Abstract
The nature of crime is changing day by day and the forensic scientists are always facing new problems in human identification. The practice of destroying human body by immersing in an acid is drawing a great deal of forensic interest these days. The present study aimed to identify the acid that is most likely used in such crimes and to determine if the morphological changes in teeth and different restorative materials could predict the approximate duration of time elapsed after immersion of a body in an acid. 240 teeth with and without different restorations were immersed separately in 3 different acids and were observed for morphological changes over a period of 30 days. Teeth dissolved completely in hydrochloric acid (HCl) and nitric acid (HNO3) by 48 hrs and 20 hrs respectively. Teeth showed precipitation in sulphuric acid (H2SO4) with only remnants of white precipitate by the end of 288 hrs. Amalgam restorations in HCl did not show any changes. They exhibited blackish discoloration on the surface when placed in H2SO4, but in HNO3, they settled as silver powder with the release of brown fumes. Composite restorations in HCl and HNO3 did not demonstrate considerable morphological changes. In H2SO4, they showed surface discoloration and softening. Glass ionomer cement (GIC) in HCl and HNO3 dissolved completely. In H2SO4 they settled as white precipitate. When a human body is destroyed using acids, teeth or restorative materials retrieved can serve as an effective tool in crime investigations and can help the investigator to deduce the time elapsed since the commitment of crime.