Effect of desensitizing treatments in the evolution of erosive lesions on dentin

Author(s)

Júlia Olien Sanches

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC)
• Defense date: 2017-02-17

Examining board members

Regina Guenka Palma Dibb; Silvia Lustosa de Castro; Milton Carlos Kuga; Cesar Penazzo Lepri; Marcelo Oliveira Mazzetto

• Advisor: Regina Guenka Palma Dibb

Abstract

The in vitro study evaluated the desensitizing agents in the evolution of the erosive process on root dentin and the in vivo study evaluated the desensitizing treatment in the progression of the erosive lesions and in the dentin hypersensitivity (DH). 90 specimens of root dentin were immersed in 6% citric acid (initial erosion) and they were observed through the Confocal Laser Scanning Microscopy (CLM) (initial evaluation). The half their buccal surface was covered (control area). The specimens were randomly divided into 6 groups (n=15): G1(no treatment); G2(Oxagel); G3(Desensibilize Nano P); G4(MI Paste); G5(experimental paste); G6(970-nm diode laser-0.7W/10Hz, 70mJ). After that, they were cycled through erosive challenge (0.3% citric acid, 9-days). The treatments were applied every 3 days. The evaluations of the wear profile, roughness, step and the volume loss of treated area were carried out by the CLM at different times of the erosive challenge. After control area exposure, the final analysis was performed on the 9th day. The permeability test was performed at the end of the experiment (optical microscopy). For superficial analysis, the treatments were compared by ANOVA and the time factor was analyzed by the Friedman and Tukeys Tests (α=5%). For the morphological and dentin permeability analysis, ANOVA and Tukey\'s Test (α= 5%) were performed. For the clinical study, 20 patients were selected with erosive cervical lesions in two different quadrants and they were randomly divided into two groups: control group (placebo agent) and treated group (Desensibilize Nano P). Four treatment sessions (7 days interval) and 3 post-treatment follow-up sessions (1, 3 and 6 months) were performed. For the progression analysis of the lesions, replicas were obtained by molding them at each session and evaluated by the MCL. The DH evaluation was performed through the application of air jet in the lesion and by the numerical rating scale. The analysis of variance, the Friedman, Kruskall-Wallis and Tukeys Tests was performed (α=5%). For DH analysis, data were submitted to the non-parametric Wilcoxons Test (α=5%). In vitro evaluation of the wear: significant difference was observed in all response variables; G3 showed the lowest values for step and volume loss. Morphological analysis: G5 showed the lowest number and area of exposed tubules during the cycling. Dentin permeability: G3 showed the highest values and G5 exhibited the lowest values; the other groups were similar to each other and to G3 and G5. Clinical evaluation of the wear: there was 18 19 no significant difference between the groups. Regarding lesion dimension, there was no difference, but comparing the initial and final values, there was a similar increase in both groups. DH: there was no significant difference between the groups, only between the initial and final. In vitro, Desensililize Nano P was able to control the erosive process and the experimental paste showed positive results on dentin tubule occlusion and dentin permeability. Clinically, Desensililize Nano P was not able to control the progression of erosive lesions and demonstrated positive results for the treatment of DH. (AU)

• FAPESP's process: 13/02450-3 - Effect of desensitizing treatments on development of erosive lesions on dentin
• Grantee: Júlia Olien Sanches
• Support Opportunities: Scholarships in Brazil - Doctorate