REAL–TIME CELL ANALYSIS OF CYTOTOXICITY OF DENTAL BONDING AGENTS ON HUMAN DENTAL PULP CELLS

Aim: To compare the cytotoxicity of dentin bonding agents on dental pulp cells through RTCA XCELLigence® impedance method, in order to investigate whether the self-etch adhesive would be more cytotoxic than two-step etch-and-rinse adhesive due to its higher acidity. Materials and Methods: Human dental pulp cells were obtained from healthy third molars extracted during routine clinical treatment. Two self-etching(Tokuyama Bond Force“Tb”;Shofu Beauti Bond“Bb”), and two total-etching(Dentsply PrimeB3M Adper Single Bond“Ab”) dentin-bonding agents(DBA) were diluted serially with culture medium at a ratio of 1:250, 1:500, 1:1000(v:v) and filtered. Cytotoxicity was identified by plating the pulp cells into the disposable E-plate 96 of xCELLigence® system. Results: Except for the 1:1000 dilution of Ab, each dilution of Ab was lower than the cell index of the control group at the 24th, and 48th hours. Furthermore, multiple comparison tests showed statistically significant differences between the control and each dilution of Ab (P = 0.000), except 1:1000 dilution of Ab at the 24th hour (P = 0.126). On the other hand, the cell indexes of 1:1000 dilution of Bb were higher than the cell index of the control at 24th and 48th hours, and there were statistically significant differences between them (P =0,000). At the 48th hour, 1:500 (P = 0.179) and 1:250 (P = 0.003) dilutions of Bb were lower than the control. Conclusion: Among the DBAs we used in our study, total-etch Ab showed the most cytotoxic effect. Conversely, self-etch Bb containing phosphoric acid monomer, showed the least cytotoxic effect. So, it may be more appropriate for clinical practices. Clinical relevance: Despite manufacturers’ claims, not all dentin bonding agents are biocompatible. Two-step etch-and-rinse adhesive may be less biocompatible than self-etch adhesive. Keywords: Human dental pulp cell, cell culture, cytotoxicity, dental bonding agent, xCELLigence® system.