White spot lesions formed artificially and analysis of their ability to be remineralized: in vitro study

• Grant number: 21/03230-3
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2021
• Effective date (End): July 31, 2022
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal researcher: Marília Afonso Rabelo Buzalaf
• Grantee: Júlia Nochiyma Siqueira
• Home Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

White spot lesion (LMB) can be defined as the primary clinical manifestation of tooth decay, whose milky white, dull clinical appearance is the result of a loss of subsurface mineral structure. Based on the results of previous studies supported by FAPESP, (Process 2018/21944-0 and Process 2018/24904-0) and continuing these studies, the objective of this work will be to develop an in vitro model capable of evaluating the effect of commercial dentifrices in the remineralization of white spot lesions of human enamel produced through the microcosm biofilm. For this will be used 48 specimens of human enamel where the microcosm biofilm model will be used and the analysis of demineralization will be performed. For the formation of the microcosm biofilm, saliva will be collected from 10 healthy individuals who have not brushed their teeth in the last 24 hours and who have not drunk liquids or ingested food in the last 2 hours. Saliva will be diluted (70% saliva and 30% glycerol), and then mixed with McBain's artificial saliva (1:50) to form a cariogenic biofilm for 6 days, for the formation of a shallow enamel lesion. Subsequently, the samples will be divided into 4 groups (A, B, C, D), each group with 12 specimens (A-placebo dentifrice, B- MaxFresh dentifrice 1450ppm F , C - MaxFresh dentifrice 250ppm F, D- Orthogard dentifrice 5000ppm F), these will be submitted to a remineralization protocol for 7 days and during the first 5 days, the specimens will be immersed in demineralizing solution (2.0 mmol / L Ca (NO3) 2.4H2O, 2.0 mmol / L NaH2PO4.2H2O, 0.075 mol / L acetate buffer, 0.04 ppm F, pH 4.7, 15 mL / sample) for 2 h in remineralizing solution (1.5 mmol / L Ca (NO3) 2.4H2O , 0.9 mmol / L NaH2PO4.2H2O, 150 mmol / L KCl, 0.02 mmol / L cacodylate buffer, 0.05 ppm F, pH 7.0, 15 mL / sample) for 22 h (Vieira et al. , 2005). Before and after demineralization, the specimens will be immersed in suspension (1:2) of the test products for 2 min (2 mL/sample). In the last 2 days, the specimens will only be immersed in the remineralizing solution. The nail polishes will be analyzed by TMR. The data obtained will pass through the Kolmogorov and Smirnov and Bartlett tests to verify their normality and homogeneity, respectively. After this verification, the data will be submitted to statistical analysis (p<0.05). (AU)