Pulp chamber temperature changes during orthodontic bonding – an in vitro study

Abstract

Abstract Aim Using a thermal camera, the aim of the study was to determine pulp chamber temperature changes during orthodontic bonding produced as a result of variations in curing light sources, different curing distances and bracket types. Methods One hundred sixty maxillary premolar teeth were sectioned into two halves and embedded into acrylic moulds. Four curing light sources were used which further divided the overall sample into Halogen, light emitting diode (LED), powered LED, and high-power LED groups. Additional subgroups were created according to the applied curing distances (5 mm, 10 mm) and different bracket types (metallic or ceramic). A standardised bonding procedure was performed and pulp chamber temperature changes were evaluated using a thermal camera. Statistical analysis was performed using a three-way ANOVA. Results The Halogen light curing group revealed a significantly higher temperature rise in the pulp chamber compared to the other groups. A shorter curing distance produced increases in pulpal temperature. There was no significant effect as a result of the bracket type. Conclusions None of the curing light sources exceeded the critical value for pulp chamber temperature rise. The primary desirable outcome was the lowest temperature increase noted with the high-power LED unit. The secondary outcome related to the different brackets revealed no difference relative to pulp chamber temperature change. From a clinical perspective, high-power LED units could be safely used.