Teeth in Fire - Morphologic and Radiographic Alterations: An In Vitro Study

Teeth are the components of the body that often survive severe fires because of their high resistant composition and also because they are protected by the soft and hard tissues of the face. The damage caused by heat can make medico legal identification of human remains difficult in mass disasters associated with fire. The morphologic and radiographic evaluation of dental remains represents a significant aspect in the forensic identification process, particularly after an exposure to fire. Aim: The aim of this ''in vitro'' study was to evaluate the morphologic and radiographic features of teeth after exposure to an experimental range of high temperatures. Methods: A total of 60 extracted permanent teeth were exposed to heat in an Unident digital muffle furnace at five different temperatures (100, 300, 500, 700 and 1000°C). Before and after each exposure, periapical radiographs of all the teeth were taken. The morphologic and radiographic appearances of all the teeth before and after exposure to heat were evaluated and the differences were recorded. Results: The general progression of the colour change from lower temperature to higher was typical light yellow colour, yellowish brown, greyish brown, bluish grey and neutral white. In radiographic evaluation we observed intact teeth at 100°C, a progressive formation of fissures at 300°C and fractures between enamel and dentin at 700°C, large fractures spreading through the dentin and crown crushing at 1000°C. Longitudinal and transverse cracks of root were observed at 1000°C. Conclusion: Morphologic and radiographic alterations caused by incineration may provide useful information about the temperature and duration of exposure to fire. It can also aid in understanding the circumstances surrounding the fire.