Subcutaneous tissue reaction to castor oil bean and calcium hydroxide in rats

Castor oil bean cement (COB) is a new material that has been used as an endodonticsealer, and is a candidate material for direct pulp capping.

Objective

The purpose of this study was to evaluate the biocompatibility of a newformulation of COB compared to calcium hydroxide cement (CH) and a control groupwithout any material, in the subcutaneous tissue of rats.

Material and methods

The materials were prepared, packed into polyethylene tubes, and implanted in therat dorsal subcutaneous tissue. Animals were sacrificed at the 7th and 50th daysafter implantation. A quantitative analysis of inflammatory cells was performedand data were subjected to ANOVA and Tukey''s tests at 5% significance level.

Results

Comparing the mean number of inflammatory cells between the two experimentalgroups (COB and CH) and the control group, statistically significant difference(p=0.0001) was observed at 7 and 50 days. There were no significant differences(p=0.111) between tissue reaction to CH (382 inflammatory cells) and COB (330inflammatory cells) after 7 days. After 50 days, significantly more inflammatorycells (p=0.02) were observed in the CH group (404 inflammatory cells) than in theCOB group (177 inflammatory cells).

Conclusions

These results demonstrate that the COB cement induces less inflammatory responsewithin long periods.