Effect of pre-heating composite resin on gap formation at three different temperatures

AIM: The study aims to evaluate and compare total gap surface area formed after restoration of class II cavities with Filtek Z350 and P60 at room temperature, 37°C and 54°C. MATERIALS AND METHODS: Thirty extracted maxillary and mandibular molars were taken and divided into six groups of five teeth each. Standardized class II cavities were made and were restored with Filtek Z350 and P60, both at room temperature, 37°C and 54°C. Group 1(a) was restored with Filtek Z350 at room temperature, Group 1(b) with Filtek Z350 at 37°C and Group 1(c) with Filtek Z350 at 54°C. Group 2(a) was restored with P60 at room temperature, Group 2(b) with P60 at 37°C and Group 2(c) with P60 at 54°C. After storing the samples in distilled water at room temperature for 48 hours, longitudinal sectioning was done to obtain tooth restoration interface. The interfaces were then examined under compound light microscope with digital output and analyzed using Image J analysis software. RESULTS: The results demonstrated better adaptation and less total gap area formation at 54°C as compared to room temperature and 37°C. CONCLUSIONS: Based on the results of this study, it is suggested that use of P60 is better suited for posterior restorations at 54°C as compared to Filtek Z350 universal nanohybrid at room temperature.