Evaluation of the biocompatibility and discoloration potential of a novel radiopaque Portland cement formulation for dental application

This study compared the biocompatibility and discoloration potential of Malaysian Portland cement (MPC), experimental MPC (EPC), radiopaque nano-zirconium oxide modified EPC (REPC), with ProRoot white mineral trioxide aggregate (WMTA) using human dental pulp stem cells (HDPSCs) with/without lipopolysaccharide (LPS). Cytotoxicity and cell attachment were evaluated using MTT assay and scanning electron microscope (SEM) after 24/72 h. For discoloration, the cements were placed in extracted human permanent maxillary incisors and color was measured spectrophotometrically. Results showed that all extracts except 100 mg/mL were non-cytotoxic. For LPS-treated groups (24 h), WMTA demonstrated higher cell viability than REPC (p<0.008). At 72 h, all groups were comparable. At 24 h, LPS-treated HDPSCs exhibited lower values than untreated HDPSCs (p<0.008). At 72 h, differences were comparable. SEM demonstrated favorable HDPSCs attachment. Tooth discoloration was the highest for WMTA, and lowest for REPC. In conclusion, the biological properties of REPC were comparable with WMTA. REPC did not cause tooth discoloration.