Cytotoxicity of Recent Dentine Bonding Agents on Mouse Fibroblast Cells

Objectives: This study compared the cytotoxicity of the polymerized bonding agents ScotchBond 1, Prime & Bond NT and Xeno III through artificial membranes as well as thin dentin discs (after its reaction with apatite), Clearfil Protect Bond (CPB) as such, as well as the primer part of CPB and the bond part of CPB separately, on 3T3 mouse fibroblast cells. Methods: Near confluent 3T3 cells were exposed to medium (DMEM) extractions from the various polymerized agents mentioned above and the cell viability (survival rate) was measured using the standard MTT assay and related to the non-exposed controls. Results: All bonding agents as such were found to be cytotoxic towards the 3T3 cells with Xeno III (25% survival rate) and CPB (35%) the most cytotoxic. Of the two parts from CPB the bond part was the least toxic (91% survival rate), but the primer part (containing the anti-bacterial pyridinium molecule) was very toxic (30% survival rate). ScotchBond 1 (59% survival rate) and Prime & Bond NT (62% survival rate) were not statistically different (Kruskal-Wallis Test, p>0.05). However, the survival rate of Xeno III (25% through membrane as well as dentin discs) and Clearfil Protect Bond (35%) were significantly lower than that of the other two bonding agents, with Xeno III significantly the most toxic (p<0.05). Conclusion: It is concluded that all 4 dentin bonding agents are cytotoxic of which Xeno III the most toxic even after its reaction with apatite (through dentin discs). The most toxic part of CPB was found to be the primer part containing the pyridinium linked molecule.