Electron Beam Irradiation of Resin Luting Agents - a Cytotoxic Evaluation on Dental Pulp Cells

Aim: The aim of this study was to evaluate the cytotoxicity of three resin luting agents Rely X luting cement, Rely X luting 2 cement and Clearfil SA luting cement before and after electron beam irradiation.
Materials and Methods: Growth and maintenance of cell cultures of human pulp cells was done in Dulbecco’s modified Eagle’s Medium (DMEM). The test samples were divided into two Categories: Irradiated Category and Non-radiated Category. Samples in Irradiated category were exposed to electron beam radiation at 200Gy. Three subgroups of radiated category and non radiated category were made. All the samples were subjected to MTT assay and spectrophotometric analysis and their cytotoxicity was assessed. Statistical analysis was done using t test.
Results: Evaluation of Rely X luting Cement showed that radiated samples of powder, liquid and set cements showed decreased cell viability than non radiated samples. In Case of Rely X luting 2 cement, radiated samples showed increased cell viability for Paste A and Paste B samples. But in set material, irradiated samples showed decreased cell viability as compared to non radiated samples. For Clearfil SA luting Cement, Paste B showed increased cell viability for radiated samples. Paste A and Set cement of radiated samples showed decreased cell viability than non radiated samples.
Conclusion: In the present study , the increased cytotoxicity of irradiated samples may be due to increase in the release of unbound monomers which may be due to chain breakage after irradiation and a reduction in the cytotoxicity which may be due to the cross linking of unbound monomers during irradiation.