ABSTRACT
The induction of cementogenesis with de novo generation of Sharpey’s bers inserting into newly formed cementum and beyond, into highly mineralized, almost impermeable dentine is a problem central to periodontal tissue regeneration. The molecular bases of such regeneration are the soluble molecular signals of the osteogenic proteins of the transforming growth factor-β (TGF-β) supergene family. In addition to the induction of bone formation per se, the osteogenic proteins of the TGF-β supergene family act as soluble molecular signals for the induction of periodontal tissue regeneration, sculpting the multicellular mineralized structures of the periodontal tissues with functionally
oriented periodontal ligament bers into newly formed cementum (Ripamonti 2007). Notably, 75 µg of hTGF-β3 in a growth factor-reducedMatrigel® matrix induces prominent cementogenesis, with cementoid matrix covered by cementoblasts when implanted in Class II furcation defects surgically constructed in mandibular molars of the non-human primate Chacma baboon (Papio ursinus). The newly formed periodontal ligament space is characterized by running bers tightly attached to the cementoid surface, penetrating as mineralized bers the newly formed cementum and inserting into dentine. Prominent angiogenesis characterizes the newly formed periodontal ligament space as induced by the hTGF-β3 isoform when implanted in Class II furcation defects of P. ursinus . Newly sprouting capillaries are lined by cellular elements with condensed chromatin, indicating the rapid and sustained induction of angiogenesis. Importantly, for tissue engineering in clinical contexts, the inductive activity of hTGF-β3 in Matrigel matrix is enhanced by the addition of autogenous morcellated fragments of rectus abdominis muscle, thus providing myoblastic, pericytic/perivascular stem cells for further tissue induction and morphogenesis by the hTGF-β3 isoform. In primates and in primates only, the mammalian hTGF-β isoforms are powerful inducers of endochondral bone formation. Doses of the hTGF-β3 osteogenic device when combined with either allogeneic insoluble collagenous bone matrix or growth factor-reduced Matrigel matrix as carrier induce regeneration of Class II and III furcation defects in P. ursinus (Ripamonti et al. 2009a; Ripamonti et al. 2009b; Ripamonti and Petit 2009).
