Effect of Electron Beam Irradiation on Resin– Based Root Canal Sealer –AH Plus: A Cytotoxic Evaluation

Aims: To evaluate and compare the cytotoxicity of a resin-based root canal sealer, AH Plus, before and after electron beam irradiation and to assess the effect of three different doses of electron beam radiation (1 KGy, 3 KGy and 5 KGy) on cytotoxicity of the sealer.
Place and Duration of Study: Department of Conservative Dentistry and Endodontics, A.B. Shetty Memorial Institute of Dental Sciences, Nitte University, Deralakatte, Mangalore, India and Microtron Centre; Department of Physics Mangalore University; Mangalore, India between July 2012 and November 2012.
Methodology: Gingival fibroblasts were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) and sub confluent monolayers of cells were obtained. The study included two categories- Irradiated and Non-irradiated. Both of them were further divided into four groups of paste A, paste B, Mixed and Set sealer of AH plus. Samples in irradiated category were further divided into 3 subgroups based on electron beam irradiation dose-1, 3 and 5 KGy. Sample elutes were prepared using standard extraction procedure. The elutes of all sealers from both the categories were added to the human gingival fibroblast cultures and their cytotoxicity was assessed by MTT assay. The results were tabulated and subjected to statistical analysis using One–way ANOVA (Analysis of variance) test and Tukey’s HSD Test.
Results: Cell viability was minimum in Paste M irradiated with 5 KGy irradiation dose and maximum in non-irradiated SET AH Plus sealer. The results of the present study showed positive effect of irradiation in the epoxide paste of AH Plus sealer. The positive effect here is mainly based on experimental data of percentage cell viability and not on statistical significance. Multiple comparisons of different doses of electron beam irradiation on percentage of cell viability in all the samples showed a highly statistically significant difference at 3 KGy of electron beam radiation (P value = 0.008).
Conclusion: Further research should to be performed with higher doses of electron beam radiation on epoxide paste in order to notice further improvement in physical as well as biological properties in order to generate an upgraded version of the present dental materials.