Effect of polyvinylphosphonic acid on resin-dentin bonds and the cytotoxicity of mouse dental papilla cell-23

Statement of problem. Polyvinylphosphonic acid (PVPA) could be used as a biomimetic remineralization analog and a matrix metalloproteinases (MMPs) inhibitor. However, studies are lacking regarding the performance of PVPA in dental bonding systems for maintaining the durability of the resin-dentin bond. Purpose. The purpose of this in vitro study was to investigate the effect of PVPA on the durability of resin-dentin bonds and the viability of mouse dental papilla cell-23 (MDPC-23). The mechanical properties of resin-dentin interfaces during long-term storage were analyzed, and the potential application of PVPA as a biomimetic remineralization analog in adhesive dentistry was evaluated. Material and methods. Seventy-five extracted noncarious human third molars were collected and randomly divided into 5 groups, and then the microtensile bond strength (mu TBS) data and scanning electron microscope (SEM) images were used to evaluate the preservation condition of resin-dentin bonds after 1 day, 6 months, and 1 year of storage. The cytotoxicity of PVPA was detected by cell proliferation assay and cell apoptosis assay. Results. Compared with the control and chlorhexidine (CHX) groups, the combined group (treated with both 200-mu g/mL PVPA and biomimetic remineralization) had excellent bond durability. The exposed collagen fibril from the PVPA-treated groups (included 200-mu g/mL and 500-mu g/mL PVPA groups and a combined group) still showed integrity after 1 year of storage when compared with the control group. PVPA up to 500 mu g/mL showed no cytotoxicity to MDPC-23 and did not inhibit cell growth. Conclusion. This study offered evidence that PVPA did not result in cytotoxicity at low concentrations as an MMP inhibitor and a biomimetic remineralization analog. In addition, the application of PVPA improved bond strength and preserved collagen integrity after 1 year of in vitro storage.