BMP Gene-Immobilization to Dental Implants Enhances Bone Regeneration.

For individuals who have experienced tooth loss, dental implants are an important treatment option for oral reconstruction. For these patients, alveolar bone augmentation and acceleration of osseointegration optimize implant stability. Traditional oral surgery often requires invasive procedures, which can result in prolonged treatment time and associated morbidity. It has been previously shown that chemical vapor deposition (CVD) polymerization of functionalized [2.2]paracyclophanes can be used to anchor gene encoding vectors onto biomaterial surfaces and local delivery of a bone morphogenetic protein (BMP)-encoding vector can increase alveolar bone volume and density in vivo. This study is the first to combine the use of CVD technology and BMP gene delivery on titanium for the promotion of bone regeneration and bone to implant contact in vivo. BMP-7 tethered to titanium surface enhances osteoblast cell differentiation and alkaline phosphatase activity in vitro and increases alveolar bone regeneration and % bone to implant contact similar to using high doses of exogenously applied BMP-7 in vivo. The use of this innovative gene delivery strategy on implant surfaces offers an alternative treatment option for targeted alveolar bone reconstruction.

Three-Dimensional Volumetric Analysis of the Palatal Donor Site Following Soft Tissue Harvesting.

Autogenous soft tissue grafting is a commonly performed procedure in periodontal and implant surgery. Reharvesting a connective tissue graft (CTG) from the same palatal donor site is often required, but little is known about the volumetric changes that occur after harvesting a free gingival graft and how long the palatal mucosa takes to regain its original form and thickness. This study evaluated the volumetric changes that occur at the palatal donor site after harvesting a soft tissue graft with a noninvasive digital technology. Nineteen patients needing a CTG for a single site were enrolled. Intraoral digital scans of the palatal donor sites were obtained at baseline and at 1, 3, 6, and 12 months. The digital scans were imported and analyzed with an imaging software to evaluate volumetric changes. Average volume losses of 5.82 ± 2.63 mm3 and 11.03 ± 5.47 mm3 were observed after 1 and 3 months, respectively. Only minor changes were observed at 6 and 12 months. Linear dimensional changes at 5 and 7 mm from the gingival margin were substantially higher than the changes at 3 mm for the 1- and 3-month interval comparisons compared to baseline. Graft dimension was associated with volume loss at 1 and 3 months (P < .01). After palatal harvesting, the donor site undergoes volumetric changes, mostly during the first 3 months, and is attenuated thereafter.

Sclerostin antibody stimulates periodontal regeneration in large alveolar bone defects.

Destruction of the alveolar bone in the jaws can occur due to periodontitis, trauma or following tumor resection. Common reconstructive therapy can include the use of bone grafts with limited predictability and efficacy. Romosozumab, approved by the FDA in 2019, is a humanized sclerostin-neutralizing antibody (Scl-Ab) indicated in postmenopausal women with osteoporosis at high risk for fracture. Preclinical models show that Scl-Ab administration preserves bone volume during periodontal disease, repairs bone defects surrounding dental implants, and reverses alveolar bone loss following extraction socket remodeling. To date, there are no studies evaluating Scl-Ab to repair osseous defects around teeth or to identify the efficacy of locally-delivered Scl-Ab for targeted drug delivery. In this investigation, the use of systemically-delivered versus low dose locally-delivered Scl-Ab via poly(lactic-co-glycolic) acid (PLGA) microspheres (MSs) was compared at experimentally-created alveolar bone defects in rats. Systemic Scl-Ab administration improved bone regeneration and tended to increase cementogenesis measured by histology and microcomputed tomography, while Scl-Ab delivered by MSs did not result in enhancements in bone or cemental repair compared to MSs alone or control. In conclusion, systemic administration of Scl-Ab promotes bone and cemental regeneration while local, low dose delivery did not heal periodontal osseous defects in this study.

Ridge preservation of compromised extraction sockets applying a soft cortical membrane: A canine proof-of-principle evaluation.

OBJECTIVES: To explore whether placement of a soft cortical membrane can restore and regenerate the original alveolar ridge contour in deficient sockets. MATERIALS AND METHODS: One Beagle dog was used in this proof-of-principle evaluation. In a first intervention, a standardized buccal dehiscence defect was artificially created at the distal roots of the 3rd and 4th mandibular premolars. Four weeks later, following endodontic treatment of the mesial roots, teeth were hemisected and the distal roots were extracted without raising a flap. A cortical membrane (Lamina®, Osteobiol) was placed outside of the bony envelope of the extraction socket to rebuild the buccal bone contour. Afterwards, sockets were filled with a collagen-modified porcine bone graft material (Gen-Os®, Osteobiol) to the level of the surrounding bone height. The socket orifice was closed with a porcine dermal matrix (Derma®). After four months, block specimens containing the socket-sites and remaining roots were retrieved, histologically processed and analyzed. RESULTS: Surgery and post-operative healing were uneventful. Histologically, bone formation under the membrane was found, i.e. bony protrusions and ossicles by osteoblasts could be identified. Concomitantly, the membrane showed clear signs of degradation. Bone substitute was well integrated in newly formed bone and resorption of particles was found. CONCLUSION: Three major observations were made in the present proof-of-principle study: (i) regeneration of a compromised socket seems possible when applying the presented approach, (ii) the soft cortical membrane was sufficiently stable to allow for the establishment of the contour and to inhibit soft tissue invasion and (iii) the applied xenogenic graft material was undergoing remodelling processes while allowing adequate bone regeneration.