Osaka Dental University Academic Repository / 大阪歯科大学学術リポジトリ
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ナノ構造処理した純チタン金属へのアルゴンガスプラズマ処理が生体適合性に与える影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）In this study, we applied argon plasma treatment to titanium surfaces with nanostructures deposited by concentrated alkali treatment and investigated the effects on the surface of the material and the tissue surrounding an implant site. The results showed that the treatment with argon plasma removed carbon contaminants and increased the surface energy of the material while the nanoscale network structure deposited on the titanium surface remained in place. Reactive oxygen species reduced the oxidative stress of bone marrow cells on the treated titanium surface, creating a favorable environment for cell proliferation. Good results were observed in vitro evaluations using rat bone marrow cells. The group treated with argon plasma exhibited the highest apatite formation in experiments using simulated body fluids. The results of in vivo evaluation using rat femurs revealed that the treatment improved the amount of new bone formation around an implant. Thus, the results demonstrate that argon plasma treatment enhances the ability of nanostructured titanium surfaces to induce hard tissue differentiation and supports new bone formation around an implant site.doctoral thesi
生体材料開発に向けた2型糖尿病ラットの抜歯後粘膜治癒過程における老化細胞の検出
Get PDF大阪歯科大学Osaka Dental University博士（歯学）The delayed mucosal healing of tooth extraction sockets in diabetes has few known effective treatment strategies, and its underlying mechanism remains unknown. Senescent cells may play a pivotal role in this delay, given the well-established association between diabetes, senescent cells, and wound healing. Here, we demonstrated an increase in p21- or p16-positive senescent cells in the epithelial and connective tissues of extraction sockets in type 2 diabetic rats compared to those in control rats. Between 7 and 14 d after tooth extraction, a decrease in senescent cells and improvement in re-epithelialization failure were observed in the epithelium, while an increase in senescent cells and persistence of inflammation were observed in the connective tissue. These results suggest that cellular senescence may have been induced by diabetes and contributed to delayed mucosal healing by suppressing re-epithelization and persistent inflammation. These findings provide new targets for treatment using biomaterials, cells, and drugs.doctoral thesi
成長期中国人のオトガイ部の形態学的研究
Get PDF大阪歯科大学Osaka Dental University博士（歯学）We used cephalograms to investigate the correlation between the craniofacial morphology and the mandibular symphysis in Chinese children, measuring the angles between the mandibular plane and symphysis, and the angles between the symphysis and mandibular central incisor. We observed the correlations in males with skeletal Class I between ∠SNA and Idm-Me (mm); between ∠SNB and Idm-Me (mm); between ∠ANB and ∠Idm-X to MP; between FMA and ∠Idm-Me to MP, ∠X-Me to MP, and Thickness Pogonion; between IMPA and ∠Idm-Me to MP, ∠Idm-X to MP, ∠X-Me to MP, and Thickness Pogonion; and between Gn-Cd and Idm-Me (mm), and Thickness Pogonion. In males with skeletal Class II, correlations were observed between ∠SNB and Thickness Pogonion; between ∠ANB and ∠Idm-Me to MP, and ∠L1 to X-Me; between FMA and ∠L1 to Idm-X, and ∠L1 to X-Me; between IMPA and ∠Idm-Me to MP, ∠Idm-X to MP, ∠X-Me to MP, ∠L1 to Idm-X, and ∠L1 to X-Me; and between Gn-Cd and Idm-Me (mm), Thickness Point B, and Thickness Pogonion. In females with skeletal Class I, correlations were observed between FMA and ∠X-Me to MP, ∠L1 to Idm-X, and ∠Thickness Pogonion; between IMPA and ∠Idm-X to MP, ∠X-Me to MP, and ∠L1 to X-Me; and between Gn-Cd and Idm-Me (mm), and Thickness Pogonion. In females with skeletal Class II, correlations were observed between ∠SNA and ∠Idm-Me to MP, ∠Idm-X to MP, and ∠X-Me to MP; between ∠SNB and ∠Idm-Me to MP, ∠Idm-X to MP, and ∠X-Me to MP; between FMA and ∠L1 to Idm-X, and Thickness Point B; between IMPA and ∠Idm-Me to MP, ∠Idm-X to MP, ∠X-Me to MP, ∠L1 to X-Me, and Thickness Point B; and between Gn-Cd and ∠L1 to X-Me, and Idm-Me (mm). These results suggested the importance of monitoring movement of the mandibular anterior teeth during orthodontic treatment because skeletal differences affect the inclination of these teeth and the morphology of the symphysis.doctoral thesi
水圧を用いた上顎洞底挙上術の安全性について-洞粘膜挙上モデルにおける実験的考察-
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Currently, studies on the safety of maxillary sinus floor elevation involving the application of water pressure to detach and elevate the sinus membrane are limited. In this study, we created an eggshell model to elevate the sinus membrane and evaluated its effects on the shape of the elevating part, and the effects of flow rate and the implementation of a starting point (SP) on the elevation; 12 groups were compared based on the combinations of the shape of the lifting part, presence or absence of SP, and flow rate (300, 600, 1200 mL/h). We visually observed the state of the eggshell membrane during lifting, and a pressure gauge was used to detect pressure changes. In the case of with SP, no significant difference was observed in shape or flow rate, and stable lifting was possible. In the case of without SP, the maximum pressure increased significantly (p < 0.05); however, no significant difference was observed in shape or flow rate. To safely and accurately elevate the sinus membrane using water pressure, bone morphology and flow rate are crucial factors. Additionally, implementing SP at the elevation site is essential.doctoral thesi
周術期口腔ケアに有用となる口腔フローラ解析法の開発
