Cytotoxicity of dentin conditioners and primers on human periodontal ligament cells in vitro.

Purpose: To examine the cytotoxicity of dentin conditioners and primers on human periodontal ligament (PDL) cells in vitro.

Materials And Methods: Primary PDL cells were plated in 96 well culture plates and exposed to 100 microL of test solutions. Undiluted Cavity Conditioner (CC), Vitremer Primer (VP), Uni-Etch (UE), All-Bond 2 (AB), Gluma conditioner (GC), and Gluma primer (GP) were examined at full strength and at 1/100 and 1/1000 dilutions in culture medium. Cytotoxicity of the undiluted material was determined immediately following exposure of the cells to the test substance. Cytotoxicity of the diluted materials was determined immediately following a 300-second exposure of the cells to the test solution, as well as 24 hours after removal of the test solution. Cytotoxicity was expressed as lactate dehydrogenase activity retained within the cells following exposure divided by the activity in unexposed control cells.

Results: Exposure to each undiluted test substance resulted in severe damage to the cells (78.2-100%). At 1/100 dilution, only exposure to UE resulted in significant cytotoxicity (72.9%) immediately following removal of the solution. But significant cytotoxicity (21-100%) was evident in cells 24 hours after removal of each of the materials. At 1/1000 dilution, exposure to UE (14.8%) and GP (27.2%) resulted in mild cytotoxicity. Twenty-four hours after removal of the solutions, there was a mild but significant cytotoxic effect of each of the test substances (18.5-49.4%).