Background: Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) technologies have been shown to significantly support alveolar bone formation. Biomaterial limitations, however, have restricted the biologic potential for onlay indications. The objective of this study was to evaluate regeneration of alveolar bone and periodontal attachment, and biomaterials reaction following surgical implantation of a spaceproviding, bioabsorbable, macroporous, polyglycolic acid‐trimethylene carbonate (PGA‐TMC) membrane combined with a rhBMP‐2 construct in a discriminating onlay defect model.Methods: Routine supraalveolar periodontal defects were created at the mandibular premolar teeth in 9 beagle dogs. Contralateral jaw quadrants in subsequent animals were randomly assigned to receive the domeshaped PGA‐TMC (100 to 120 μm pores) membrane with rhBMP‐2 (0.2 mg/mL) in a bioresorbable hyaluronan (Hy) carrier or the PGA‐TMC membrane with Hy alone (control). The gingival flaps were advanced to submerge the membranes and teeth and sutured. Animals were euthanized at 8 and 24 weeks postsurgery for histologic observations.Results: Jaw quadrants receiving the PGA‐TMC membrane alone experienced exposures at various time points throughout the study. Jaw quadrants receiving the PGA‐TMC/rhBMP‐2 combination remained intact, although one site experienced a late minor exposure. Newly formed alveolar bone approached and became incorporated into the macroporous PGA‐TMC membrane in sites receiving rhBMP‐2. The PGA‐TMC biomaterial was occasionally associated with a limited inflammatory reaction. Residual PGA‐TMC could not be observed at 24 weeks postsurgery. Residual Hy could not be observed at any time interval. Regeneration of alveolar bone height (means ± SD) was significantly increased in sites receiving the PGA‐TMC/rhBMP 2 combination compared to control (3.8 ± 1.3 versus 0.7 ± 0.5 mm at 8 weeks and 4.6 ± 0.8 versus 2.1 ± 0.4 mm at 24 weeks; P <0.05). Limited cementum regeneration was observed for PGA‐TMC/rhBMP‐2 and PGA‐TMC control sites. Ankylosis compromised regeneration in sites receiving PGA‐TMC/rhBMP‐2.Conclusions: The bioabsorbable, space‐providing, macroporous PGA‐TMC membrane appears to be compatible biomaterial for bone augmentation procedures. rhBMP‐2 significantly enhances alveolar bone augmentation and soft tissue healing when combined with the PGA‐TMC membrane. J Periodontol 2003; 74:635‐647.

Tissue occlusion does not appear to be a critical determinant for GTR. However, tissue occlusion may be a requirement for optimal GTR. Moreover, macroporous space-providing devices may increase the predictability of clinical GTR therapy.

rhBMP-2 adsorbed onto TPO implant surfaces initiates dose-dependent peri-implant bone re-modelling resulting in the formation of normal, physiologic bone and clinically relevant osseointegration within 8 weeks.

We conclude that the TO surface exhibits osteoconductive properties exceeding that of the CP surface. One or several of the chemical and physical properties of the TO surface may result in the remarkable bone formation along its surface. This study indicated that crystallinity and/or chemistry may be important.

Background and Objective In health, the periodontal ligament maintains a constant width throughout an organism’s lifetime. The molecular signals responsible for maintaining homeostatic control over the periodontal ligament are unknown. The purpose of this study was to investigate the role of Wnt signaling in this process by removing an essential chaperone protein, Wntless (Wls) from odontoblasts and cementoblasts, and observing the effects of Wnt depletion on cells of the periodontal complex. Material and Methods The Wnt responsive status of the periodontal complex was assessed using two strains of Wnt reporter mice, Axin2LacZ/+ mice and Lgr5LacZ/+. The function of this endogenous Wnt signal was evaluated by conditionally eliminating the Wntless (Wls) gene using an Osteocalcin Cre driver. The resulting OCN-Cre;Wlsfl/fl mice were examined using micro-CT and histology, immunohistochemical analyses for Osteopontin, Runx2 and Fibromodulin, in situ hybridization for Osterix, and alkaline phosphatase activity. Results The adult periodontal ligament is Wnt responsive. Elimination of Wnt signaling in the periodontal complex of OCN-Cre;Wlsfl/fl mice results in a wider periodontal ligament space. This pathologically increased periodontal width is due to a reduction in the expression of osteogenic genes and proteins, which results in thinner alveolar bone. A concomitant increase in fibrous tissue occupying the periodontal space was observed along with a disruption in the orientation of the periodontal ligament. Conclusion The periodontal ligament is a Wnt dependent tissue. Cells in the periodontal complex are Wnt responsive and eliminating an essential component of the Wnt signaling network leads to a pathological widening of the periodontal ligament space. Osteogenic stimuli are reduced and a disorganized fibrillary matrix results from depletion of Wnt signaling. Collectively, these data underscore the importance of Wnt signaling in homeostasis of the periodontal ligament.