Tooth slice organ culture for cytotoxicity assessment of dental materials

The purpose of this work was to develop a tooth slice organ culture method to assess the response of the cells of the dental pulp to commonly used dental materials and products. Wistar rat tooth slices were grown in culture for two and ten days in the presence of dental materials. After culture, the tooth tissues were processed and the responses of the pulpal cells were analysed histomorphometrically. Cytotoxic cell destruction was observed following the direct application of test materials to tooth slices ( n=298) after 10 days in culture (MANOVA, P=0.0001), whilst the restoration of prepared deep dentine cavities ( n=30), with test products, did not result in a significant amount of pulpal injury (MANOVA, P=0.287). In rank order of causing pulpal injury, the test materials from the most to the least cell destructive, was; Salicylic acid, Calcium hydroxide, Kalzinol zinc oxide eugenol, high-mercury Amalgam, Prime & Bond, Dycal, Barium sulphate, Hypocal, Scotchbond, Calasept, Life and One-step. Tooth slice organ culture, provided a cytotoxicity screening method for dental materials, bearing a closer physiological resemblance to the clinical situation than cell culture screening methods. Tooth slice culturing may have the potential to replace some types of in vivo animal experimentation, as there is a clear need to reduce this form of testing.