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

Abstract

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.