Thermographic measurement of temperature change during resin composite polymerization in vivo

Objectives: To use the technique of infrared thermography for non-invasive monitoring of temperature changes during polymerization of resin composite by measuring the infra-red emission from the surfaces of resin composite restorations during photocuring. Methods: In this study 10 patient volunteers had resin composite restorations placed in upper incisor teeth and during photocuring the temperature rise within the composite was measured using the Thermovision 900 infra-red scanning system. Results: The results demonstrate that the exotherm is almost instantaneous, occurring as soon as the light source is activated and rising to a peak at approximately 30 s before levelling off. The measurements suggest that a maximum temperature increase of 12 °C could occur, although this may only be for a short period (<15 s). Conclusion: The range of temperature rise measured in this study (mean 5.4 °C ± 2.5 °C) would suggest that the pulp may be endangered by the temperature rise which occurs during resin composite polymerization in vivo.