preheated to 50°C and Group 3 (n=20) was filled with resin composite preheated to 60°C. Teeth were subjected to a thermocycling regime (500X, 5-55°C), followed by a dye infiltration by immersing in basic fuschin for 24 hours. The tooth was sectioned longitudinally and the extent or absence of micro-leakage is determined by the amount of dye penetration along the resin composite-tooth interface using a confocal microscope. Results: There was minor micro-leakage detected at the occlusal margin of the control tooth specimen. The sample with preheated composite restoration at 50°C showed an intact tooth-restoration interface with no micro leakage. However, the preheated composite at 60°C showed large amount of microleakage. Conclusion: Under the current limitation of the study, preheated composite at 50°C shows the least micro-leakage.