Time-dependent changes in DNA stability in decomposing teeth over 18 months.

Objective: The objective was to use a dual quantitative and qualitative approach to analyze the dental DNA degradation produced by the passage of time since tooth death under controlled environmental conditions.

Materials And Methods: Sixty human teeth were stored at room temperature for 0, 1, 3, 6, 12 or 18 months post-extraction. DNA quantification was determined by real-time quantitative PCR using a Quantifiler(TM) kit. DNA quality was assessed by the allelic dropout ratio between the smallest and largest loci obtained after STR genotyping and using an AmpFlSTR® Identifiler™ PCR kit. We also evaluated differences of DNA concentration related to gender and tooth position.

Results: DNA concentration significantly reduced in 1 month post-extraction, stabilized between 1-12 months post-extraction, but decreased again at 18 months post-extraction. Interestingly, a significant reduction of the allelic dropout ratio (DNA quality) was only detected at 18 months post-extraction.

Conclusions: Stability of dental DNA decreased over time, differently affecting the amount and quality of the DNA in a time-dependent process over the first 18 months post-extraction. These results have a potential use in post-mortem intervals in human teeth in controlled environmental conditions.