Methods: The experimental cement used consisted of 75 wt% Portland cement, 25 wt% bismuth oxide. Thirty five Sprague Dawley rat were used in this study. For the tissue reaction study, each material was implanted subcutaneously. Four weeks later, histologic process was performed. Inflammatory response was evaluated microscopically. A Kruskal-Wallis test was carried out to determine the significant difference for the inflammatory response of the test materials (p < 0.05).
Class V cavities were prepared on the right first molar and pulp exposures were capped with each materials. Four weeks later, the pulpal reaction to the material was evaluated by histologically.
Results: The tissue reaction to MTA was similar to that of the Portland cement and experimental cement. Statistical analysis of the inflammatory reaction revealed no significant difference between the experimental groups (p < 0.05).
The pulpal reaction to MTA, Portland cement and experimental cement was very similar. The prepared teeth, which were capped with each material, formed a hard tissue bridge. No inflammatory reaction was observed under the dentin bridge.
Conclusion: The tissue reaction and pulpal reaction of the experimental cement, which was made by adding bismuth oxide to Portland cement, was similar to MTA. These results suggest that the experimental cement may be a substitute for MTA. However, further studies will be needed to determine the suitability of Portland cement mixed with bismuth oxide for clinical use.