Biological parameters, discolouration and radiopacity of calcium silicate-based materials in a simulated model of partial pulpotomy.

Aim: To analyse the discolouration, radiopacity, pH and calcium ion release of Biodentine (BD), Bio-C repair (BCR) and Bio-C temp (BCT), as well as their biological effects on human dental pulp cells (hDPCs).

Methodology: Sixty-four extracted bovine incisors were prepared to simulate crown fractures with pulp exposure and open root apex. The roots were filled using a mixture of agar and blood (control), and BD, BCR or BCT were placed over this mixture. Colour assessment analyses of the samples were performed before and immediately after material insertion and repeated at 30 and 90 days, using a spectrophotometer. The colour change of each specimen was evaluated at the crown and calculated based on the CIELab colour space. Digital radiographs were acquired for radiopacity analysis. hDPCs were placed in contact with different dilutions of culture media previously exposed to such materials and tested for cell viability using the MTT assay. The pH and calcium ion release of all materials were measured after 24 h; the data were assessed using one-way analysis of variance (ANOVA). Cell viability was analysed by two-way ANOVA. Differences in colour parameters and wound-healing data were assessed by two-way repeated measures ANOVA (α = 0.05). Tukey's and Dunnett's tests were used to compare the experimental groups with the control group.

Results: BCR had grater radiopacity and smaller colour alteration (ΔEab/ΔE00) than the other materials tested (p < .005; p < .001). No significant differences in pH were found amongst the tested materials (p > .05). BCT was associated with the largest release of calcium ions (p < .0001). BD had cell viability similar to that of the control at the lowest dilutions, and BCR was similar to that of the control, regardless of the dilution tested (p > .05). BCT had a lower percentage of viability than that of the control at all tested dilutions (p < .0001). Cell migration rates in BD and BCR were similar to those in the control group after 24 h and 48 h (p > .05), whilst BCT had larger voids than the control in both periods (p < .0001).

Conclusions: BCR, BCT and BD were associated with tooth discolouration. BCR had the lowest staining values, the highest radiopacity and viability greater than 80% hDPCs.