Evaluation of pulp chamber temperature during cementation with the preheated composite resin technique

The cementation technique using preheated composite resin requires high temperatures for optimal execution and may lead to increased and damaging intrapulpal temperatures. Whether the technique can lead to a temperature increase that might lead to necrosis of the pulp tissue is unclear.

The purpose of this in vitro study was to evaluate the temperature variation in the pulp chamber of bovine teeth with veneer-type preparations during veneer cementation using the preheated composite resin technique.

A total of 103 bovine incisors were divided into 8 groups (n=10) and prepared for indirect veneers with different preparation depths: 2.0 mm, 1.5 mm, 1.0 mm, and 0.5 mm. Veneers were cemented on these preparations using 2 cementation protocols: preheated composite resin and photopolymerizable resin cement. The teeth were attached to a device containing a temperature sensor which was inserted into the pulp chamber to quantify the intrapulpal temperature variation produced during the cementation protocols. The data were analyzed using a statistical software program. The level of statistical significance for the analyses was with a confidence interval of 95%, sampling power of 80%, and a moderate effect size (0.36).

The groups cemented with preheated composite resin and the groups with the greatest preparation depth had the highest mean intrapulpal temperature; the PHC2 group presented a mean ±standard deviation temperature increase of 5.70 ±2.14 °C.

The heat generated by heating the resin contributed to the increase in intrapulpal temperature. Temperature variations were greater in deeper preparations, especially when preheated resin technique was used.