Newly formed cementum induced by the osteogenic proteins of the TGF-B supergene family

Abstract

Osteogenic proteins/ Bone morphogenetic proteins are soluble signals that have potent and pleiotropic functions which have enticed researchers to explore their role in periodontal regeneration. The potential of these proteins to induce cementum formation in a periodontal healing context has been previously demonstrated. However, is the ability to induce cementum uniformly applicable to different BMPs? Do some BMPs have more of a cementogenic effect than others? This study was designed to measure newly formed cementum induced by different osteogenic proteins of the transforming growth factor-ß supergene family. Material and Methods: Histological sections prepared from previous periodontal regeneration studies of surgically created furcation defects of 26 mandibular molar teeth of Papio ursinus, exposed to different applications of BMPs were assessed and compared. The BMPs used in these periodontal studies included recombinant human osteogenic protein-1 (hOP-1), recombinant human bone morphogenetic protein-2 (hBMP-2) , binary application of hOP-1 and hBMP-2, recombinant human transforming growth factor β₃ (hTGF-β₃), synergistic application of hTGF- β₃ and hOP-1 as well as naturally-derived BMPs. Histomorphometric measurements of the extent of cementum formation along the mesial and distal root surfaces were made. The thickness of newly formed cementum was measured in three regions along the root surface in apical, middle and coronal regions. Results: The BMPs which yielded the most favourable cementogenic outcome included hOP-1, hTGF-β₃ and the synergistic application of hOP-1 and hTGF-β₃. Naturally-derived highly purified BMPs and hOP-1 applications showed greater cementogenic effects with regards to the extent of cementum formed. Applications of hOP-1, hTGF-β₃ and the synergistic application of hOP-1 and hTGF-β₃ showed positive cementogenic effects with regards to the thickness of cementum formed along root surfaces. The hBMP-2 applications were found to be the least inductive category of BMPs in forming new cementum along the root surfaces, both in extent and thickness measurements.