Evaluation of effect of a new cystatin derived from sugarcane on the viability of microcosm biofilm and on enamel demineralization prevention

• Grant number: 18/02345-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2018
• End date: December 31, 2020
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: Gabriel Domingues Camiloti
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

In dentistry, various diseases such as caries and tooth erosion have been studied. Recently, a new cystatin derived from sugarcane (Cane CPI-5) was produced in a heterologous expression system and was shown to strongly bind to enamel, protecting against tooth erosion in vitro. However, the protective effect of Cane CPI-5 against dental caries, caused by acids produced by bacteria organized in a biofilm, after sugar consumption, has never been evaluated. The objective of this study is to evaluate the effect of different concentrations of Cane CPI-) on the viability of a microcosm biofilm as well as on the prevention of enamel demineralization. For the formation of a microcosm biofilm, saliva will be collected from 10 healthy subjects, who have not brushed their teeth in the last 24 hours and have not ingested food or drinking liquids in the last 2 hours. Saliva will be diluted (70% saliva and 30% glycerol) and further mixed to McBain saliva (1:50) for the formation of a cariogenic biofilm. Bovine enamel samples (4 mm x 4 mm) (n=60), will be prepared for the formation of a microcosm biofilm for 5 days, which will be treated daily (1x60s/day), with two concentrations of Cane CPI-5 (0.1 or 1.0 mg/ml), solution of NaF (250 ppm), 0.12% chlorhexidine (positive control) or PBS (negative control). In Step 1, live and dead bacteria in the biofilm will be evidenced by fluorescence using confocal microscope. In Step 2, the demineralization caused by the biofilm in the studied conditions will be measured by transverse microradiography. The data will be subjected to appropriate statistical analysis (parametric or non-parametric test, p <0.05). (AU)