In vitro evaluation of artificially formed white spot lesions and analysis of their ability to be remineralised

• Grant number: 18/24904-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): February 01, 2019
• Effective date (End): January 31, 2020
• Field of knowledge: Health Sciences - Dentistry - Pediatric Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: Helena Richieri Falcão Tuler
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The white spot lesion (WSL) can be defined as the primary clinical manifestation of dental caries, whose milky white appearance without dullness results from the loss of subsurface mineral structure. Based on this, the objective of this work will be to develop in vitro reproducible white spot lesions (WSL) with different levels of mineral loss using a microcosm biofilm model in human enamel samples and characterize them by microregion demineralization analysis (TMR), quantitative light-induced fluorescence (QLF) analysis and spectrophotometry (EasyShade), B) Develop an in vitro model capable of comparing two different types of carious lesions at the same time using technologies with different characteristics with respect to color, fluorescence and mineral content through the analysis by TMR, QLF and spectrophotometry (Easy shade). For phase A will be used 90 human enamel specimens where the microcosm biofilm model will be used and the demineralization analysis will be performed. In phase B, an in vitro study will be carried out using 60 enamel samples and will be selected by the surface microhardness (initial SMH) and in the sequence will be submitted to the production of artificial caries lesion from the groups to be defined. The samples will be submitted to a remineralization protocol for 7 days and during the first 5 days, each day 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 and in remineralizing solution (1.5 mmol / L Ca (NO 3) 2.4H 2 O, 10 mmol / L NaH2 PO4.2H2O, 150 mmol / L KCl, 0.02 mol / L cacodylate buffer, 0.05 ppm F, pH 7.0, 15 mL / sample) for 22 h (Vieira et al., 2005) . Before and after demineralization, specimens will be immersed in suspension (1: 3) of the test product for 1 min (15 mL / sample). In the last 2 days, the specimens will be immersed only in the remineralizing solution. The enamels will be analyzed by TMR, QLF and Easyshade. 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).