Aims and objectives: The aims and objectives of our study were to compare four sequential overlays generated using the envelopment technique and to evaluate inter- and intraoperator reliability of the overlays obtained by the envelopment technique.
Materials and methods: Dental stone models were prepared from impressions made from healthy individuals; photographs were taken and computer-assisted overlays were generated. The models were then enveloped in a different-color dental stone. After this, four sequential cuts were made at a thickness of 1mm each. Each sectional cut was photographed and overlays were generated. Thus, 125 overlays were generated and compared.
Results: The scoring was done based on matching accuracy and the data were analyzed. The Kruskal-Wallis one-way analysis of variance (ANOVA) test was used to compare four sequential overlays and Spearman's rank correlation tests were used to evaluate the inter- and intraoperator reliability of the overlays obtained by the envelopment technique.
Conclusion: Through our study, we conclude that the third and fourth cuts were the best among the four cuts and inter- and intraoperator reliability were found to be statistically significant at 5% level that is 95% confidence interval (P < 0.05).
Keywords: Bite marks; computer-assisted overlays; direct cast technique; envelopment technique; forensic dentistry; hollow volume overlays; topographic overlays.