Verification of a computer-aided replica technique for evaluating prosthesis adaptation using statistical agreement analysis

J Adv Prosthodont. 2017 Oct;9(5):358-363. doi: 10.4047/jap.2017.9.5.358. Epub 2017 Oct 16.

Abstract

Purpose: The purpose of this study was to evaluate the reliability of computer-aided replica technique (CART) by calculating its agreement with the replica technique (RT), using statistical agreement analysis.

Materials and methods: A prepared metal die and a metal crown were fabricated. The gap between the restoration and abutment was replicated using silicone indicator paste (n = 25). Gap measurements differed in the control (RT) and experimental (CART) groups. In the RT group, the silicone replica was manually sectioned, and the marginal and occlusal gaps were measured using a microscope. In the CART group, the gap was digitized using optical scanning and image superimposition, and the gaps were measured using a software program. The agreement between the measurement techniques was evaluated by using the 95% Bland-Altman limits of agreement and concordance correlation coefficients (CCC). The least acceptable CCC was 0.90.

Results: The RT and CART groups showed linear association, with a strong positive correlation in gap measurements, but without significant differences. The 95% limits of agreement between the paired gap measurements were 3.84% and 7.08% of the mean. The lower 95% confidence limits of CCC were 0.9676 and 0.9188 for the marginal and occlusal gap measurements, respectively, and the values were greater than the allowed limit.

Conclusion: The CART is a reliable digital approach for evaluating the fit accuracy of fixed dental prostheses.

Keywords: Computer-aided replica technique; Concordance correlation coefficient analysis; Prosthesis adaptation; Reliability; Silicone replica technique; Verification.