Effect of different EDTA formulae on dental pulp stem cells viability

Abstract

Abstract

Objective: To study the effects of different EDTAs on cell viability of dental pulp stem cells (DPSCs) on root dentine.

Materials and method: Fifty-nine human extracted first mandibular premolar roots were sectioned bucco-lingually. Each half of root was cut vertically into a piece of dentine sample size 3.5X3.5X1 mm, which included root canal wall on one side. A total of 118 samples were randomly divided into 7 experimental groups of 16 each for submerging in one of the solutions for 1 minute: Endo Clean, Smearclear, Ultradent, 17% EDTA, 5.25% sodium hypochlorite, 0.9% Saline solution and DMEM culture medium as the Positive control. The negative control of 6 samples were in DMEM without cells. Three dentine samples from each experimental group were selected and examined the dentine surface with SEM. The remaining dentine samples were seeded with DPSCs and cultured. After 7 days, another 3 samples from each group were examined for cell morphology with SEM. The cell viability was determined by MTT assay from the remaining 10 samples.

Results: Percentage of cell viability in the groups of 17% EDTA, Ultradent, saline solution, and positive control were significantly higher than the Endoclean, Smearclear and 5.25% sodium hypochlorite groups (p<0.05). There was no significant difference between the groups of 17% EDTA, Ultradent, 0.9% saline solution and positive control and the Endoclean, Smearclear and 5.25% sodium hypochlorite groups (p>0.05). For dentine surfaces with SEM, the Endoclean group appeared to be mostly clear and large dentinal tubules, whereas the Smearclear group exhibited large dentinal tubules and some smear plugs. The Ultradent group presented tiny opened dentinal tubules with some smear plugs, while the EDTA group had medium opened dentinal tubules and some smear plugs. Heavy smear layer covering was observed in the sodium hypochlorite and the saline groups. For the 7 days of DPSCs culturing, the Endoclean group appeared round-shaped cells and a small number of spindle cells, whereas the Smearclear group exhibited only round cells. The Ultradent group presented mostly flat cells and small number of round and spindle cells, while the EDTA group had flat and round cells. The irregular shape cells and cell fragments were found only in the Sodium hypochlorite group. For the positive control group, the majority of cells were flat, the round- and spindle-shaped cells were rarely found.

Conclusion: In the condition of this study, cell viability of 17% EDTA Ultradent, 0.9% saline solution and positive control group was significantly higher than Endoclear, SmearClear and 5.25% sodium hypochlorite groups.