Bond strength to intraradicular dentin of anatomical posts obtained by additive and subtractive manufacturing after hydrothermal aging

• Grant number: 24/03227-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: José Maurício dos Santos Nunes Reis
• Grantee: Giovanna França Silva
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

This study aims to evaluate the bond strength to dentin of systems used to create intraradicular anatomical posts. Forty endodontically treated mandibular canines will be used. After removing 2/3 of the root canal, the sample will be randomly divided into 4 experimental groups (n=10) and a post/core will be made according to the systems: PFVA (resin core associated with an anatomized fiber post with Grandioso nanohybrid composite - Voco); PABV (post/core printed with Smart Print Bio Vitality resin - SmartDent); PAVS (post/core printed with Varseo Smile Crown Plus Bego - Wilcos); PAFC (post/core milled from FiberCAD block - Angelus). The posts/cores will be cemented by means of Futurabond self-etching and dual polymerized adhesive system and Rebilda DC (Voco) cementing agent. Afterwards, the sample will be subjected to thermocycling (10,000 cycles; 5-55 °C; 30 s baths). The roots will then be included in PVC cylinders (15 x 16 mm) with polystyrene resin and subjected to section in the cervical, middle and apical thirds (1.0; 4.0; and 7.0 mm from the cervical to the apical surface). Twenty specimens will be subjected to analysis by laser confocal microscopy in order to carry out qualitative assessments regarding the thickness and porosity of the resin cement layer. The specimens will proceed to the mechanical push-out test (EMIC DL2000; load cell 2.0 kN; 0.5 mm/min). The results will be obtained in Newton and converted into MPa. The interfaces will be analyzed under a stereomicroscope (20X) to determine the failure patterns: adhesive, mixed or cohesive. Representative images of the fracture patterns will be obtained by SEM. Data will be tabulated and subjected to normality and homoscedasticity analysis for the application of statistical methods (±=0.05).