DNA analysis of root canal-filled teeth

Teeth are markedly useful as samples for DNA analysis; however, intact teeth are not always available. This study examined the possibility of identifying autosomal and Y-chromosome short tandem repeat (STR) types in samples from 34 teeth (15 intact and 19 root canal filled) that had been preserved for 10-33years after dental extraction. The aim was to explore the feasibility of individual identification by DNA analysis of samples obtained from highly decomposed and skeletonized corpses. Only one out of 24 autosomal STR loci was not identified in two of the 15 intact teeth, whereas all 23 loci of the Y chromosome STR were detected. One or two autosomal STR loci remained unidentified in eight of the 19 root-filled teeth, and four or five of the 23 Y STR loci were undetected in three cases. However, the types were identified in about 20 loci in all samples, and the composition of the root canal filling material did not appear to interfere with the PCR. This study demonstrates that the storage period of the teeth had no influence on our results indicating that root canal filled teeth can be used for DNA analysis.