COMPARISON OF CANINE AND NONHUMAN PRIMATE ANIMAL-MODELS FOR PERIODONTAL REGENERATIVE THERAPY - RESULTS FOLLOWING A SINGLE ADMINISTRATION OFPDGF IGF-I

TWO COMMONLY USED ANIMAL MODELS for evaluating putative periodontal re generative therapies are the beagle dog model with natural periodontal disease and the non-human primate with ligature-induced attachment lo ss. The host response, microbiology, and skeletal rates of remodeling of these two models are summarized. In addition, the results of experi ments comparing the healing response to periodontal surgery with and w ithout concurrent use of the combination of platelet-derived growth fa ctor (PDGF) and insulinlike growth factor-I (IGF-I) in these models ar e presented. At 1 month, PDGF/IGF-I administration resulted in a 64.1% and 51.4% increase in new attachment formation in the non-human prima te and canine, respectively, while controls (surgery plus placebo) dem onstrated 34.1% and 8.6% increases in new attachment formation in the non-human primate and canine models, respectively. Further, applicatio n of PDGF/IGF-I stimulated 21.6% and 65% osseous defect fill in the no n-human primate and canine, respectively, while controls demonstrated 8.5% and 14.5% osseous defect fill in the non-human primate and canine , respectively. The osseous response in the canine appears greater tha n that of the non-human primate, and the new attachment formation was more substantial in the non-human primate than the canine. However, in general these data demonstrate a high degree of consistency in the ef fects of PDGF/IGF-I in promoting periodontal regeneration. Positive re sults in these two models-the dog with natural periodontal disease and the non-human primate with ligature-induced attachment loss-justify h uman clinical trial testing of a putative regenerative therapy.