Effect of Flowable Composite Resin on Cell Viability of Balb/c 3T3 Cells

大阪歯科大学Osaka Dental University博士（口腔科学）The flowable composite resins have been routinely used in recent clinical den-tistry. However, few studies have investigated the biological influence of flowable composite resins commercially available in Japan. In this study, we compared cell viability among 5 products currently available in dental clinical practice. Using mouse-derived Balb/c 3T3 cells, DMEM containing 5% fetal calf serum was adopted as an assay medium. Initially, the flowable resins were dissolved in the assay medium in the presence of dimethyl sulfoxide (DMSO) be-fore photopoly-merization, and each solution was diluted multiple times to investigate cell viability. As a result, all products showed cell death at a dilution ratio of 2. At a dilution ratio of 4 or 8, there was a marked decrease in cell viability. At a dilution ratio of 16, Subsequently, cell viability tests after photopolymerization were performed. Sam-ples were irradiated with an LED-type light irradiator for 5 or 10 seconds, and cell viability was investigated using the three-dimensional culture method with colla-gen. Cell viability was evaluated using MTT assay. Cell viability in the 10-second irradiation group for all products was higher than in the 5-second irradiation group. Some products showed no significant difference in comparison with the negative control group. There was no relationship between the monomer composition or filler type of any product and cell viability. The results of this study showed that cell viability slightly differed among the 5 clinically available products. There was no product for which cell viability was particularly low.doctoral thesi

上部構造と天然歯間のコンタクト離開に咬合が及ぼす影響についての横断調査

大阪歯科大学Osaka Dental University博士（歯学）Purpose: We investigated the relationship between occlusion and interproximal contact loss (ICL) by analyzing occlusal force and load distribution on adjacent teeth (AT) in 144 patients with implant-supported restorations (ISR) and no periodontal disease. ICL was defined as the ability to insert a 110 µm contact gauge without resistance. Methods: Using an occlusal force measurement system, we assessed total occlusal force, force on AT and ISR, and load distribution across the occlusal surface. Results: The ICL incidence was 21.2%, with the highest prevalence when occlusal loads were concentrated distally side on mesial AT. Conclusion: Our findings suggest that distal load concentration on mesial AT contributes to ICL, highlighting the importance of load distribution in preventing ICL in patients with ISR.doctoral thesi

脱分化脂肪細胞から作製した 3D スフェロイドの骨再生

大阪歯科大学Osaka Dental University博士（歯学）Aim: Dedifferentiated fat (DFAT) cells, similar to mesenchymal stem cells (MSCs), are gaining attention owing to their minimally invasive nature. We aimed to evaluate the effects of 3D DFAT spheroids on bone regeneration by implantation into rat skull defects. Methods: Adipose tissue was harvested from 8-week-old Sprague–Dawley rats, and DFAT was prepared using the ceiling culture method. DFAT was seeded onto threedimensional (3D) culture plates to produce spheroids, enhance cellular interactions, and mimic the in vivo environment. Bone defects were created on the skulls of 15-week-old rats using a 6.0-mm trephine burr. Collagen sponges were transplanted as controls, and 3D DFAT spheroid-seeded sponges were used in the experimental group. Results: DFAT showed a fibroblast-like morphology. Flow cytometry revealed that DFAT expressed MSC markers but not hematopoietic stem cell markers. Bone analysis revealed increased bone mineral density, volume, and trabecular thickness in the experimental group. Hematoxylin–eosin staining in the control group revealed only a thin layer of fibrous tissue, whereas the experimental group showed new bone tissue formation. The control group lacked Von Willebrand factor (vWf) expression, whereas the experimental group exhibited vWf expression, indicating the development of new blood vessels. Von Kossa staining revealed calcification only in the experimental group. Conclusion: Spheroids alone are difficult to retain in bone defects, making their use in combination with collagen sponges more effective for bone regeneration. The study findings suggest that 3D DFAT spheroids may help regenerate rat skull defects, with potential implications for human bone regeneration.doctoral thesi

Effect of diamond-like carbon thin-film deposition on the hardness of pure titanium surfaces.

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Effect of xanthan gum-based, guar gum-based, and starch-based thickeners on tongue pressure and pharyngeal residue.

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Beneficial outcomes of immunoenhancing nutritional interventions in perioperative care for oral cancer: a systematic review and meta-analysis.

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Analysis of the impact of periodontal disease management before the onset of type 2 diabetes mellitus on medical costs using administrative claims database.

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ゼラチン不織布を用いた間質細胞由来因子-1の徐放化による骨再生挙動の解析

大阪歯科大学Osaka Dental University博士（歯学）doctoral thesi

家兎下顎骨におけるインプラント周囲骨欠損のクリティカルサイズについて

大阪歯科大学Osaka Dental University博士（歯学）Background The mandible of the rabbit is considered a reliable model to be used to study bone regeneration in defects. The aim of the present study was to evaluate the formation of new bone around implants installed in defects of either 5 or 10 mm in the mandible of rabbits. Materials and methods In 12 rabbits, 3 mm deep circumferential defect, either 5 or 10 mm in diameter, were prepared bilaterally and an implant was placed in the center. A collagen membrane was placed to close the entrance. After 10 weeks, biopsies were taken, histological slides were prepared, and different regions of the defects were analyzed. Results Similar amounts of new bone were found in both defects. However, most of the 5 mm defects were filled with new bone. New bone was observed closing the entrance of the defect and laid onto the implant surface. Only in a few cases the healing was incomplete. Despite a similar percentage of new bone found within the 10 mm defects, the healing was incomplete in most of the cases, presenting a low rate of bone formation onto the implant surface within the defect. Only one case presented the closure of the entrance. Conclusions The dimensions of the defect strongly influenced the healing so that a circumferential marginal defect of 10 mm around an implant in the mandible body should be considered a critical-sized defect. The presence of the implant and of residues of teeth might have strongly influenced the healing.doctoral thesi

リハビリテーション病院高齢入院患者における咀嚼能力低下に関連する要因の検討

大阪歯科大学Osaka Dental University博士（口腔科学）This study quantitatively and qualitatively clarified the changes in oral function, focusing on masticatory function, from the period of daily life to the time of hospitalization. This study included elderly patients aged 65 years who consumed three meals orally and were being treated in the rehabilitation ward of Wakakusa Tatsuma Rehabilitation Hospital. We conducted a survey on eating habits and oral function at admission and investigated factors related to masticatory ability. Statistical analysis was performed using logistic re-gression analysis and quantification theory III. Logistic regression analysis revealed a significant association between masticatory ability and BMI, ODK/pa/, number of occlusal teeth, and number of hospitalizations to date. Quantification theory III revealed that changes in subjective oral function, relationship with society and medical care, and changes in the oral environment and function associated with hospitalization were related to masticatory ability. The number of teeth present and the duration of hospitalization were related to masticatory ability. These findings indicate that masticatory ability is as-sociated with oral health history and social and medical involvement. Its decline is asso-ciated with changes in oral environment and function due to hospitalization, reduced appetite and decreased food intake. Additionally masticatory ability affects physical function.doctoral thesi