Effect of preheating on the cytotoxicity of bulk-fill composite resins

Abstract

Background . Due to the effect of pre-heating on the degree of conversion of composite resins and the possible effect on cytotoxicity, the effect of pre-heating of bulk-fill composite resins was investigated on cytotoxicity in this study. Methods. In this study, three different types of composite resin were used, including Tetric N-Ceram Bulk-Fil, Xtrafil, and Xtrabase. From each composite resin, 10 cylindrical samples (5 mm in diameter and 4 mm in height) were prepared, with five samples preheated to 68°C, and the other five samples polymerized at room temperature (25°C). Twenty-four hours after polymerization, cytotoxicity was assessed by MTT assay on human fibroblasts. Statistical analysis of data was carried out with two-way ANOVA and Sidak Post-Hoc. The significance level of the test was determined at 0.05. Results. There was no statistically significant difference between the mean percentage of cytotoxicity in terms of pre-heating (P>0.05), but the cytotoxicity of the studied composite resins was significantly different (P<0.001). The cytotoxicity of Tetric N-Ceram Bulk-fil composite resin was higher than that of the two other composite resins. Conclusion. Pre-heating of bulk-fill composite resin did not affect their cytotoxicity. In addition, the cytotoxicity of different bulk-fill composite resins was not the same.

Does Preheating Influence the Cytotoxic Potential of Dental Resin Composites?

“…Based on the unanimous findings of all three cytotoxicity tests, the general linear model and partial eta-squared statistics revealed an insignificant effect of preheating. Similar to our results, negligible effect of preheating was observed in other studies also, in contrast to the effect of the type of RBCs which resulted in expressed differences in cell viability [ 20 , 37 ]. Undesirable effects are attributed to monomers, which are a significant component of RBCs as they represent about 20–40% of their content.…”

“…By investigating the in vitro biocompatibility of preheated microfilled-hybrid RBCs, it was detected that the combination of composition, pre-polymerization temperature, curing time and polymerization pattern has a stronger effect on cytotoxicity of the RBC than the pre-polymerization temperature alone [ 19 ]. The results conducted on bulk-fill RBCs revealed no significant differences on cell viability with or without preheating, however showed the effect of RBC’s composition to be significant [ 20 ].…”

Two-year clinical performance and marginal integrity evaluation of high C-factor occlusal cavities restored with preheated Bulk-Fill, SonicFill and incremental fill composite resin

“…Several physical properties were also improved due to pre-heating as higher flexural, diametral tensile strength and surface hardness [40] . There are many previous studies who evaluated the effect of preheating of composite resins [6,[41][42][43][44] . Despite the significant results of the former in-vitro studies, clinical evaluation and follow up are essential to expect the durability and longevity of a restorative material in the multifactorial and challenged oral conditions.…”

Effect of Rapid High-Intensity Light-Curing on Increasing Transdentinal Temperature and Cell Viability: An In Vitro Study

“…Forty sound, human molars, without cavities, restorations, cracks, fissures, or fractures, were selected for this research. The sample size was determined based on previous experiments with similar characteristics and outcomes, regarding the increase in temperature during light-curing [ 21 , 22 , 23 , 24 ] and cell viability analysis [ 25 , 26 , 27 ]. The recommendation from the risk of bias (RoB) tool for laboratory studies on dental materials [ 28 ] was followed.…”