A long-term ''in vitro study on resin/biomineralized dentin bonding

Author(s)

Kelly Maria Silva Moreira

• Document type: Doctoral Thesis
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2020-09-14

Examining board members

Regina Maria Puppin Rontani; Alberto Carlos Botazzo Delbem; Saul Martins de Paiva; Fernanda Miori Pascon; Carolina Steiner Oliveira

• Advisor: Regina Maria Puppin Rontani

Abstract

The aim of this thesis was to determine the bonding longevity of the resin/caries-affected dentin (CAD) after remineralizing treatment with 0.2% sodium fluoride (NaF), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP/MI Paste™) or peptide P11-4 (Curodont Repair™), after 24-hour, 6- and 18-month of storage in Simulated Body Fluid (SBF) under modified simulated pulpal pressure (MSPP). The sample consisted of 255 caries-free third molars and CAD production was done by biological method using S. mutans biofilm. The teeth were randomly distributed into 5 groups according to the treatment of dentin surfaces: G1: Sound dentin (SD); G2: CAD; G3: CAD + 0.2% NaF (CAD/NaF); G4: CAD + CPP-ACP (CAD/MP); G5: CAD + Curodont™ Repair (CAD/Cr). Sequentially, the dentin was submitted to bonding with AdperTM Single Bond 2 and a block of FiltekTM Z350 resin composite (4mm height) was built over it. The resin/dentin sets were storage in SBF/MSPP at 37ºC. After 24-hour, 6- and 18-month, the resin/dentin was checked by microtensile bond strength (?TBS) and interface sealing using nanoinfiltration; in situ zymography and micro-computed microtomography (µ-CT scanning) were carried out to gelatinolytic activity and mineralization, respectively. The failure mode was analyzed by Scanning Electron Microscopy. Data from µTBS, µ-CT scanning, and nanoinfiltration and hybrid layer formation/degradation were submitted to two-way ANOVA and Tukey tests, and from failure patterns and in situ zymography, to Kruskal-Wallis and Dunn tests ('alf'=5%). CAD/MP (p<0.001) and CAD/Cr (p<0.001) showed higher µTBS than CAD/NaF at 24-hour, 6- and 18-month. CAD/NaF showed significantly similar values than CAD, whereas CAD/MP resembled the SD. CAD/Cr also reached significantly values close to SD, at 24-hour and 18-month. In relation to failure mode, CAD and CAD/NaF presenting higher percentage of adhesive fracture and, SD, CAD/MP and CAD/Cr with most mixed fracture (p<0.001) over time. SD, CAD/MP and CAD/Cr presented significantly smaller silver nitrate infiltration and proteolytic activity in the adhesive layer, at the 24-hour and increased after 6- and 18-month (p<0.001). The mineral radiopacity in the demineralized increased to the CAD/MP and CAD/Cr groups (p<0.001). Therefore, the treatment of caries-affected dentin with CPP-ACP and Curodont Repair™ increased µTBS and mineral radiopacity, besides they decreased the nanoinfiltration and proteolytic activity. So, remineralizing agents as CPP-ACP and Curodont Repair™ show to be a promising method in dentin remineralization and longevity of adhesive restorations added to caries-affected dentin (AU)

• FAPESP's process: 15/24927-1 - Impact of remineralizing agents on the resin/caries-affected dentin bond longevity: bond strength and nanoleakage
• Grantee: Kelly Maria Silva Moreira
• Support Opportunities: Scholarships in Brazil - Doctorate