Effect of Different Intracanal Medicaments on the Viability and Survival of Dental Pulp Stem Cells

Abstract

Background: Stem cells play an important role in the success of regenerative endodontic procedures. They are affected by the presence of medicaments that are used before the induction of bleeding or the creation of a scaffold for endodontic regeneration. This study examines the effects of different intracanal medicaments on the viability and survival of dental pulp stem cells at different doses and over different exposure times.

Methods: Dental pulp stem cells were cultured from healthy third molar teeth using the long-term explant culture method and characterized using flow cytometry and exposed to different concentrations of calcium hydroxide, doxycycline, potassium iodide, triamcinolone, and glutaraldehyde, each ranging from 0 (control) to 1000 µg/mL. Exposure times were 6, 24, and 48 h. Cell viability was measured using the MTT assay, and apoptosis was measured using the Annexin V-binding assay.

Results: All medicaments significantly reduced cell viability at different concentrations over different exposure times. Calcium hydroxide and triamcinolone favored cell viability at higher concentrations during all exposure times compared to other medicaments. The apoptosis assay showed a significant increase in cell death on exposure to doxycycline, potassium iodide, and glutaraldehyde.

Conclusion: The intracanal medicaments examined in our study affected the viability of dental pulp stem cells in a time and dose-dependent manner. They also adversely affected the survival of dental pulp stem cells. Further studies are needed to better understand the effect of prolonged exposure to medicaments according to clinical protocols and their effect on the stemness of dental pulp stem cells.

Keywords: calcium hydroxide; dental pulp; doxycycline; endodontic regeneration; root canal medicaments; stem cells.

Figure 1

Characterization of DPSCs for mesenchymal stem cell properties. (A) Photomicrograph of DPSCs at passage 4. Scale bar = 100 μm. (B–H) DPSCs were checked for MSC-specific positive markers CD73, CD90, and CD105 and MSC-specific negative markers CD34, CD45, and HLA-DR.

Figure 2

MTT assay for the assessment of cytotoxicity. (A–O) DPSCs were treated with various concentrations of individual drugs (0 µg/mL, 10 µg/mL, 25 µg/mL, 50 µg/mL, 100 µg/mL, 250 µg/mL, 50 µg/mL, and 1000 µg/mL) for 6, 24, and 72 h, and a comparative analysis was done to check the cytotoxicity of the drugs to DPSCs. ns is not significant; * p < 0.05 and ** p < 0.01.

Figure 3

Morphologic and apoptosis analysis in DPSCs treated with selected concentrations of drugs. (A–F) Morphology of DPSCs after treatment with selected concentrations of drugs. (G–N) Comparative analysis of apoptosis by annexin V assay. ns is not significant; * p < 0.05.