Calcium and Hydroxide Release from Pulp-Capping-Materials and Temperature-Rise During Polymerization

The objective of this study was to evaluate the release of calcium-ions from different pulp-capping materials determine the pH changes at different time intervals and compare the temperature rise during polymerization.

Method: Three light-cured calcium-hydroxide containing materials (BinerLC, CalcimolLC, Ultra-Blend Plus), a light-cured resin-modified calcium-silicate filled material (TheraCalLC) and as a self-setting calcium-hydroxide containing material (Dycal) as a control group were used for evaluating calcium-hydroxide release. All materials were analzed after 3, 24, 72, 168, 336,672 hours. The release of calcium-ions and pH changes were measured using an atomic absorption spectrophotometer and a pH- meter, respectively. In order to evaluate temperature rise of light-cured materials during polymerization, pulpal circulation was simulated by water cycling through the pulp with a defined flow pressure to simulate the clinical case. For calcium release and pH changes, statistical evaluation was performed by means of Kruskal-Wallis and Mann-Whitney U test and thermal changes were analysed by one-way ANOVA and Tukey HSD tests (p<0.05).

Result:

TheraCalLC released the highest level of calcium-ions at 24 hours among all materials at all-time intervals. The lowest calcium-ions were released from BinerLC at all-time periods. While the TheraCalLC released highest calcium-ions at 3,24,72 hours, Dycal released  the highest calcium-ions at 168,336 and 672 hours among all materials. Whereas, there were statistically significant difference between pH values of Dycal and TheraCalLC at 72 and 672 hours, there were no statistically significant difference at other time intervals between these materials. The highest and the lowest temperature rises were for Ultra-Blend Plus and the TheracalLC, respectively. In all materials’ evaluation, while there was no significantly difference between BinerLC and Ultra-BlendPlus groups, there were statistically differences between all other groups.

Conclusion:

TheraCalLC is a promising material with its high pH level, releasing high calcium-ions and relatively lowest temperature rise during polymerization over deep cavities.