Effect of Pre-Heating on Resin Composites' Polymerization Depth

Abstract

Aim: The aim of this study was to evaluate the effect of pre-heating on depth of cure of different composite resins. Materials & Methods: In the current study one methacrylate and one silorane-based composite were evaluated. In the first group the specimens were stored in refrigerator at 4°C and the second group were kept in room temperature at 23°C for an hour. In the other groups a composite warmer (Micerium, S.p.a., Avegno GE, Italy) were used for heating the tubes up to 37°C and 55°C. Disk shaped specimens of composite resins with different temperatures were prepared in a teflon mold with a diameter of 4 mm and a depth of 8 mm (n=5). The specimens were light cured for 40 s with a quarts tungsten halogen curing unit. Immediatly after irridation, uncured material was scraped away with a spatula. The height of the cylinder of set resin was measured with a digital micrometer and the half of this value was recorded as depth of cure value. Each sample was measured three times and the mean values were recorded. Data were statistically analyzed with one-way ANOVA and Tukey tests. Results: The difference between the different composite resins at the same temperature was not statistically significant(p>0,05). Intragroup comparisons showed that pre-heating the methacrylate-based composite did not effected the depth of cure(p>0,05). The highest depth of cure value for silorane based composite was obtained at 4°C, and the lowest at 23°C, and the difference was statistically significant(p<0,05). Conclusion: The effect of pre-heating on depth of cure is materyal depended.