Polyvinylpyrrolidone as a primer for resin-dentin bonding

Objective: This study aimed to investigate the effects of polyvinylpyrrolidone (PVP)-containing primer (PCP) on dentin bonding.Methods: PVP and anhydrous ethanol were used to prepare the PCPs, which were prepared at concentrations of 0.5%, 1%, and 2% (w/v). These PCPs were subsequently applied to the dentin surface, denoted as E1, E2, and E3, respectively. In the control group, no primer was applied. Following the treatment, the dentin surfaces were subjected to analysis using Fourier-transform infrared spectroscopy (FTIR), and the micro-tensile bond strength (MTBS) was evaluated. The failure mode, nanoleakage, and bonding longitudinal section were observed utilizing scanning electron microscopy (SEM). Additionally, the effect of PCPs on matrix metalloproteinases (MMPs) activity was analyzed through an in situ zymography test. Data were subjected to statistical analysis using ANOVA tests (alpha = 0.05).Results: Significant alterations in the infrared resonances associated with collagen cross-linking within the collagen matrix were observed across all PCP groups. The application of PCP demonstrated a noteworthy enhancement in micro-tensile bond strength (MTBS) compared to group C (p < 0.05). Notably, group C exhibited the lowest MTBS (41 +/- 7.7 MPa), whereas group E2 demonstrated the highest MTBS (66 +/- 11.9 MPa). Even after undergoing aging, the MTBS of the PCP groups remained superior to that of group C (p < 0.05). The resin tag length in the PCP groups was found to be greater than that of group C, and the occurrence of nanoleakage was comparatively lower in the PCP groups, both before and after aging. Additionally, PCP exhibited a dosedependent inhibition of matrix metalloproteinases (MMPs) activity, which was statistically significant (p < 0.05).Conclusions: The utilization of PCP Primer exhibits notable enhancements in bond strength, mitigates nanoleakage, and suppresses enzyme activity within the hybrid layer.