CARACTERIZATION OF DENTIN SURFACE AND BIOLOGICAL PROPERTIES OF ERODED DENTIN TREATED WITH BIOACTIVE AGENTS.

• Grant number: 24/21213-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: December 31, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Linda Wang
• Grantee: Sara de Andrade Pereira
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Associated research grant: 23/05793-0 - Impact of bioactive technologies on altered dentin by erosive tooth wear or post irradiated with radiotherapy: biological assessment by in situ zymography and related physical-mechanical properties, AP.R

Abstract

Erosive tooth wear, characterized by dentin exposure, has emerged as a significant clinical issue, often leading to dentin hypersensitivity, and impacting patients' quality of life. Dentin exposure is a primary feature of the early stages of this wear, necessitating effective treatments. Bioactive technologies, which control demineralization and promote remineralization, are being integrated into toothpastes due to their efficacy in home use, allowing patients to actively participate in the recovery process. This in vitro study aims to evaluate the interaction of different bioactive toothpastes with the surface of eroded dentin, seeking to understand their impact on remineralization and the protection of dental structure. The analysis will involve two factors: 1- material at five levels: No treatment (control 1), Colgate Total 12 (control 2), Elmex Erosion Protection, Biomin F, and 5% S-PRG paste; and 2- dentin condition at two levels: sound (control) and eroded (0.1% citric acid - 4 daily immersions/90 seconds/5 days). Variables response will include molecular profile characterization of the substrate using Fourier Transform Infrared Spectroscopy (FTIR), surface microhardness, wettability, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). Ninety third molars will be cleaned and sectioned to expose the superficial dentin in 5 mm discs. After cleaning, the dentin will be polished with 600 and 1200 grit sandpapers for 30 seconds each, and the specimens will be immersed in an ultrasonic bath to remove debris. The toothpastes will be applied as a slurry diluted in deionized water (1:3), with application twice daily for 7 days. For molecular profile analysis, 45 specimens will undergo FTIR, identifying bands for type I collagen (1645 cm¿¹, 1550 cm¿¹, 1240 cm¿¹) and mineral components (888-816 cm¿¹ and 1170-780 cm¿¹). Same specimens will be used for the surface microhardness and wettability assessments. For SEM, 45 specimens will be treated, metalized, and analyzed at 1500x magnification to study the surface. CLSM will be used to obtain reflectance and fluorescence images, analyzing the dentin surface pattern up to a depth of 20 ¿m. Data will be statistically analyzed, considering their homogeneity and distribution, using appropriate tests to be determined.