Comparison of the biocompatibility between 2 endodontic filling materials for primary teeth

The most-popular root canal filling materials for primary teeth are zinc oxide eugenol (ZOE), iodoform paste, and calcium hydroxide. Root canal filling materials need to be biocompatible with the periapical tissue. There are few papers which indicate the mechanism of cellular change of root canal filling materials. The purpose of the present study was to evaluate the cellular changes of a ZOE with formocresol (FC) and Vitapex-treated human osteosarcoma cell line. The ZOE powder mixed with the FC liquid and Vitapex alone were eluted in culture medium. The elution solutions were used to treat the human osteosarcoma cell line. The MTT assay was used to investigate the survival rate of U2OS cells. Western blot assay was used to compare the c-jun N terminal kinase (JNK) expression. One way ANOVA was used to compare the survival difference with p < 0.05 accepted as statistically significant. The result showed that the ZOE sealer was toxic to U2OS cells (p < 0.05). Vitapex was biocompatible with U2OS cells. JNK kinase expression was seen only in the ZOE with FC group. We concluded that ZOE with FC is not biocompatible with U2OS cells, and cell death occurred by apoptosis. Clinically, we suggest that Vitapex is a good choice for a primary tooth root canal filling material. (Chin Dent J, 24(1):28-34, 2005)