Effects of Intracanal Antimicrobials on Viability and Differentiation of Stem Cells From the Apical Papilla: An In Vitro Study

Gavin Raddall; Isabel Mello; Brendan M Leung

doi:10.1016/j.joen.2022.04.003

Effects of Intracanal Antimicrobials on Viability and Differentiation of Stem Cells From the Apical Papilla: An In Vitro Study

J Endod. 2022 Jul;48(7):880-886. doi: 10.1016/j.joen.2022.04.003. Epub 2022 Apr 9.

Authors

Gavin Raddall¹, Isabel Mello², Brendan M Leung³

Affiliations

¹ Department of Dental Clinical Sciences, Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia, Canada.
² Department of Dental Clinical Sciences, Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia, Canada. Electronic address: isabel.mello@dal.ca.
³ Department of Applied Oral Sciences, Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia, Canada; School of Biomedical Engineering, Faculties of Medicine and Engineering, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Pathology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.

PMID: 35405159
DOI: 10.1016/j.joen.2022.04.003

Abstract

Background: Recent studies have indicated that intracanal antimicrobials used to disinfect the root canal in regenerative endodontic therapies (RETs) may be cytotoxic to stem cells from the apical papilla (SCAP), leading to inconsistent treatment outcomes. However, the effects of intracanal antimicrobial agents on the odontogenic differentiation capacity of SCAP at sub-lethal concentrations have not been investigated. The aim of this study was to determine the effects of intracanal antimicrobials on SCAP viability and odontogenic differentiation capacity using a clinically relevant concentration range (0.1-0.8 mg/mL).

Methods: Immature human third molars were collected from 71 patients and the apical papillae were harvested to form single-cell suspensions. The cytotoxic effects of intracanal antimicrobials including double antibiotic paste (DAP), triple or modified-triple antibiotic paste (TAP or MTAP), and calcium hydroxide (Ca(OH)₂) on STRO-1⁺ SCAP were assessed using AlamarBlue and Live/Dead assays after exposing cells to treatment groups for 7 days at 0.1 to 0.8 mg/mL. The odontogenic differentiation potential of STRO-1⁺ SCAP was evaluated by immunocytochemistry staining of dentin matrix protein-1 and dentin sialophosphoprotein expression.

Results: All concentrations of TAP significantly reduced STRO-1⁺ SCAP viability and odontogenic differentiation (P < .001), whereas no DAP concentrations were significantly cytotoxic. Ca(OH)₂ and MTAP concentrations below 0.4 mg/mL and 0.2 mg/mL, respectively, did not significantly reduce viability. The DAP, MTAP, and Ca(OH)₂ did not significantly impact the odontogenic differentiation capacity of STRO-1⁺ SCAP.

Conclusion: The varying effects of intracanal antimicrobials on STRO-1⁺ SCAP in vitro suggest amendments to the current root canal disinfection protocol may improve the success of RETs.

Keywords: Intracanal medicaments; odontogenic; regenerative endodontic therapies; stem cells from the apical papilla.

MeSH terms

Anti-Bacterial Agents / pharmacology
Cell Differentiation
Cells, Cultured
Dental Papilla*
Humans
Stem Cells*

Substances

Anti-Bacterial Agents