Biocompatibility Of CaO/ZnO Core-shell Structured Nanomaterial

A root canal sealer is to bond dentin with root canal filling material,eliminate dead space within the root canal and seals the whole system.However, its dissolution and degradation products may pass thorough dentinal tubules, lateral canals and accessory root canals and be long-term exposed to the periradicular tissue. A less biocompatible root canal sealer may destroy the periapical tissue or even cancerate surrounding cells.Local tissue reactions caused by sealers will also affect the final effect of root canal treatment. Main parameters to evaluate the biocompatibility includes genetic toxicity, mutagenicity, carcinogenicity, cytotoxicity and microbial reactions.The size of each CaO/ZnO core-shell structured nanosphere which is prepared in former experiment is among 80-300 nm, far less than the diameter of dentinal tubules(0.9-2.5μm). So the material can make a direct contact with periapical tissue. The nanospheres can release Ca2+and OH- and elevate ambient pH value. A higher pH value may activate the enzyme such as alkaline phosphatase and resulting in mineralization.That means CaO/ZnO core-shell structured nanosphere may has superior clinical value. This experiment compared cytotoxicity of Ca O/ZnO core-shell structured nanosphere with two other commonly used root canal sealers, to investgate its biocompatibility, and hoped to lay a theoretical foundation for its farther application.This experiment select two most commonly used root canal sealers Cortisomal, a zinc oxide-eugenol paste and AH plus, an epoxy resin sealer as control groups. The conclusion is the cytotoxicity of all root canal sealers increased with the extract concentration increased or time passed; there is no significant difference in cytotoxicity between CaO/ZnO core-shell structured nanosphere and the zinc oxide-eugenol root canal sealer(p ﹥ 0.05), and a strong cytotoxicity compared to the resin root canal sealer AH plus(p﹤0.05).