Influence of indirect air-cooling on the variation in intrapulpal temperature during rapid high-intensity light-curing using a bulk-fill resin composite.

Abstract

Background: This study investigated the effect of indirect air-cooling on the variation in intrapulpal temperature (ΔT) during different light-curing protocols of bulk-fill resin composites in molars with class V cavities.

Material and methods: A nonretentive class V cavity was prepared in a maxillary molar. The intrapulpal temperature changes with and without indirect air-cooling were recorded using a type K thermocouple. The cavity was restored with bulk-fill resin composites: Tetric PowerFlow (Ivoclar, Vivadent) and Filtek Bulk-Fill Flow (3 M, ESPE). The tooth was exposed to different light-curing protocols (n=5) using the Valo Grand light-curing unit: (i) high-intensity light-curing protocol of 3200 mW/cm² (3 and 6 s) and (ii) moderate-intensity light-curing protocol of 1000 mW/cm² (10 and 20 s). The ΔT data were subjected to two-way ANOVA, followed by the Bonferroni post hoc test.

Results: A significant increase in temperature was observed with the use of the high-intensity light-curing resin composite without indirect air-cooling. In addition, the application of air-cooling significantly decreased the temperature in all the groups except for the Tetric PowerFlow bulk-fill resin composite at 3 s of light-curing.

Conclusions: Indirect air-cooling resulted in a lower increase in intrapulpal temperature during the light-curing of bulk-fill resin composites, making it an effective alternative technique for controlling the temperature rise in class V restorations with 1 mm of remaining dentin. Key words:Dental curing lights, dental pulp, temperature, resin composite.