The Use of 3D Printed Tooth Preparation to Assist in Teaching and Learning in Preclinical Fixed Prosthodontics Courses.

Tooth preparation for fixed dental prostheses is not an easy procedure to understand spatially, especially for first-year dental students. This technical report describes an innovative technique for assisting learning in preclinical fixed prosthodontics courses. Ideal full-contour tooth preparations are digitally scanned and 3D printed to the exact specifications of the ideal preparation. Students and faculty use these printed tooth preparations as teaching and learning tools to facilitate in 3D visualization for fixed prosthodontics courses.

Mouse anti-RANKL antibody delays oral wound healing and increases TRAP-positive mononuclear cells in bone marrow.

OBJECTIVES: Denosumab, a human monoclonal antibody (mAb) that neutralizes receptor activator for nuclear factor κB ligand (RANKL), is associated with osteonecrosis of the jaw. However, the effect of denosumab on oral wounds is unclear. The aim was to determine the effect of anti-RANKL mAb on oral wounds and bone marrow. MATERIALS AND METHODS: The direct effect of the mAb on fibroblasts, macrophages, and osteoclasts were assessed in vitro. In vivo, mouse anti-RANKL mAb was administered to mice for 9 weeks prior to palatal bone denudation surgery. Mice were euthanized 3 weeks post-surgery, and wound healing was histomorphometrically analyzed. Long bones were assessed using micro-computed tomography, quantitative real-time polymerase chain reaction, and flow cytometry. RESULTS: The mAb had no effect on macrophages and fibroblasts but significantly suppressed osteoclast proliferation in vitro. The mAb treatment significantly increased bone mass by suppressing osteoclasts in vivo. The expression of pro-osteoclastic genes was promoted in the bone marrow of the mAb-administered animals. Consistently, the mAb significantly induced the development of tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells (MNCs) but not osteoclasts in bone marrow. The mAb treatment had no effect on gross healing of the palatal wounds. However, significant inflammation was retained in the connective tissue facing the once denuded bone surface. CONCLUSIONS: Repair of the damaged palate was delayed, and significant inflammation was sustained in the connective tissue by anti-RANKL mAb treatment. CLINICAL RELEVANCE: Denosumab impairs osteoclastic bone repair. Care should be exercised to minimize osseous trauma when invasive procedures are performed on patients taking denosumab.

Parathyroid hormone related to bone regeneration in grafted and nongrafted tooth extraction sockets in rats.

OBJECTIVE: The quality and quantity of bone formed in tooth extraction sockets impact implant therapy. Therefore, the establishment of a new approach to enhance bone formation and to minimize bone resorption is important for the success of implant therapy. In this study, we investigated whether intermittent parathyroid hormone (PTH) therapy enhanced bone formation in grafted sockets. METHODS: Tooth extractions of the maxillary first molars were performed in rats, and the sockets were grafted with xenograft. Intermittent PTH was administered either for 7 days before extractions, for 14 days after extractions, or both. The effect of PTH therapy on bone formation in the grafted sockets was assessed using microcomputed tomography at 14 days after extractions. RESULTS: PTH therapy for 7 days before extractions was not effective to augment bone fill, whereas PTH therapy for 14 days after operation significantly augmented bone formation in the grafted sockets. CONCLUSIONS: Intermittent PTH therapy starting right after tooth extractions significantly enhanced bone fill in the grafted sockets, suggesting that PTH therapy can be a strong asset for the success of the ridge preservation procedure.