Métodos quantitativos para o estudo do desgaste dentário

Abstract

Tooth wear is an irreversible condition that is common in the clinical routine. The major limitation of studies concerning wear is that these are often based on subjective analysis. The aim of this work is to evaluate tooth wear considering surface information of worn tooth and to propose methodologies to assist in the diagnosis and monitoring of tooth wear. For this purpose, tests with extracted teeth and volunteers with wear using two (2D) and three dimensional (3D) profilomatrical data were performed and surface roughness parameters were selected to discuss mechanisms and evolution of wear in human teeth. For the study with the scanner, scans of teeth with and without wear and an automatic method to estimate the volumetric loss was presented in conjunction with an image evaluation to detect differences in the images performed by two calibrated observers. 2D and 3D profilomoetrical results demostrated that wear does affect the surface without changing its characteristic symmetrical distribution. Not all statistical parameters considered in this study were effective in identifying tooth wear. Mean roghness and root mean squared were inadequate for this purpose. In contrast, both parameters of skewness and kurtosis were able to identify the wear of the teeth and can be useful to explain the clinical features of patients and to identify the surfaces. 2D profiometrical data analysis indicated correlation for the surface parameters and time. This relationship with time for mean roghness and root mean squared were given only to the current moment. To skewness parameter, what happened in the previous first time is more impactful. As for kurtosis, the model that best fitted was a constant model. A general equation for each parameter was obtained. The skewness and kurtosis may have oscillatory variations, tending to a constant rate over a long period of time. The results for this study demonstrated scanner can detect differences directly on the surface of the teeth, avoiding molding marks on physical models. Agreement analysis between examiners of the geometric models showed a good agreement in the assessment of tooth wear, including in the submillimeter range.