In vivo real-time temperature analysis of natural tooth and gold inlay restoration

Abstract

Objectives: Teeth restored with metallic restoration materials have an increase incidence of crack tooth syndrome. One proposed mechanism is that the thermal expansion of dental restoration material exerts harmful effect to the remaining tooth structure. Therefore, the present study analyzed the in-vivo thermal behavior of gold restoration material compared to the natural teeth. Methods: Study sample included eight gold inlay and eight natural teeth from ten volunteers. Customized multi-channel electronic temperature recording device attached to each sample teeth using 3mm thick flowable resin. During the recording period, each volunteer was given 10ml of 58.6°C hot water and 4.42°C cold water for intake. Results: There was no significant difference in resting temperature of natural teeth and gold restored teeth (p>0.05). The maximum temperature after intake of the hot water was higher in gold restored teeth (p<0.05). The intake of the cold water made the temperature of gold restored teeth lower than natural teeth (p<0.05). Analysis of time required reaching the maximum and minimum temperature after each intake showed that the gold restored teeth took less time for maximum heating/cooling than the natural teeth (p<0.05). Overall, the rate of temperature change was higher in gold restored teeth than natural teeth (p<0.05) Conclusions: The modality of temperature change in gold restored teeth and natural teeth was different. Clinical significance: The higher temperature change of intraoral gold inlay compared with natural teeth implies that the gold restoration could be expands more than non-treated natural tooth in the same condition. Therefore, in case of intracoronal gold restoration, careful application of gold is required.