Surface characterization of sound and post radiotherapy irradiated dentin treated with bioactive dentifrices: an in vitro study

• Grant number: 23/14131-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: December 31, 2024
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Linda Wang
• Grantee: Julia Alcantara Martins
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

Among the various challenges affecting dental elements, those affecting dentin are the most critical. When subjected to radiotherapy, disorganized dentin is observed, with cracks and destroyed or collapsed dentinal tubules, forming a substrate that is more susceptible to radiation caries. To reduce the effects of this condition, different approaches are being used to reinforce the substrate, in which toothpastes are the main vehicles. Among them, bioactive materials have stood out because their composition contains materials with active ingredients or those that induce dental biomineralization. Therefore, it is important to understand how these products interact with dentin tissue. The aim of this in vitro, parallel and blind study is to comparatively analyze products based on different bioactive technologies in the treatment of irradiated dentin after radiotherapy. The analysis will involve two factors: material in 5 levels (control - Colgate total 12, Clinpro 5000, Elmex Opti-namel, Biomin F and S-PRG 5%) and condition, subdivided into 2 levels (control - sound dentin- S - stored in artificial saliva) and irradiated (I- total dose 70Gy - 3x 20Gy and 1x 10Gy with an interval of 2 days). The main response variables to be investigated are wettability, surface roughness and qualitative surface analysis by scanning electron microscopy. Fifty caries-free human third molars will be used, which will be stored in 0.1% thymol solution, pH 7.0. The crowns will be sectioned using a diamond disc under cooling with deionized water. To measure the wettability each dentin surface will be tested by calculating the contact angle. For the evaluation of surface roughness, a Hommel Tester T1000 profilometer will be used to determine the difference between the average of 5 initial readings and 5 final readings per specimen. Microscopy images will be qualitatively assessed. Statistical analyses will be processed and the Analysis of Variance tests and analysis of multiple comparisons will be applied by 2-way ANOVA and Tukey tests (p<0.05).