Validation of a pH-cycling model to estimate the potential of fluoridated products on the reduction of demineralization of enamel of deciduous teeth

• Grant number: 13/15251-9
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2014
• End date: April 30, 2016
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Cinthia Pereira Machado Tabchoury
• Grantee: Cinthia Pereira Machado Tabchoury
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Since the enamel of primary teeth is more susceptible to decay than the permanent laboratory models have been used to evaluate the effect of substances capable of controlling caries in primary teeth should consider this difference, which has not been observed in the literature consulted. The objective of this project will validate a pH cycling model for the study of demineralization of the enamel of deciduous teeth, evaluating the dose-response effect of fluoride. Initially from enamel powder (particles 74-105 mM) of primary teeth will be prepared a 50% saturated solution in acetate buffer 0.05 M pH 5.0 and the calcium, fluoride and phosphorous in this solution will be determined . Dental blocks (3 x 3 x 2 mm) obtained from healthy primary teeth will be used and an enamel layer of the central part of the block is removed, flattened and polished. The initial surface hardness of the specimens is determined for selection of the same and for calculating the surface hardness loss after cycling and pH treatments. For this, three indentations are made in dental blocks and the selection criteria will be based on the average and standard deviation of the hardness of each block. Study time will be set in a pilot study and daily during the pH cycling, the dental blocks will be exposed to a demineralizing solution (the composition of this solution in terms of Ca, Pi and F will be defined based on the preparation of the solution 50% saturated with respect to tooth enamel powder deciduous) (6.25 ml / mm ²) and the remineralising solution (1.5 mM calcium, 0.9 mM phosphate, 150 mM KCl, 0.050 ppm F in cacodylate buffer 20 mM, pH 7.4) (3.12 mL / mm ²), for periods of time to be predetermined in a pilot study. Immersion of the dental blocks and des remineralising solutions is 37 ° C. In addition, the dental blocks are the following treatments before and after immersion in the demineralizing solution: distilled deionized water (negative control); rinses containing 62.5 125, 250 and 375 mg F / mL. At the end of the experiment, the surface hardness of all the blocks will be reassessed. The hardness of the enamel longitudinally sectioned also be determined to assess the progression of caries lesions. Des and remineralizing solutions will be assessed for the concentration of F. In addition, the strongly bonded fluorine (fluorapatite, FA) is determined in the dental enamel blocks after acid extraction. This in vitro model of cycling pH dentifrice also be evaluated using commercially available and the same analyzes as described previously is also performed. The response variables are subjected to statistical analysis exploratory, from which is applied an appropriate test, whereas the experimental model. These analyzes will be a threshold of significance 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)

MAYARA DOS SANTOS NORONHA; DAYSE ANDRADE ROMÃO; JAIME APARECIDO CURY; CÍNTHIA PEREIRA MACHADO TABCHOURY. Effect of Fluoride Concentration on Reduction of Enamel Demineralization According to the Cariogenic Challenge. Brazilian Dental Journal, v. 27, n. 4, p. 393-398, 2016-08-00. (13/15251-9)

DE AMOEDO CAMPOS VELO, MARILIA MATTAR; MACHADO TABCHOURY, CINTHIA PEREIRA; ROMAO, DAYSE ANDRADE; CURY, JAIME APARECIDO. Evaluation of low fluoride toothpaste using primary enamel and a validated pH-cycling model. International Journal of Paediatric Dentistry, v. 26, n. 6, p. 439-447, NOV 2016. (12/03105-5, 13/15251-9)