Investigation of calcium-silicate content and conversion degree of resin-based pulp capping materials

The present study aimed to measure the microstructure of the TheraCal LC (Bisco Inc., Schaumburg, IL) and Calciplus LC (Imicryl, Konya, Turkey) and to investigate the effect of excitation durations and different light sources on their 'degree of conversion' properties. Three excitation modes of the resinous pulp capping materials were tested at 5, 10, and 20-s: light-emitting diode, and near-infrared laser excitation at 532 and 785 nm wavelengths. Resinous materials and excitation durations factors were analyzed with the two-way ANOVA test and Tukey Post Hoc tests (alpha = 0.05). It is found that the near-infrared laser cannot polymerize the samples and TheraCal LC had greater mean values than Calciplus LC at 5, 10, and 20-s (p < 0.001, p = 0.011, and p = 0.062, respectively). Energy-dispersive X-ray spectroscopy and X-ray powder diffraction analysis were used to assess the calcium-silicate content. Calcium-silicate phases were observed in TheraCal LC but these phases did not exist in the Calciplus LC. TheraCal LC and Calciplus LC have similarities in their conversion degree properties with LED excitations at 20-s, however, the calcium-silicate content measured in the experiments is not in agreement with the data of the Calciplus LC declared by the manufacturer.