Influence of radiotherapy and chemotherapy in dental caries induction, erosion and abrasion to root dentin of permanent teeth

Abstract

Knowing the changes caused in the oral cavity either by head and neck radiotherapy as for chemotherapy, the aim of this study is to perform an external analysis of the changes undergone by root dentin of permanent teeth of people undergoing radiotherapy and/or chemotherapy; to evaluate, in situ, erosion and caries induction in those teeth; and to evaluate the abrasion resistance of the substrate by brushing. It will be selected extracted teeth from patients who underwent head and neck radiotherapy and chemotherapy treatment at the Hospital das Clínicas de Ribeirão Preto and Hospital do Câncer de Barretos. The selected teeth will be divided into groups according to the antineoplastic treatment they were previously submitted. Each group will have a n = 10, a total of 40 teeth: G1 - control group: teeth extracted from patients prior to performing any type of antineoplastic treatment or healthy; G2 teeth extracted from patients who have completed radiation therapy in head and neck; G3 - extracted teeth of patients who have completed chemotherapy; G4 - teeth extracted from patients who have completed radiotherapy and chemotherapy. 40 root dentin fragments will be randomly distributed among 10 volunteers. The first phase will analyse, in situ, the dental DES/RE process in these substrates the second stage will evaluate, in situ, the tissues´susceptibility to erosion and at the final stage it will be performed the abrasion test by means of brushing test. The quantitative response variables will be wear profile, formed step, dentin tubules count and its perimeters, surface roughness, lost volume and extension of the demineralized tissue. The qualitative variable is the morphological analysis of the surface. The data obtained by quantitative methods will be evaluated normality and homogeneity and are normal and homogeneous will be analyzed statistically with parametric analysis (ANOVA and Tukey-Kramer test) to compare the groups with significance level set at 5% (pe 0.05). Images from confocal and optical microscopy will not be statistically analyzed since the purpose of the analysis is a qualitative comparison of the different experimental conditions proposed in the study. (AU)