Histomorphologic and Gravimetric Changes of Teeth Exposed to High Temperature - <i>In vitro</i> Study

Abstract

Background: In forensic dentistry, odontologists have been particularly interested in the investigation of burnt human remains. The purpose of our research is to provide morphological, stereomicroscopic, histological, and gravimetric findings from the investigation of the effects of thermal processes on teeth.Teeth, being the hardest substance in the body, give valuable information for forensic analysis. Objective: Histomorphology and gravimetric changes in teeth exposed to different ranges of high temperatures. Methodology: Thirty-six mandibular premolar teeth extracted for therapeutic purpose were taken and exposed to the varying higher temperatures. Macroscopic, stereomicroscopic, histological analyses along with the dry weight estimation were recorded at each temperature gradient. Results: From a lower temperature to a higher temperature, the specific colour change of the tooth was yellowish-orange, metallic black bronze and chalky white. Stereo microscopically, we observed intact teeth at 100°C; the gradual formation of micro cracks, crown-enamel separations from the cervical margin, eggshell cracking at 500°C; and a completely shattered crown at 900°C. Decalcified sections show dilation in the dentinal tubular pattern at 300°C. Loss of typical architecture was noted at 400°C, with dentinal tubules exhibiting the vapor bubble appearance. In-ground section alterations on the scalloping nature of dentino enamel junction, coalescing radicular dentinal tubules and sand cracking appearance of the tooth were noted at 100°C, 300°C and 900°C, respectively. Significant reductions in the weight of the teeth samples were observed with higher temperatures. Conclusion: Incineration-induced morphologic, histologic, and gravimetric alterations may provide useful information regarding the temperature and duration of fire exposure. It might also assist in understanding the conditions of the fire.