Comparison of the clinical and preclinical biocompatibility testing of dental materials: are the ISO usage tests meaningful?

Abstract

International Organization for Standardization (ISO 10993 and 7405) guidelines recommends the preclinical screening of dental materials using non-human primates. The literature contains no comparisons of responses to dental materials. To test the accuracy of preclinical screening tests for predicting human clinical responses, 106 class V pulp exposed cavities were prepared in human and non-human primate teeth. Teeth were restored with calcium hydroxide and amalgam, zinc oxide eugenol or resin-modified glass ionomer. Teeth were extracted after 10-163 days and prepared for histological analysis. Pulp cell numbers were compared and their reactionary dentin activity measured in response to cavity preparation. Pulp inflammatory activity was categorized according to ISO standards. There were no statistically significant differences between human and non-human primate teeth in terms of pulp reactions to dental materials. The use of non-human primates for preclinical biocompatibility investigation provided an accurate method of evaluating clinical responses to dental materials.