An alternative hypothesis to the cause of pulpal inflammation in teeth treated with phosphoric acid on the dentin.

This paper explores the possibility that the inflammatory response in pulpal tissues noted in some early studies when dentin was treated with phosphoric acid was not caused by the acid. It suggests that the inflammatory response was caused by the prolonged exposure to zinc oxide-eugenol and documents many reports that show ZOE to be a relatively toxic material. The paper also suggests that biocompatibility studies as performed today may be inappropriate.