Effect of different post-cure polymerization treatment on composite resin hardness

Objective: To evaluate the influence of different additional polymerization methods on the microhardness of two direct composite resins. Methods: Direct Composite resins samples (Fill Magic and Opallis) and a Laboratory Composite Resin (Ceramage) were lightcured according to manufacturer instructions. Then, the direct resins were submitted to additional polymerization. Experimental groups were divided into (n = 5): group 1: Conventional Polymerization; group 2: Extra Light (80s); group 3: Autoclave; group 4: Laboratory Resin Ceramage. Vickers hardness test was carried out after a week of light-free storage in water, and results were subjected to ANOVA / Tukey statistical analysis. Results: Resin Lab Ceramage showed higher astatistically significant microhardness within all other resins in this study (p £ 0.05); Fill Magic showed no statistically significant difference between the groups tested compared to its control (p> 0.05); Opallis resin submitted to autoclave was the only method that showed a higher statistically significant difference compared to the control group (p £ 0.05). Conclusion: It concludes that hardness of a direct composite resin tested - Opallis - was increased by Autoclave post-cure polymerization, however, not enough to achieve the hardness of a laboratory composite. Furthermore, increasing lightcuring time does not produce a harder surface.