Comparative study of the effect of human saliva in vitro and in situ and different formulations of artificial saliva on the remineralization of erosive lesions

• Grant number: 16/13631-7
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2016
• Effective date (End): October 31, 2018
• Field of knowledge: Health Sciences - Dentistry - Pediatric Dentistry
• Principal researcher: Daniela Rios Honório
• Grantee: Isadora Messias Batista Rosa
• Home Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The aim of this study is to evaluate the effect of human saliva in vitro and in situ and different formulations of artificial saliva with or without mucin, on the mineral redeposition on initial erosive lesions. The following groups will be assessed: Artificial saliva 1 (0,33 g KH2PO4; 0,34 g Na2HPO4; 1,27 g KCl; 0,16 g NaSCN; 0,58 g NaCl; 0,17 g CaCl2; 0,16 g NH4Cl; 0,2 g de uréia; 0,03 g de glucose; 0,002 g de ascorbic acid; 2,7 g de mucin em 1000 ml distilled water /pH 7); Artificial saliva 2 (0,1029 g CaCl2 _2H2O; 0,04066 g MgCl2; 0,544 g KH2PO4; 4,766 g Hepes; 2,2365 g KCl em 1000 ml de distilled water / pH 7); Artificial saliva 3 (0,381 g NaCl; 0,213 g CaCl2 _2H2O; 1,114 g KCl; 0,738 g KH2PO4; e 2,2 g de mucin em 1000 ml de distilled water /pH 7); Artificial saliva 4 (2 g methyl-p-hydroxybenzoate; 10 g sodium carboxymethyl cellulose, 0,625 g KCl; 0,059 g MgCl2 _6H2O; 0,166 g CaCl2 _2H2O; 0,804 g K2HPO4 e 0,326 g KH2PO4 em 1000 ml de distilled water /pH 7); Saliva 5 (collected human saliva in vitro); Saliva 6 (in situ human saliva, positive control); deionized water (negative control). The saliva formulations 1 to 5 will be tested with and without mucin, that is, if the original saliva formulation to be tested presents mucin it will be also tested without mucin and if it does not, it will be added 2.7 g / 1000 ml of mucin to the formulation. The initial hardness of enamel specimens from bovine teeth will be measured for selection and randomization of specimens among groups. The specimens will be subjected to an initial erosion challenge in vitro (immersion in 0.05 M citric acid, pH 2.5) for 30 seconds. Thereafter surface hardness will be measured again. Then the specimens will be immersed in the study groups solutions/saliva for two hours. Artificial saliva, collected human saliva and deionized water will be evaluated in vitro and human saliva will be tested in situ with the participation of 10 volunteers who will were palatine intraoral devices. After the two hours, the final surface hardness of the specimens will be measured to calculate the percentage of hardness recovery. The normality and homogeneity of data will be checked and the appropriate statistical test will be applied (parametric or no-parametric). The significance level for all tests will be 5%. (AU)