Cytocompatibility and antibacterial properties of capping materials

Abstract

The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), and Biodentine (Septodont). To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at different times by both MTT and apoptosis assays. Results significantly differed among the different materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were significantly different among materials with different composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, different from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity.

Figure 1

Antibacterial activity of the different pulp-capping materials evaluated by agar diffusion test. Each paper disk impregnated with the different pulp-capping materials was placed on agar plates previously incubated with the indicated streptococcal strains and incubated at 37°C for 24 h. The positive control was represented by a 10% dilution of 30% H₂O₂. All the assays were conducted in triplicate and the results were recorded in terms of the average diameter of inhibition zone (mm). Error bars indicate standard errors of the means.

Figure 2

MDPC-23 cells cytocompatibility of the different pulp-capping materials using the Transwell method. MDPC-23 cells were incubated with the different pulp-capping materials at 37°C for 24 h, 48 h, and 72 h in a Transwell culture plate as reported in Materials and Methods Section. The cell viability was assessed with MMT test. The data are presented as percent of the control incubated in absence of any materials and set as 100%. Five replicates for each pulp-capping material were used for each experiment performed in duplicate. Error bars indicate standard errors of the means.

Figure 3

CLSM images of apoptosis assay. MDPC-23 cells were cultured in a 24-Transwell-tissue culture plate for 24 h at 37°C in the absence of any material (a) or in the presence of H₂O₂ (b), MTA Angelus (c), Biodentine (d), Calcicur (e), Calcimol LC (f), Dycal (g), and TheraCal LC (h). PSVue480 reagent was used for staining apoptotic cells. CLSM images were taken at 20x magnification.