Forensic dentistry: The key to the truth

Abstract

Introduction Human organism can be identified through testing and analysis of DNA sequences. The most common source of DNA for analysis is blood, soft tissues, hair, bones and teeth. Teeth represent a tissue of choice for analysis in those cases where there is high degree of degradation of other tissues. Hard tooth structure provides protection and preservation of DNA molecules. The aim was to investigate which group of teeth and dental tissue (pulp or hard dental tissues) has the greatest amount of DNA. Material and method Forty-five extracted teeth were analyzed. In the first examination 30 teeth were divided into the three groups (10 teeth each): first group were incisors, second premolars and third molars. The teeth were measured before and after the procedure of DNA isolation using special scale with precision of 0.02-0.000005ng. The procedure included grinding teeth in a blender and DNA isolation using commercial kits (isolation with magnetic particles). For the second test 15 teeth divided into two groups were used. In the first group isolation of DNA molecules was performed from pulp tissue, and in the second group from hard dental tissues. The quantification of samples was done with Quantifiler® Duo DNA Quantification Kit by Applied Biosystems. Results The greatest amount of DNA was obtained from molars (0.230011ng/μl/g) while the smallest amount of DNA was obtained from incisors and it was 0.06437ng/μl/g. In addition, the amount of DNA isolated from pulp tissue was significantly greater than that from hard dental tissues (pulp of molars obtained quantitatively the largest amount of DNA). Conclusion Main tissue to be used for the isolation of DNA from a tooth is pulp, but in those cases when it is not present (endodontic treatment), hard dental tissues provide sufficient quantity of DNA for identification procedures. The group of teeth that provides the greatest amount of DNA is molars.

Keywords

• DNA isolation
• molars
• dento-pulp complex