Get PDF大阪歯科大学Osaka Dental University博士（歯学）The relationship between overall health and the oral flora has become clear with the development of oral flora analysis using next-generation sequencing. Although Illumina (San Diego, CA, USA) sequencers are widely used for oral flora analysis, their short-read nature poses some limitations, such as the inability to distinguish closely related bacterial species. Recently developed, the nanopore sequencer offers rapidly improving sequencing accuracy. The technology can read the full 16S rRNA gene, which has the potential to provide higher resolution in oral flora analysis. In this study, we utilized Illumina and nanopore sequencing methods to analyze saliva and interdental flora from two healthy adults and compared the outcomes of oral flora analysis. QIIME2 pipeline was used for Illumina sequence reads, while EPI2ME or NanoCLUST was utilized for nanopore reads. There was disagreement between Illumina and nanopore in the results of the oral flora analysis. Certain species exhibited a significant bias in detection through one of the sequencing methods, likely as a result of differences in the amplified region of 16S rRNA and the PCR primer utilized. Our findings suggest that utilizing the nanopore sequencer offers benefits when detecting certain species. Furthermore, optimizing the primers used during PCR could improve detection of species underrepresented in the nanopore.doctoral thesi
お茶の種類と口腔残存歯数の関係：CLHLS調査の横断研究
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Previous studies have suggested that tea consumption may have a positive impact on oral health. However, the effects of different tea types on oral health remain unclear. Therefore, this study aimed to determine the association between residual teeth and consumption habits of different types of tea (green tea, black tea, oolong tea, and scented tea) in older adults.We conducted a secondary analysis using data from the Chinese Longitudinal Healthy Longevity Survey in 2018. In a sample of 6,387 older adults, we performed logistic regression analysis to examine the relationship between persistent tea consumption and oral health according to sex and brushing frequency. The indices for particularly healthy oral health and relative health were set at more than 20 teeth and more than 10 teeth, respectively.The study included 2,725 males and 3,662 females, both aged 65 and older. Among individuals with more than 20 teeth, drinking green tea significantly improved oral health in men (adjusted odds ratio [ORs]: 1.377; 95% confidence interval [CI]: 1.082–1.752) and drinking black tea significantly improved the oral health of women (ORs: 2.349, 95%CI: 1.028–5.366). In the daily brushing group, green tea had a significant beneficial effect on increasing the number of teeth in men and black tea had a significant beneficial effect in women. Among individuals with more than 10 teeth, drinking green tea significantly improved oral health in men (ORs: 1.539; 95% CI: 1.209–1.959) and drinking green tea and scented tea significantly improved the oral health of women (ORs: 1.447, 95%CI: 1.052–1.991; ORs: 1.948, 95%CI: 1.137–3.340). In the daily brushing group, consumption of green tea and black tea had significant beneficial effects on increasing the number of teeth in men, whereas that of green tea, black tea, and scented tea had significant beneficial effects in women.Long-term green tea consumption in males and black tea consumption in females were significantly associated with maintaining functional dentition (≥20 teeth). Similarly, long-term green tea consumption in males and green tea and scented tea consumption in females were associated with avoiding severe tooth loss (≥10 teeth). Furthermore, in the daily tooth brushing group, long-term consumption of black tea was associated with avoiding severe tooth loss in both sexes. However, tea consumption alone had no effect on oral health without good brushing habits.doctoral thesi
高出力赤色LEDを用いた光増感反応は活性酸素種の誘導により歯肉の創傷治癒を促進する
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Photodynamic therapy is a treatment that combines a light source with a photosensitizer. LEDs have attracted considerable attention in clinical dentistry because they are inexpensive and safe to use. Although the interaction between photosensitizers and LEDs in dental practice is effective for treating periodontal disease by killing periodontopathic bacteria, little is known about the effects of LEDs on human gingival fibroblasts (HGnFs), which play an important role in gingival wound healing. In this study, we investigated the effects of high-intensity red LED irradiation on HGnFs after the addition of methylene blue (MB), one of the least harmful photosensitizers, on wound healing and reactive oxygen species (ROS) production induced by photodynamic reactions. We found that irradiation of MB with high-intensity red LED at controlled energy levels promoted cell proliferation, migration, and production of wound healing factors. Furthermore, ROS production by a photodynamic reaction enabled the translocation of phosphorylated Grb2-associated binder-1, activating Extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase signals. Our findings suggest that proper control of ROS production has a beneficial effect on gingival fibroblasts, which constitute periodontal tissue, from the perspective of gingival wound healing.doctoral thesi
ラットモデルにおいて加熱式タバコ煙成分は歯の移動速度遅延を誘発する
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Purpose: This study aimed to evaluate the effect of the components of tobacco smoke from heated tobacco products (HTPs), referred to as Tobacco Smoke Components (TSCs), on tooth movement and the number of osteoclasts in rat models.
