Yoichiro Nakajima

Rapid and Easy Histological Evaluation of Alveolar Human Bone Quality at Dental Implant Sites Using a Nondecalcified Frozen Cryofilm Section Technique: A Technical Report.

Introduction:The evaluation of bone quality at the site of the alveolar bone for a dental implant is very important. This study presents an easy technique for direct evaluation of alveolar bone quality using nondecalcified cryofilm frozen sections on human alveolar bone core samples. Materials and Methods:Core samples harvested from alveolar bone were immediately frozen in cooled hexanen and slowly cut using a disposable tungsten carbide blade; the sliced sections were collected with adhesive cryofilms. Staining was performed using von toluidine blue and von Kossa for microscopic observations. Results:All core samples clearly showed bone structure components of cortical bone, trabecular bone, bone marrow, blood vessels, and bone-related cells. Conclusion:These results suggest the efficacy of a nondecalcified cryofilm frozen section technique for histological observation of surgical implant sites.

Osteogenic capacity of mixed-acid and heat-treated titanium mesh prepared by a selective laser melting technique

The practical use of additive manufacturing to create artificial bone as a material for repairing complex bone defects is currently attracting attention. In this study, we compared the osteogenic capacity of materials composited by the method developed by Kokubo et al. of treating 3D-printed titanium (Ti) mesh with a mixture of H2SO4 and HCl and heating (mixed-acid and heat treatment) with that of materials subjected to conventional chemical treatment. Ti plates treated with this method have been found to promote highly active bone formation on their surface when inserted into rabbit tibial bone defects. No previous study has compared this method with other surface treatment methods. In this study, we used histological and other observations to compare the bone formation process in bone defects when Ti meshes prepared by the selective laser melting technique (SLM) and treated either with mixed acids and heat or with conventional chemical Ti surface treatments were implanted in a rat calvarial bone defect model. We found that both micro-computed tomography and observations of undecalcified ground sections showed that the best bone formation was observed in rats implanted with mesh treated with mixed acids and heat. Our results suggest that mixed-acid and heat-treated Ti mesh prepared by SLM may have a high osteogenic capacity in bone defects.

Usefulness of oral administration of the specialized amino acid supplement consisting of β-hydroxy-β-methylbutyrate, L-arginine and L-glutamine (Abound™) for chronic soft tissue diseases in the mouth.

Background: Abound™ is a nutritional supplement containing β-hydroxy-β-methylbutyrate, Lglutamine, and L-arginine (HMB/Gln/Arg). In recent years, the effects of these nutrients in promoting wound healing have been reported. Here we report our experience of using this supplement for the treatment of chronic oral mucosal diseases. Methods： We clinically investigated the effects of HMB/Gln/Arg on 9 cases of chronic oral mucosal diseases such as oral lichen planus and recurrent aphthous stomatitis. Results: Improvement in subjective symptoms was observed in 7 out of 9 cases of oral mucosal diseases. Conclusion: We found that the use of this supplement was effective in the treatment of 7 out of 9 cases of chronic oral mucosal diseases. Thus, we believe that HMB/Gln/Arg use should be considered as a treatment option.