Protective role of acquired enamel pellicle formed for different times and of Statherin peptide against initial dental erosion: evaluation using a new hand-held optical reflectometer

• Grant number: 19/16815-0
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): January 01, 2020
• Effective date (End): June 30, 2020
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal researcher: Marília Afonso Rabelo Buzalaf
• Grantee: Talita Mendes Oliveira Ventura
• Supervisor abroad: Adrian Lussi
• Home Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Research place: University of Bern, Switzerland
• Associated to the scholarship: 17/05031-2 - Proteomic analysis of the acquired enamel pellicle and saliva in patients with head and neck cancer that are submitted radiotherapy, BP.DR

Abstract

Dental erosion is a chronic lesion, characterized by the loss of hard tissue due to exposure to acids of non-bacterial origin. The acquired pellicle (AP) is an integument formed in vivo as a result of the selective adsorption of salivary proteins on the surface of the tooth, which also contains glycoproteins and lipids. The presence of proteins in AP forms a protective interface on the surface of the tooth, participating in all the interfacial events that occur in the oral cavity. It is an organic film, bacteria-free, that covers the dental tissues. Works have focused on the characterization and protective impact of the AP formed on the enamel surface. Studies involving the incorporation of proteins into the acquired pellicle have been proposed as a new strategy for the control of dental erosion. However, probably the greatest challenges in dental erosion research is to find an assessment method that is able to quantify dental erosion clinically. Recently, a new hand-held device called Reflectometer Optipen has been developed by Prof. Lussi´s group and showed good results to assess initial erosion in vitro. Due to its characteristics, this device has a great potential to be employed clinically. To date, the device is not commercially available and is only found at Prof. Lussi´s laboratory. Thus, it is quite important that researchers from other groups get training on the use of this device for future clinical application. Based on this, the objective of this study is to evaluate the protective effect of the acquired enamel pellicle (AEP) in different times of formation and of Statherin peptide added to saliva, to protect against initial dental erosion in vitro, as evaluated using the Reflectometer Optipen. One hundred forty specimens of human enamel (molars) will be prepared after prophylaxis, initial surface reflection intensity (SRI) will be measured using the Reflectometer Optipen. The samples will be divided into seven groups (n=20) according with the treatment: 1) 3 min of formation of AEP, 2) 15 min of formation of AEP; 3) 30 min of formation of AEP; 4) 60 min of formation of AEP; 5) 120 min of formation of AEP; 6) 240 min of formation of AEP; 7) 120 min of formation of AEP in saliva containing 1,88 X 10-5 M Statherin peptide (DpSpSEEKFLRRIGRFG). They will be incubated in stimulated pooled saliva for the different times of formation, containing or not Statherin peptide, at 37°C under stirring. For the erosive process, the samples will be incubated in 1% citric acid (pH 3,6) for 1 min at 37°C. Each specimen will be treated once/day over 3 days. After the last erosive challenge, specimens will receive prophylaxis and final SRI will be measured and relative SRI loss will be calculated. Data will be analyzed by appropriate statistical tests, after normality and homogeneity evaluation (p<0.05).