Eroded enamel rehardening using two intraoral appliances designs in different times of salivary exposure

• Published in: Journal of clinical and experimental dentistry 2019-12, Vol.11 (12), p.e1127-e1132
• Main Authors: Mendonça, Fernanda-Lyrio, Jordão, Maisa-Camillo, Val, Poliana-Pacífico, de Alencar, Catarina-Ribeiro-Barros, Bassoto, Marcela-de Azevedo-Garcia, Honório, Heitor-Marques, Magalhães, Ana-Carolina, Buzalaf, Marília-Afonso-Rabelo, da Silva, Thiago-Cruvinel, Rios, Daniela
• Format: Article
• Language: English
• ISSN: 1989-5488; 1989-5488
• DOI: 10.4317/JCED.56222

The aim of this study was evaluated the eroded enamel rehardening potential using upper palatal and lower buccal removable appliances in different times of salivary exposure (30 min, 1h, 2h, 12h) after a single erosive challenge event. After initial surface hardness evaluation, bovine enamel blocks were eroded in vitro (0.01 M hydrochloric acid, pH 2.3, 30 seconds), selected (n = 160) and randomly assigned to the two appliance designs and twenty volunteers. Four enamel blocks were inserted in each removable appliance. On the in situ phase, the volunteers were instructed to use the upper palatal and lower buccal appliances simultaneously for 12 nonconsecutive hours. After each predetermined period of time of salivary exposure, the enamel blocks were removed from the appliances for immediate evaluation of surface hardness, enabling percentage of surface hardness recovery calculation (%SHR). The data were analyzed using two-way ANOVA and Tukey's test (α=5%). The results showed no difference in the degree of enamel rehardening by the upper palatal or lower buccal appliances ( >0.0001). Regarding the time of use of the appliances, it was demonstrated that 30 minutes (upper = 21.12%, lower = 19.84%) and 1 hour (upper = 35.69%, lower = 30.50%) promoted lower hardness recovery than two hours (upper = 44.65%, lower 40.80%) of salivary exposure (