A laboratory evaluation of cell viability, radiopacity and tooth discoloration induced by regenerative endodontic materials

Aim To analyse the cytotoxicity, colour change and radiopacity of MTA Flow (MTA), UltraCal XS (UC) and Bio‐C Temp (BT). Methodology Human dental pulp cells (hDPCs) stimulated with lipopolysaccharide (LPS) were placed in contact with several dilutions of culture media previously exposed to the experimental materials and tested for cell viability using MTT. Bovine teeth were prepared to simulate an open apex and to mimic extensive crown fracture. The roots were filled with a mixture of agar and blood, and the materials placed over this mixture. The control group consisted of teeth filled only with agar and blood. Colour assessment analyses were performed before and immediately after material insertion and repeated at 30, 45 and 60 days using a spectrophotometer. The total colour change (ΔEab, ΔE00 and whiteness index (WI)) was calculated based on the CIELAB colour space. Digital radiographs were acquired for radiopacity analysis. Cell viability was analysed by one‐way anova, whilst differences in colour parameters (ΔEab, ΔE00 and WI) were assessed by two‐way repeated measures anova (α = 0.05). Tukey's test was used to compare the experimental groups, and Dunnett’s test was used to compare the experimental groups with the control group. Results MTA, UC and BT had similar cell viability to that of the control group (DMEM) (P > 0.05), except for the BT group at the 1 : 1 and 1 : 2 dilutions, which had significantly lower viability (P