Exposure to lipopolysaccharide and calcium silicate-based materials affects the behavior of dental pulp cells

Abstract

This study assessed the cell viability, cytokine production, and mineralization potential of human dental pulp cells (hDPCs) after exposure to lipopolysaccharide (LPS) and application of calcium silicate-based materials (CSBM). Characterization of the CSBM was performed by infrared spectroscopy (n = 3). Extracts of Bio-C Repair, Biodentine, Cimmo HD, and MTA Repair HP were prepared and diluted (1:1, 1:4, and 1:16). Culture of hDPCs was established and treated or not with 1 µg/mL of LPS from Escherichia coli for 7 days. MTT assay was used to assess cell viability at 24, 48, and 72 h (n = 6). Alkaline phosphatase (ALP) activity was assayed on day 7 (n = 4). Il-10 and TNF-α were quantified by ELISA at 24 h (n = 6). Data were analyzed by ANOVA and Tukey’s test (α = 0.05). Cell viability of LPS-activated hPDCs was higher than untreated control in 48 and 72 h (p < 0.05). Differences between non-treated and LPS-activated hPDCs were observed for Biodentine and Cimmo HP (p < 0.05). The CSBM influenced the cell viability (p < 0.05). ALP activity was higher in LPS-activated hDPCs (p < 0.05). No changes in the concentration of TNF-α were observed between groups (p > 0.05). The CSBM increased the Il-10 production (p < 0.05). LPS-activated hDPCs presented increased cell viability and ALP activity. The CSBM showed mild toxicity and was able to enhance the cell viability and mineralization potential of untreated and LPS-activated hDPCs. The CSBM also induced anti-inflammatory mechanisms without compromising pro-inflammatory ones.

Key Words:
Endodontics; dental cements; dental pulp; cytotoxicity tests; cytokines