Ex Vivo Evaluation of the Erosive Potential of Typical Fruit Juices from Brazilian Tropical Forests

Introduction: Dental erosion is defined as an irreversible loss of hard tissue caused by intrinsic and extrinsic acidic sources, non-bacterial dissolution not directly associated with traumatic factors or tooth decay. Aim: The aim of this study was to analyse the ex vivo pH, titratable acidity and erosive potential of following juices: Theobroma grandiflorum, Annona muricata, Spondias mombin and Spondias tuberosa, which are commonly found and widely used fruits by the population of the northern and north-eastern regions of Brazil. Materials and Methods: Fifteen human third molars, extracted for clinical reasons and obtained from Human Teeth Bank of the Dental School (Federal University of Juiz de Fora), were selected to be immersed in the juices and in 1% citric acid (positive control group) and perform erosive cycles. The samples were immersed in the solutions for 2 minute, five times a day, at intervals of two hour, for four days. Between the erosive cycles, the specimens remained in artificial saliva. Before the beginning of the erosion cycles and at the end of the cycle sequence, specimens were analysed for roughness and for microhardness. Statistical analyses were performed using the IBM SPSS Statistics 22.0 software. The results were expressed as a mean +/- standard error of the mean, and analysed using variance analysis (ANOVA), followed by post-hoc Tukey's test. The significance accepted was p<0.05. Results: The pH of all juices analysed was acidic, within a narrow range of pH values from 2.41 to 3.28 and titratable acidity values suggest that the beverages tested have pH lower than the critical pH for dental enamel. Conclusion: The data analysis allows one to conclude that all the juices presented acid pH and promoted significant loss of superficial enamel hardness. Regarding the surface roughness of the samples from this study. only 1% citric acid and the juice of Theobroma grandiflorum reached values close to or greater than the critical surface roughness. Therefore, one must be aware of the great erosive potential of these juices when drinking them.