Dental erosion caused by acid from endogenous origin: effect of reduced calcium content in saliva formulations

• Grant number: 13/27072-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2014
• End date: April 30, 2016
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Cecilia Pedroso Turssi
• Grantee: Giovanna Corrêa Denucci
• Host Institution: Centro de Pesquisas Odontológicas São Leopoldo Mandic. Faculdade São Leopoldo Mandic (SLMANDIC). Sociedade Regional de Ensino e Saúde S/S Ltda (SRES). Campinas , SP, Brazil

Abstract

Bariatric surgery increase the risk of nutritional deficiencies. One of them is hypocalcemia, which occurs in 25 to 50% of the patients. As calcium concentrations in saliva and serum are directly proportional, it has been observed that hypocalcemia can lower calcium secretion in saliva by 80%. Thus, bariatric patients can show reduced calcium content in their saliva. In this regard, it has been demonstrated that a reduction in saturation of saliva with respect to the biological calcium levels reduces remineralization of eroded teeth. Consequently, one can anticipate that hypocalcemia and thereby the reduction in calcium content in saliva might affect dental remineralization after erosive episodes by hydrocloric acid, present in the oral cavity due to vomiting, a common event among post-bariatric surgery patients. In addition, it can be hypothesized that depending on the level of hypocalcemia and thereby on the degree of calcium saturation in saliva, remineralization of dental hard tissues may be more or less affected. Thus, this study is aimed to assess whether saliva formulations with reduced calcium content would affect the magnitude of dental erosion caused by hydrochloric acid. To do so, through a randomized complete block design with a unifatorial scheme, it will be compared artificial salivas with varying contents of calcium. Sixty enamel slabs and 60 root dentin slabs from bovine origin will be embedded, flattened, polished and subjected to baseline Knoop microhardnes measurements and to curvature analysis using an optical profilometer. After reference areas had been created on specimens' surface, they will be exposed to a hydrocloric acid solution (0.01 M; pH 2) for 120 s. Afterwards, specimens will be immersed for 24 h in artificial salivas containing three different calcium concentrations, which simulate conditions of normocalcemia, mild hypocalcemia or severe hypocalcemia in the serum (n = 15). The control group will be immersed in calcium-free artificial saliva. Exposure to hydrochloric acid followed by immersion in one of the saliva formulations will be carried out five times. Wear and final microhardness will be measured. Data will be subjected to parametric or nonparametric statistical approaches, considering the significance level of 5%. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DENUCCI, G. C.; MANTILLA, T. F.; AMARAL, F. L. B.; BASTING, R. T.; FRANCA, F. M. G.; TURSSI, C. P.. Saliva with reduced calcium and phosphorous concentrations: Effect on erosion dental lesions. ORAL DISEASES, v. 24, n. 6, p. 957-963, SEP 2018. (13/27072-1)