Evaluation of the effect of using experimental dentifrices with epigallocatechin 3-gallate (EGCG) and chitosan in controlling the progression of dentin erosion

• Grant number: 23/07053-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: August 31, 2024
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Silmara Aparecida Milori Corona
• Grantee: Heloisa Domingues Lodi
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The increasingly frequent occurrence of non-carious cervical lesions, such as dental erosion, triggers a population's search for treatments that can control the progression of lesions and associated symptoms. In this scenario, inhibitory mechanisms of matrix metalloproteinases, enzymes activated by the acidic environment and capable of initiating erosive wear proteolytic actions, emerge with the aim of reducing collagen loss in dentin and, consequently, dental erosion. Among the substances under study, epigallocatechin-3-gallate (EGCG) and chitosan stand out. The objective of this project is to evaluate the effects of experimental toothpaste containing EGCG and/or chitosan on the progression of dentin erosion. For the study, bovine dentin specimens (5mm in diameter) will be randomly divided into 5 treatment groups: I - Base toothpaste; II - Toothpaste containing fluoride; III - Toothpaste containing EGCG; IV - Toothpaste containing chitosan nanoparticles; V - Toothpaste containing chitosan nanoparticles encapsulated with EGCG. For the formation of dentin erosion lesions, the specimens will be immersed in 5 mL of 1% citric acid solution (pH ~2.3) for 10 minutes. After simulating erosive lesions on dentin, the specimens will be immersed four times a day (08:00, 12:00, 15:00, 18:00) in citric acid (2 minutes, 0.3%, pH 2.6), followed by immersion in 5 mL of artificial saliva for 60 minutes. The toothpaste will be applied in the form of a slurry (ratio of 3g of toothpaste to 10 mL of distilled water) and subjected to mechanical brushing (45 strokes, 2N force, totaling 2 minutes of sample exposure to the toothpaste) 30 minutes after the first and last acid challenge, i.e., twice a day (08:30, 18:30). This cycle will be repeated for 5 days. Quantitative response variables will be obtained through analyses of dentin roughness and microhardness (Knoop). The qualitative variable will be analyzed through scanning electron microscopy. The obtained results will be analyzed. If there is homogeneity of variance and normal distribution of data, a parametric test will be performed using Analysis of Variance; otherwise, a non-parametric test will be employed.