The direct cytotoxic effects of medicaments used in endodontic regeneration on human dental pulp cells.

AIM: The purpose of this in vitro study was to evaluate the effects of intracanal medicaments commonly used in endodontic regeneration on the survival of human dental pulp cells (DPCs).
METHODS: DPCs were cultured and exposed to either no medicament treatment or low concentrations (0.3-5 mg ml(-1) ) of calcium hydroxide [Ca(OH)2 ], triple antibiotic paste (TAP), or double antibiotic paste (DAP) for 3 days. After that, toxicity to the DPCs was determined by lactate dehydrogenase activity assays (LDH) and cell proliferation was measured by colorimetric assays (WST-1). Two-way anova followed by Fisher's protected least significant differences was used for statistical analyses (α = 0.05).
RESULTS: The group-by-concentration interactions were significant for the LDH and WST-1 assays (P < 0.0001). For the LDH assays, only the highest tested concentration (5 mg ml(-1) ) of Ca(OH)2 and TAP caused significant toxicity to the DPCs compared with the untreated control, while four tested concentrations of DAP (0.5, 1, 2.5, and 5 mg ml(-1) ) caused significant toxicity to the DPCs compared with the untreated control. For the WST-1 assays, the highest concentrations that did not negatively affect the proliferation rate of DAP, TAP and Ca(OH)2 were 0.3, 2, and 2.5 mg ml(-1) , respectively.
CONCLUSION: The low concentrations of intracanal medicaments tested in this study were not cytotoxic in cultured cells. However, these concentrations are much lower than the concentrations that have been advocated in endodontic regeneration. Furthermore, the negative effects of TAP on DPCs were detected at lower concentrations by using the WST-1 assays than by measuring the LDH release.