Cytotoxicity of Self-Etch Versus Etch-and-Rinse Dentin Adhesives After 48 h: An In Vitro Study

Objectives: Six dentin adhesives were tested in vitro regarding their cytotoxicity toward human fibroblasts. AdheSE, Clearfil SE Bond, Hybrid Bond, One-up Bond F Plus, Optibond Solo Plus, and Syntac were tested using a cell culture model. The several components of dentin adhesives, like the primer and bonding, were analyzed as single and additive applied components as specified by the manufacturer for application in vivo. Methods: Seventy-five Petri dishes were produced per adhesive and control group, and all 525 Petri dishes were evaluated using multiparametric strategies, i.e., using multiple methods to strengthen the reliability of the results. The multiparametric strategies consisted of automated cell counting for viability, microscopic morphological assessment and lastly of reactivity grading according to ISO 10993-5. These assessments were performed after our initial investigation, and the observation period was extended from 24 h to 48 h. Results: AdheSE, Clearfil SE Bond, One-up Bond F Plus, and Optibond Solo Plus showed statistically significant reductions in viable cells relative to the cell control. All dentin adhesives except Clearfil SE Bond showed a statistically significant difference regarding the reactivity index in the application comparison. Conclusions: The test materials showed a moderate degree of cytotoxicity, with no statistically significant difference between the tested self-etch and etch-and-rinse dentin adhesives. However, the results show statistically significant differences between the adhesives when applied sequentially and once. Further research addressing mechanisms of cytotoxicity is needed for advancement in this field.