Very resistant to fire and chemicals, teeth can sometimes be the only way to identifying remains. Referring to dental records is the first avenue of discovery, but if you cannot find such records a DNA sample from the tooth pulp might aid identification. Make careful note of each tooth: its color, condition and any dental work performed. Check dentures and bridges for and ID stamp from the maker. Prison inmates will sometimes have their inmate identification number stamped on their dental work. Take standard X-rays to illuminate root canal work and other invisible characteristics. Measuring root translucency can determine age after 25 to within approximately 3 years; waer and gum recession can also aid in this process.
information source: www.cbs.com