Materials and Methods: Wistar rats were divided into the following groups: control, distilled water-administered, cigarette TSCs-administered, and HTP TSCs-administered. Tooth movement was experimentally induced within each group using the Waldo method. Measurements were performed for tooth movement and the number of osteoclasts.
Results: Both cigarette and HTP TSCs decreased the number of osteoclasts and delayed the rate of tooth movement. The TSCs of cigarettes were particularly shown to have a stronger effect than the HTPs.
Conclusion: HTP TSCs significantly affected the rate of tooth movement; thus, orthodontists should be aware of the patient's smoking status, as well as smoking method (paper or heated), and encourage smoking cessation during treatment.doctoral thesi
下顎骨骨欠損モデルにおけるコラーゲンモデルポリペプチド/αリン酸三カルシウムスポンジによる骨形成
Get PDF大阪歯科大学Osaka Dental University博士（歯学）We investigated the effect of synthesized collagen model polypeptides consisting of a proline-hydroxyproline-glycine (poly(PHG)) sequence combined with porous alpha-tricalcium phosphate (α-TCP) particles on bone formation in a mandibular canine defect model. The porous α-TCP particles were mixed with a poly(PHG) solution, and the obtained sponge was then cross-linked and analyzed by scanning electron microscopy. The optimal mixing concentration of α-TCP granules and the poly(PHG) solution was decided to be 0.15g/mL by compression testing. The osteoblastic differentiation with the ALP activity of human mesenchymal stromal cells (hMSCs) cultured on the poly(PHG)/α-TCP was slightly greater than that of hMSCs cultured on the poly(PHG). Mandibular defects were analyzed in healthy beagles using micro-computed tomography and histological evaluation. At 2 and 4 weeks, the volume density of new bone was grater in the poly(PHG)/α-TCP group than in the group with only poly(PHG) (p 0.05). Histological evaluation at 4 weeks after implantation revealed that the poly(PHG) had degraded and that newly formed bone was present on the surface of the α-TCP particles. This study demonstrates that the composite created using porous α-TCP particles and poly(PHG) is sufficiently adaptable for treating the mandibular defect model.doctoral thesi
顎運動モーションキャプチャによる咀嚼運動パターンが、咀嚼能力に及ぼす影響について
Get PDF大阪歯科大学Osaka Dental University博士（歯学）The present study attempted to classify masticatory movements into two types, the grinding and chopping based on items evaluated in a motion capture analysis of jaw movements. We also examined the effects of each movement pattern on masticatory performance (MP). Nineteen healthy adults were selected from the database of our previous study. They were photographed with a high‐speed camera while chewing a gummy jelly. The amount of glucose extracted (AGE) from the gummy jelly was measured as a reference value for MP. Subjects were divided into two groups according to masticatory movement patterns. The grinding type was defined as a transition phase rate (TR) >35% and horizontal distance (HD) >6.0 mm, and the chopping type as TR <35% and HD <6.0 mm. No significant differences were observed in age, percentage of males, BMI, or the number of teeth between the groups. AGE was significantly higher in the grinding type group than in the chopping type group (154.6±45.3 mg/dL vs 202.0±41.0 mg/dL, p<0.028). Masticatory movement patterns were classified by a motion capture analysis of jaw movements. A relationship was observed between masticatory movement patterns and MP measured with the gummy jelly. Therefore, MP may be evaluated using a motion capture analysis.doctoral thesi