Effects of universal adhesives on dentin matrix proteins, matrix metalloproteinases and cytokine release of human pulp cells

The potential toxicity of universal adhesives, which contain various monomers, solvents and fillers is a significant research topic. This study aims to investigate the toxicity and effects of universal adhesives on dentin matrix proteins (DMP-1), matrix metalloproteinases (MMP-2, MMP-8), tissue inhibitors of metalloproteinase-1 (TIMP-1), and cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin-1 (IL-1)] in pulp cell lines. Six universal adhesives [Gluma Bond Universal (GBU), Prime&Bond Universal (PBU), Clearfil S3 Universal Bond (CS3UB), OptiBond Universal (OBU), G-2 Bond Universal (G2BU) and Bond Force II (BFII)] were assessed using MTT and ELISA cytotoxicity tests. The data obtained from MTT and ELISA tests were analyzed using two-way analysis of variance (ANOVA). The 1:1 extracts of BFII and GBU showed higher cell viability at 24 and 48 h compared to PBU, CS3B, OBU, and G2B adhesives (p < 0.001), and furthermore, the 1:1 extracts of GBU showed statistically the highest cell viability at 72 h (p < 0.001). The universal adhesives tested showed a significant decrease in TIMP-1 in pulp cells (p < 0.05), while TNF-α, IL-1, DMP-1, MMP-2 and MMP-8 levels did not change significantly. The tested adhesives exhibited varying degrees of cytotoxic effects depending on time and dose. The results indicate that the composition of these adhesives plays a crucial role in their cytotoxicity and impact on pulp cell viability. The amount and duration of adhesive application should be carefully regulated to maintain biocompatibility and ensure safe usage.