PERIODONTAL REPAIR IN DOGS - EFFECT OF RECOMBINANT HUMAN TRANSFORMINGGROWTH FACTOR-BETA(1) ON GUIDED TISSUE REGENERATION

This study evaluated alveolar bone and cementum regeneration following surgical implantation of recombinant human transforming growth factor -beta(1) (rhTGF-beta(1)) in conjunction with guided tissue regeneratio n (GTR). Supraalveolar, critical size, periodontal defects were surgic ally created around the 3rd and 4th mandibular premolar teeth in right and left jaw quadrants in 5 beagle dogs. Alternate jaw quadrants in c onsecutive animals received rhTGF-beta(1) in a CaCO3/ hydroxyethyl sta rch carrier with GTR, or carrier with GTR alone (control). 20 mu g of rhTGF-beta(1) in buffer solution was incorporated into approximately 0 .8 mi of carrier for each defect scheduled to receive rhTGF-beta(1). A nimals were sacrificed at week 4 postsurgery and tissue blocks were ha rvested and processed for histometric analysis. Clinical healing was g enerally uneventful. Minor membrane exposures were observed. Defects w ith membrane exposure displayed an inflammatory infiltrate underneath the membrane. Bone regeneration of trabecular nature, apparent in all animals, was generally limited to the very apical aspect of the defect s. Cementum regeneration was limited without obvious differences betwe en experimental conditions. Comparing rhTGF-beta(1) to control defects , statistically significant differences were found for area (1.8 +/- 0 .4 and 1.3 +/- 0.6 mm(2), respectively; p < 0.05) and density (0.3 +/- 0.1 and 0.2 +/- 0.03, respectively; p < 0.05) of alveolar bone regene ration. Observed differences are small and represent a clinically insi gnificant potential for enhanced regeneration in this preclinical mode l. Within the limitations of study, it may be concluded that rhTGF-bet a(1) has a restricted potential to enhance alveolar bone regeneration in conjunction with GTR.