Influence of application frequency of AmF/NaF/SnCl2 solution in its potential in inhibiting the progression of erosion in human dental enamel

Author(s)

Camila Vieira da Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia (FO/SDO)
• Defense date: 2015-11-03

Examining board members

Patricia Moreira de Freitas Costa e Silva; Alessandra Buhler Borges; Taís Scaramucci Forlin

• Advisor: Patricia Moreira de Freitas Costa e Silva

Abstract

Although several studies have shown promising results using the AmF/NaF /SnCl2 solution in inhibiting the progression of dental erosion, measures to further improve its effectiveness are fundamental. Thus, this in vitro and in situ study aimed to evaluate if the protective effect of this solution can be enhanced by increasing the frequency of use. Human enamel samples were obtained from sound human third molars; sixty for the in vitro study (4 x 4 x 1 mm), and ninety-six for the in situ (3 X 3 X 1 mm) study. After the formation of incipient erosive lesions, the in vitro samples (1% citric acid, pH 4.0, for 3 minutes), were divided into 5 treatment groups (n = 12): G1 - distilled water (negative control); G2 - NaF solution (positive control) 1x/day; G3 - NaF solution (positive control) 2x/day; G4 - AmF/NaF/SnCl2 solution 1x/day; G5 - AmF/NaF/SnCl2 solution 2x/day. The samples were then subjected to 5 days of erosive cycling through 6 daily immersions (2 minutes each) in citric acid solution (0.05 M, pH 2.6). At the end of erosive cycling, surface wear was determined by means of optical profilometry. To perform the in situ erosive challenge, the samples were also subjected to the formation of incipient lesion with the same methodology of the in vitro study. Twelve volunteers participated in the crossover in situ study - divided into four phases of 5 days each - and used a unilateral lower removable device containing 2 samples of eroded human enamel, which were changed at each phase. The samples were divided into 4 treatment groups (n = 12), the same considered for the in vitro phase, with the exception of the group of NaF solution 2x/day. During the in situ experimental phase, the device containing the sample was subjected to the erosive cycling (ex vivo), similar to the in vitro phase. At the end of each in situ experimental phase, the samples were removed from the device and analyzed by profilometry, and the average of duplicate samples were considered for statistical analysis. The ANOVA showed that the surface wear was affected by treatments evaluated in both in vitro and in situ (p?0,001) studies. In the in vitro study, the Tukey test showed no difference between the application of groups of NaF 1 (16.21 ±1.47) or 2 times (15.39 ±1.01), which showed limited reduction in wear compared to the distilled water group (20.36 ±1.56). Among the groups of AmF/NaF/SnCl2 solution, there was no difference between 1 (10.40 ±2.36) and 2 application times (7.27 ±3.29), and, although both demonstrated significantly reduced tissue loss, increasing the frequency has increased its anti-erosive potential. In the in situ phase, the NaF solution did not reveal the ability to reduce surface wear, and although there was no significant difference between the AmF/NaF/SnCl2 1 (2.64 ±1.55) and 2 times groups (1.34 ±1.16), this solution was effective in reducing the erosive wear compared to groups NaF (4.59 ±2.75) and distilled water (4.55 ±2.75). The AmF/NaF/SnCl2 solution shown to be effective in protecting the enamel progression of dental erosion, and increasing the frequency potentiate its anti-erosive effect both in vitro and in situ. (AU)

• FAPESP's process: 14/10955-0 - In situ evaluation of the SnF2 potential in inhibiting the progression of the erosion process on human dental enamel
• Grantee: Camila Vieira da Silva
• Support Opportunities: Scholarships in Brazil - Master