Degree of conversion of resin cements polymerized under different ceramic systems.

The aim of this study was to evaluate the degree of conversion of resin cements polymerized under different ceramic systems. Forty specimens of RelyX ARC (3M ESPE) and Maxcem Elite (Kerr) resin cements were polymerized under 5 types of dental ceramics: feldspathic, aluminum oxide-reinforced, aluminum oxide-based strengthened with zirconium oxide, leucite-reinforced, and lithium disilicate-reinforced. Measurements of the degree of conversion of the resin cements were performed 10 minutes, 1 hour, and 24 hours after curing using a Fourier transform infrared spectrophotometer. The values were subjected to a 3-way repeated-measures analysis of variance, and the means were compared with the Fisher protected least significant difference test (α = 0.05). The study findings showed that RelyX ARC resin cement displayed a higher degree of conversion than Maxcem Elite (P < 0.05). The degree of conversion was significantly lower for RelyX ARC polymerized under aluminum oxide ceramic and aluminum oxide ceramic strengthened with zirconium oxide (P < 0.05). For Maxcem Elite, there was no significant difference in the degree of conversion attained under the various ceramics (P > 0.05). For both cements, the degree of conversion increased gradually up to 24 hours after curing (P < 0.05). The ceramic system used directly influenced the degree of conversion of RelyX ARC. Both resin cements displayed an increase in the degree of conversion over time.