Immediate Effect of Biomimetic Agents on Caries-Affected Dentin Bond Strength

OBJECTIVE: The purpose of this study was to evaluate the effect of the P11-4 Self-Assembly Peptide and Dentin Matrix Protein 1 (DMP-1) on the microtensile bond strength (μTBS) to Caries-Affected Dentin (CAD) after 24h. METHODS: Dentin slices were sectioned from 48 human third molars, randomly divided into six groups (n = 8): sound dentin [C+]; CAD [C]; CAD with DMP-1 [DMP-1] at 1μg/ml; CAD with P11-4 [P11-4] at 1 μg/ml; CAD with P11-4 [1P11-4] at 1mg/ml; and CAD with a combination of DMP-1 at 1 μg/ml and P11-4 at 0.5 μg/ml [DMP-1/P11-4]. Artificial caries lesions were created on the dentin surfaces of CAD groups (S.mutans, UA159). After selective caries removal, the respective treatments were applied. A 50μL dose of each biomineralization agent was used on the DAC for 5 minutes, and excess removed. Subsequently, 50μL of a supersaturated calcium and phosphate solution was added for 1 minute. The bonding steps followed manufacturer's guidelines (Adper™ Singlebond2, 3M™ Oral Care), and a resin composite layer was added. Specimens were kept in Simulated Body Fluid solution (SBF) for 24 hours at 37ÅãC, simulating pulpal pressure. Sectioned beams (1mm2) were submitted to μTBS test. Group comparisons utilized one-way ANOVA, Tukey post hoc tests, and Dunnett's test against control groups, with pre-set α = 0.05. Chi-square test was conducted on the failure pattern (CI = 95%). RESULTS: C+ presented the highest μTBS values (p<0.05). 1P11-4 and the DMP-1/P11-4 exhibited significantly higher μTBS compared to C- (p<0.05). DMP-1 and P11-4 were similar to C- (p<0.05). The experimental groups showed a decrease in premature failure rates and an increase in mixed failure compared to C- (p < 0.001). CONCLUSIONS: 1P11-4 and DMP-1/ P11-4 enhanced bond strength to CAD, with 1P11-4 achieving approximately 60% of μ-TBS values of the C+. Biomimetic analogues improved immediate bond strength between adhesive/composite and CAD. IMPLICATIONS: Minimally Invasive Dentistry advocates for selective caries removal, involving the removal of infected dentin, which is necrotic and unable to remineralize, while preserving the affected dentin at the bottom, which has the potential for remineralization. However, adhesion to affected dentin is often poor. In this study, biomimetic agents were used as a surface treatment to remineralize caries-affected dentin, aiming to improve immediate bond strength.