Reliability of qualitative occlusal tooth wear evaluation using an intraoral scanner: A pilot study

Abstract

Dental wear analysis through the use of an intraoral scanner is a reality of modern dentistry. This study aimed to investigate the reliability of qualitative tooth wear evaluation through three-dimensional images captured with an intraoral scanner and compared to clinical and photographic examinations. Eighteen adult volunteers of both genders (18 to 55 years old) were submitted to clinical exams, intraoral photographs and intraoral scanning protocol using an optical scanner (TRIOS® Pod, 3Shape, Copenhagen, Denmark). Occlusal tooth wear, from second to second premolars, was measured by two evaluators and reevaluated after 30 days, according to a slight modification of the method described by Mockers et al. Weighted Kappa was used to measure intra and inter-examiner agreement. The Friedman test was used to verify the differences among methods. Random and systematic errors were assessed using Bland-Altman plots. All statistical analysis was performed with p<0.05. There was a substantive agreement for clinical (K = 0.75) and photographic exams (K = 0.79) and a moderate agreement for intraoral scanner analysis (K = 0.60) for inter-examiner evaluation. A substantial intra-examiner agreement was obtained for both evaluators. No significant difference between the methods was observed (p = 0.7343 for examiner 1 and 0.8007 for examiner 2). The Bland-Altman plot confirmed no systematic errors between the methods and a random error of 0.25 with the scanner method when compared to clinical assessment. All three methods showed reliability in qualitative occlusal tooth wear evaluation. Intraoral scanning seems to be a sound and reliable tool to evaluate tooth wear when compared to traditional methods, considering the lower inter-examiner agreement and the inherent limitations of this pilot study. Further research will be necessary in order to achieve more robust evidence.

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. Patient 1 (P1), patient 2 (P2), and patient 3 (P3) occlusal intraoral photographs and 3D images captured with the intraoral scanner of a modified tooth wear measurement performed by the same operator.

A- upper dental arch photo; B- lower dental arch photo; C- upper dental arch scan; D- lower dental arch scan. Scores: 0- absence of wear; 1- enamel wear only; 2- dentin wear, with the occlusal/incisal face showing more enamel than dentin; 3- dentin wear, with the occlusal/incisal face showing more dentin than enamel; 4- advanced wear stage, near or beyond the pulp.

Fig 2. Bland-Altman test comparison between A- the clinical exam and intraoral photography and B- the clinical exam and intraoral scanner.

From the visualization of the dispersion graph, displays low variability and a significant concordance between the methods, with no large dispersions or outliers.