Assessing the Validity and Reliability of Tooth Widths and Bolton Ratios Obtained from Digital Models and Plaster Models

AIM: The aim of the study is to compare and evaluate the validity and reliability of tooth widths and Bolton ratios measured from digital models obtained from intraoral scanners and plaster models derived from alginate and polyvinyl siloxane impression materials. MATERIALS AND METHODS: Alginate and polyvinylsiloxane impression was taken for 40 subjects, orthokal stone was poured and grouped as Group I and Group II, respectively. Intraoral scanning was done using Trios Pod 3shape for the same patients, digital models were obtained and grouped as Group III. OrthoAnalyzer software was used for obtaining measurements in digital models and Aerospace Vernier calipers in plaster models. The validity and reliability of the three groups were quantified and compared. RESULTS: Validity measurements showed significant differences between tooth widths and Bolton ratios obtained from digital models and plaster models indicating higher accuracy for plaster models whereas reliability coefficients were excellent for digital models indicating better reproducibility of values. CONCLUSION: The study shows significant differences in accuracy on measuring with vernier calipers and Orthoanalyzer software showing plaster models are still better than digital models for measuring tooth widths and bolton ratios.