Prospecting the effects of biomodulators containing epigallocatechin 3-gallate on the adhesion interface between adhesive systems and endodontically modified dentin

• Grant number: 25/14785-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Milton Carlos Kuga
• Grantee: Gabrielle Sampaio da Fonseca
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The study aims to evaluate the effects of conditioning endodontically modified dentin, both of the dental crown and the root canal, with epigallocatechin 3-gallate (EGCG) in liquid (H, water) or gel (A, Aristoflex) formulations, on the adhesion interface with the adhesive systems used in the etch-and-rinse strategy (AS, Adper Scotchbond Multipurpose or (SU, Scotchbond Universal Plus). In study 1, after the dentin of 76 dental crowns were subjected to 2.5% sodium hypochlorite solution, acid conditioning was performed, biomodulated with EGCG-H or EGCH-A, AS or SU were applied, and restored with composite resin, they will be distributed into 6 groups, according to the adopted protocol. Sixteen crowns (n = 4 per group, n = 5 specimens per dental crown) will be used for the microshear bond test, in a universal testing machine and in sixty crowns (n = 10) the adhesive interface will be evaluated by measuring the tags extension, using laser confocal microscopy (10x). In study 2, 60 roots of bovine conoid incisors will be endodontically treated, and the post space will be immediately prepared. A 2.5% sodium hypochlorite solution will be used during the chemical-mechanical preparation and also in the post space. The roots will then be distributed into 6 groups, and the dentin of the post space will be subjected to the same protocols described above. Immediately afterward, a fiber post will be cemented in 30 roots (n = 10, from each protocol) with Relyx ARC (RA) resin cement in the groups, using AS, and in 30 roots (n = 10, from each protocol) with Relyx Universal (RU) resin cement, using SU. The roots will then be transversely sectioned into the cervical, middle, and apical thirds, and the specimens will be subjected to push-out testing in a universal testing machine. The adhesive failure pattern will be analyzed by stereomicroscopy, and the tags extension will be measured using confocal laser microscopy. The specimens to be analyzed by microshear bond testing and the tooth roots will be evaluated after 6 months of immersion in distilled water, and the remaining specimens will be evaluated after 24 hours. The data obtained will be initially evaluated by the Shapiro-Wilk test, and if the data show homoscedasticity, they will be further analyzed by ANOVA (P = 0.05). (AU)