Physico-Chemical-Mechanical and Cytotoxicity Properties of Calcium-Phosphate Based Pulp Capping Agents

“Objectives: ” The properties of new calcium phosphate cements were compared with those of calcium hydroxide and Dycal cements in dental pulp-capping applications.“Methods: ” Monocalcium phosphate, calcium oxide, and synthetic hydroxyapatite, were combined with an aqueous solution of 35% w/w poly (methyl vinyl ether maliec acid). Calcium acetate and tartaric acid were mixed to make three different CPC’s: Calcium acetate 5% (w/w) was added to obtain CPC-1. Tartaric acid 10% (w/w) to make CPC-2 and both tartaric acid 10% (w/w) and calcium acetate 5% (w/w) to produce CPC-3. Two commercial cements calcium hydroxide (CH) and Dycal were selected as controls. Setting time, compressive strength, pH and solubility were evaluated. In vitro cytotoxicity of the three CPCs and commercial cements was assessed. Set cements were placed in cell culture in contact with pulp fibroblast cells for 72hr.  Cellular function was assessed using MTT assay. ”Results: ” CPC-1 showed an increase in SDH Activity by >87% relative to Teflon by the second week, followed by a relapse. CPC-2 suppressed SDH activity by >80% relative to Teflon by the third week and was equivalent to Teflon by the fourth week. CPC-3 was statistically equivalent (p> 0.05) to Teflon by the third week. Both Dycal and calcium hydroxide showed SDH suppression of 35 and 50% respectively after 4 weeks. Setting time of CPC-1 was equivalent to Dycal. Setting times of CPC-2 and CPC-3 were between Dycal (2 min 25 s) and CH (>60 min). There were significant (p< 0.05) statistical differences in compressive strength between CPC-1, CPC-3 and Dycal. There were no statistical differences in solubility between CPCs and Dycal (p > 0.05) after immersion for 24hr. For pH, significant differences were observed between CPCs, Dycal, and CH groups at different times. “Conclusion: ” These results suggest that CPC-2 and CPC-3 hold promise as dental pulp capping agents.