Effects of bioceramic sealer removal protocols from the dentin surface on the interface with the universal adhesive

• Grant number: 25/10056-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Milton Carlos Kuga
• Grantee: Jean Pierre Munhoz Junior
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The study aims to evaluate the effectiveness of a multifunctional experimental amphoteric surfactant solution (ExSo), compared to distilled water (ADCo), 95% ethanol (95Et), and amyl acetate (AcAm), for the removal of bioceramic cement residues (BR; BioRoot RCS) from coronal dentin (studies 1CL and 1AC) and from the root space prepared for fiber posts (studies 2CL and 2AC), as well as its effects on the adhesion interface with the universal adhesive (SU; Scotchbond Universal), used in either the etch-and-rinse (CL) or self-etch (AC) strategies.In studies 1CL and 1AC, two hundred bovine incisor crowns will be prepared, with dentin impregnated with bioceramic cement and subjected to the cleaning protocols (n=50 per protocol). Forty crowns (n=10 per protocol) will be analyzed by scanning electron microscopy to evaluate the presence of residues (500x) and count open dentinal tubules (2,000x).Eighty crowns will be used to assess bond strength using the microtensile test in a universal testing machine. Forty crowns (n=10 per protocol) will be restored with SU using the CL strategy, and the remaining crowns (n=10 per protocol) will be restored with SU using the AC strategy after 6 months. After this analysis, the specimens will be evaluated under stereomicroscopy (20x) to assess the incidence of adhesive failure patterns.For the other eighty crowns, similar protocols and strategies will be used. However, after incorporating Rhodamine B into the universal adhesive and restoring with composite resin, the crowns will be sectioned in a buccolingual direction. In the distal hemisection, the dentin penetrability of the adhesives will be measured using confocal laser microscopy (10x). In the mesial hemisection, the hybrid layer thickness will be measured by scanning electron microscopy (500x).In studies 2CL and 2AC, one hundred and twenty conical bovine incisor roots will undergo endodontic treatment and be filled with BR. Immediately afterwards, the post space will be prepared, and the root surface of forty roots will be cleaned using one of the cleaning protocols. The roots will then be longitudinally sectioned, and the dentin surface will be evaluated to check for residual debris (500x) and the incidence of open dentinal tubules (2,000x).In eighty roots, glass fiber posts will be cemented with conventional resin cement (RU; Relyx Ultimate) associated with SU, using the CL (study 2CL, n=40) or AC (study 2AC, n=40) strategy, immediately after applying the cleaning protocols. At this point, Rhodamine B will be incorporated into the adhesive. After 6 months, the specimens will be cross-sectioned in the cervical, middle, and apical thirds of the post space and subjected to push-out tests in a universal testing machine. Subsequently, the specimens will be evaluated for adhesive failure patterns, dentin penetrability of the adhesives, and hybrid layer thickness, using stereomicroscopy, confocal microscopy (10x), and scanning electron microscopy (500x), respectively.The results will be evaluated using normality and homoscedasticity tests, with a significance level of 5%. After verifying the data, appropriate statistical tests will be selected.