Influence of Different Ceramic Systems on the Polymerization of Dual-cured Resin Cement evaluated Immediately and after 24 Hours: An in vitro Study

Abstract

ABSTRACT Background To check the influence of different all-ceramic systems on the polymerization of a dual-cured resin cement, evaluated immediately and 24 hours after curing cycle. Materials and methods A total of 80 resin cement disk specimens (n = 20) were fabricated by polymerization through lithium disilicate disks (group B), leucite-reinforced disks (group C), zirconia disks (group D) and without an intervening ceramic disk (group A). Each group further consisted of two subgroups (n = 10), t30 and t60 according to two different exposure times of 30 and 60 seconds respectively. Each of the 80 resin disk specimens was evaluated for microhardness (VHN) immediately and after 24 hours, giving us a total of 160 readings. One way analysis of variance (ANOVA) test was used for multiple group comparisons followed by Tukey's post-hoc for group-wise comparisons. Results Direct activation (group A) of the resin cement showed statistically significant higher mean microhardness values as compared to the experimental groups (groups B, C and D), both immediately and after 24 hours. The mean microhardness for immediate postactivation was always inferior to the 24 hours postactivation test for both direct activation and through different ceramics. For immediate testing time, of both the 30 and 60 seconds curing cycle, there was a significant increase in the microhardness of the resin cement disks cured for 60 seconds through the different ceramics (groups B, C and D) and direct light activation (group A). For the 24 hours testing time, of both the 30 and 60 seconds curing cycle, there was a significant increase in the microhardness of the resin cement disks cured for 60 seconds through the different ceramics except for the direct light-activation group. Conclusion Ceramic composition affected the polymerization of dual-cured resin cements. Doubling the light irradiation time significantly increased mean microhardness value. Greater degree of conversion leading to an increase in hardness was observed when the resin cement disks were evaluated after 24 hours. How to cite this article Jain NV, Dugal R, Madanshetty P, Poplai GR, Gharatkar AA, Shinde PH. Influence of Different Ceramic Systems on the Polymerization of Dual-cured Resin Cement evaluated Immediately and after 24 Hours. An in vitro Study. Int J Prosthodont Restor Dent 2015;5(1):1-9.