Testing a multistage rating scale for clinical evaluation of all-ceramic surfaces

This study tested the applicability of a multistage rating scale based on modified California Dental Association (CDA) criteria and the original criteria of the CDA for surface evaluation of all-ceramic restorations with the use of dental stone replicas, photographs, and scanning electron microscopy (SEM).

Two examiners clinically evaluated 105 all-ceramic restoration units in the posterior region after a mean observation period of 42.2 months; the examiners employed the CDA criteria and a detailed six-stage rating scale. In addition, standardized photographs and gypsum stone and epoxy replicas based on impressions were analyzed blindly using the same rating scales and examiners. SEM images of gold-coated epoxy replicas enabled indirect ceramic surface evaluation, serving as the gold standard to control indirect evaluation and clinical findings. The Cohen kappa was applied to test for concordance; intraclass correlations and Spearman rank correlations were calculated.

Statistically significant rating correlations of the clinical situation, photographs, and stone replicas with the SEM photographs were generated from both evaluation systems. With the use of the multistage rating scale, the highest rating correlation was found for stone replica-SEM (r = 0.61, P < .001), and the lowest for clinical photography-SEM (r = 0.5, P < .001).

A multistage rating scale based on modified CDA criteria is reliable for precise assessment of in vivo ceramic surface alterations. Stone replicas were found to be better-suited than photographs for the assessment of all-ceramic surface alterations and confirmation of clinical ratings.