[Color change in dental tissue as a sign of thermal damage]

The appearance of hard human tissue after thermal damage permits certain conclusions to be drawn with regard to fire parameters. In addition to morphological destruction, the change in color of dental tissues like enamel, dentine, and cement is also important. We studied teeth extracted from 330 human males and females under well-defined time and temperature conditions. Using the DIN and RAL color indexes, the color phenomenon was evaluated on the basis of the amount of glowing obtained when the teeth were heated. It is easiest to determine the color change in cement, as no calculus or hindering plaques are on the root surface. In addition to this, destruction of the tooth root takes place only during extreme combustion conditions. Determining the dentine color is more difficult and is possible only after the enamel splits. Also, the different dentine thicknesses hinders the observation of color. When the enamel was tested, it was found that the differences in color caused by high temperatures are unimportant. Moreover, the enamel burst into small particles. The effect we observed regarding the anthracite lustre using low temperatures was typical, and the best results were obtained in dental roots with eight color scales. All three dental hard tissues have in common that the variations in color appear regularly and successively according to ascending temperature or duration of time: natural dental color, black, brown, blue, grey, white, and pink. In these processes, the temperature and combustion time are inversely proportional to the velocity of color change. The literature is discussed that deals with temperature- and time-dependent color phenomena of dental hard tissues destroyed as a result of thermal damage.