Use of primates for wear testing of dental restorative materials

The mechanical loss of substance, both of teeth and man-made materials used to fill or replace teeth, principally occurs by attrition (the grinding of one tooth against another) or abrasion due to coarse particles present in the diet, dentifrices, or as products of the grinding itself. Nonhuman primates often have pronounced grinding or bruxing habits that serve to sharpen the teeth. Papio anubis baboons were used as a model to study the ability of teeth and restorative materials to withstand continual two- or three-body wear. One test site used the mandibular first premolars, occluding with the maxillary canines. For other studies, fixed appliances were cemented to the upper and lower incisors allowing placement of materials. Periodically, replica models of the surfaces were made for examination in a scanning electron microscope. Detailed descriptions of the morphological changes and/or failure of the materials appear elsewhere. It was found that the nonhuman primate model provides a rapid test of physiologic and pathologic wear of dental materials. It differs from the human situation only in the lack of good oral hygiene and the absence of extremes of thermal variations.