Transdentinal effect of surface pre-reacted glass ionomer (S-PRG) fillers on odontoblast-like cells

• Grant number: 21/06480-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2021
• End date: April 30, 2023
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Josimeri Hebling Costa
• Grantee: Caroline Meronha de Lima
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The bioactive effects of restorative materials incorporated with surface pre-reacted glass-ionomer (S-PRG) fillers are attributed to the eluted ions. For this reason, the eluate obtained from S-PRG fillers has been investigated for several therapeutic applications aimed at increasing the longevity of restorations and reducing the progression of caries and erosion lesions. However, the effect of these ion-releasing particles, when applied on dentin, on pulp cells is still unknown. Therefore, the objective of this study will be to evaluate the transdentinal response of odontoblast-like cells after the application of S-PRG eluate. Thirty-two healthy third molars will be selected and transversally cut to obtain coronal dentin discs (0.4 mm thick). The hydraulic conductance of the discs will be assessed to allow obtaining specimens with similar permeability. After adapting the discs in artificial pulp chambers, MDPC-23 odontoblast-like cells will be seeded on the pulpal surface of the discs. The occlusal surface will be treated with (n=8/group): 29% hydrogen peroxide (positive control), S-PRG eluate followed by water rinsing, or S- PRG eluate without rinsing. As a negative control, discs will receive ion-free water. After 48 h, the cells cultured on the discs will be evaluated for viability (alamarBlue; n=8) and morphology (SEM; n=2). The conditioned medium (extract) will be collected and applied on new plate-seeded MDPC-23 (n=8). After 24 h of contact with the conditioned media, the plate-seeded cells will be evaluated for viability (alamarBlue) and the formation of mineralized nodules (Alizarin Red). Each dataset will be analyzed for the normal distribution (Shapiro-Wilk) and homogeneity of variances (Levene) for the application of appropriate statistical tests at a significance level of 5%. The analysis of cell morphology in SEM will be descriptive. (AU)