The use of rhBMP2 for augmentation of established horizontal/vertical defects may require additional use of rhVEGF to achieve significant bone regeneration: An in vivo experimental study.

AIM: To test the hypothesis that the use of rhBMP2 in established defects requires additional growth factors such as rhVEGF to accomplish effective bone repair. MATERIALS AND METHODS: Horizontal/vertical defects of 2 cm length and 1 cm height were created bilaterally in the alveolar crest of the maxillae of 18 minipigs together with the extraction of all premolar teeth and one molar tooth on both sides. After 3 months of healing, defects were augmented with 0.5 g particulate PDLLA/CaCO3 composite loaded with 400 µg rhBMP2/50 µg rhVEGF165 on one side and 800 µg rhBMP2 on the other in 12 test animals, whereas defects in six control animals were sham operated and left unfilled on one side and augmented with blank carriers on the other. After 4 and 13 weeks, the animals were evaluated each for area of new bone formation (mm²) and bone density (area %). RESULTS: Augmentations with carriers loaded with 800 g µrhBMP2 failed to induce significantly more bone than in the augmentations with unloaded carrier after 4 and 13 weeks (p = .1000, p = .381). Augmentations with carriers loaded with 400 µg rhBMP2 and 50 µg erhVEGF165 resulted in significantly increased bone formation after 13 weeks (p = .024) compared to blank carriers. Soft tissue in augmentations with combined rhBMP2/rhVEGF165 loading exhibited numerous microvessels compared to soft tissue in augmentations with rhBMP2. CONCLUSIONS: It is concluded that effective bone regeneration in augmentations of established alveolar ridge defects may require the application of rhVEGF additionally to rhBMP2.

Accuracy of Navigation-Guided Dental Implant Placement with Screw Versus Hand Template Fixation in the Edentulous Mandible.

PURPOSE: Preoperative planning of the implant position as part of a coordinated prosthetic and surgical concept is becoming increasingly important regarding function and esthetics. The aim of this study was to investigate the transmission accuracy of template fixation during surgery in edentulous arches with hand fixation in comparison to intermediary screw fixation. MATERIALS AND METHODS: Preoperatively, 10 implant positions were planned using computed tomography (CT) with the system med3D for implant placement in four mandible models of the Goettingen study model, using a prosthetic diagnostic template. A total of 40 implant insertions were created. For every 20 insertions, the template was temporarily fixed with three screws and compared with the insertion using a hand-fixed template. The precision of the transmission was evaluated with and without screw fixation by re-evaluating the preimplant planning with additional CT scanning of the respective models. RESULTS: Compared with the hand-fixed procedure (HFG) in the model situation, there were no significant differences between the deviations of planned and final implant position in the screw-fixed group (FG). According to the study results, the fixed procedure leads to less depth deviation and lateral error of the implant base in relation to the HFG. Within both groups, there were significant differences between the radial deviation tendencies from the implant base to the implant apex (P = .033 for FG and P = .001 for HFG). CONCLUSION: The use of CT-based implant planning succeeds in fixed and hand-fixed surgical procedures with high precision in the atrophic, edentulous mandible model. According to the results of this study, in cases demanding high depth precision, screw-fixation of the template can be helpful.

Repair of large saddle defects of the mandibular ridge using dual growth factor release-An experimental pilot study in minipigs.

AIM: To test the hypothesis that the addition of small amounts of rhVEGF to rhBMP2 in a polymer carrier can accomplish equivalent repair effect as a reduced dosage of rhBMP2 compared to rhBMP2 alone. MATERIALS AND METHODS: Defects were created bilaterally in the mandibles of 18 minipigs. In 12 test animals, defects were filled with 0.5 g particulate PDLLA/CaCO3 composite loaded with 400 µg rhBMP2/50 µg rhVEGF165 on one side and 800 µg rhBMP2 on the other. After 4 and 13 weeks, the animals were evaluated each for area of new bone formation (mm²) and bone density (area %). RESULTS: Area of newly formed bone was higher in defects with carriers loaded with 400 µg rhBMP2 50 µg VEGF165 than in defects with 800 µg rhBMP2 after 4 weeks (11.97 versus 7.97 mm²; p = 0.043) and 13 weeks (72.48 versus 62.2 mm²; p = .028). Defects filled with blank carrier exhibited less bone after 13 weeks (42.75 mm²; p = .039 and .020 respectively). CONCLUSIONS: Delivery of rhBMP2 from a polymer carrier can improve repair of large saddle defects of the mandibular ridge. Addition of small amounts of rhVEGF can increase bone formation and at the same time reduce the dosage of rhBMP2.