Osaka Dental University Academic Repository / 大阪歯科大学学術リポジトリ
Not a member yet
211 research outputs found
Sort by
咀嚼運動の制限が嚥下機能に及ぼす影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Background: Swallowing is a semi-automatic muscular action that plays a critical role in our daily food intake routine. Dysphagia, caused by diseases, accidents, or aging, can be a major contributor to a reduced quality of life. Often, only symptomatic therapy options exist for dysphagia. Therefore, to develop improved treatment and prevention methods, a better understanding of the pathophysiology associated with dysphagia is needed.
Objective: This study aimed to investigate the intercorrelation between mastication and swallowing, specifically focusing on the effect of restricted mastication duration on swallowing function.
Methods: Thirty healthy men (25±3 years old, mean±SD) were instructed to masticate a gummy jelly for free mastication (G100), half, and one-quarter duration of G100. Masseter and digastric electromyograms (EMGs) were recorded as parameters, representing masticating and swallowing, respectively, along with the velocity of the thyroid cartilage ridge measured with an accelerometer. Masticatory efficiency was evaluated using a glucosensor. The root mean square (RMS) of muscle EMG activity, the number of masticatory cycles, time to peak and total duration of each masticatory cycle, swallowing duration and latency, and masticatory efficiency were analyzed.
Results: Restricting mastication duration reduced the number of mastication cycles and prolonged the time to peak and total duration of masticatory cycles, which increased masticatory muscle activity. On the other hand, shortened duration and latency of swallowing increased swallowing muscle activity. Consequently, masticatory efficiency decreased.
Conclusion: Under restricted mastication conditions, habitual masticatory patterns could be optimized to achieve safe swallowing in healthy individuals.doctoral thesi
隣接する歯の条件やシェードタブの組み合わせが測色歯に与える影響
Get PDF大阪歯科大学Osaka Dental University博士（口腔科学）We investigated the effect of the condition of adjacent teeth and combinations of shade tabs on the colorimetry of maxillary central incisors. For natural teeth, we considered two conditions: one with a masking device to conceal adjacent teeth and the other without masking. For shade tabs, we assessed two conditions: one with only one A2 shade tab and another with three A2 shade tabs. In addition, we explored various color combinations of the three shade tabs. Photographs were recorded using a digital camera in a dark room with no ambient light to ensure consistent conditions. The condition with the masked natural teeth and that with only one shade tab exhibited reduced levels of lightness and chroma, with a noticeable yellowish hue. No significant differences were noted in visual coloration among the different shade tab combinations. However, significant differences were noted in lightness, chroma, and hue angle. These results emphasize the importance of arranging shade tabs correctly when determining and recording the color of natural teeth, particularly when making visual shade comparisons.doctoral thesi
D-プシコースのCandida albicansの増殖および菌糸発現への影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）D-Psicose (C6H12O6), also referred to as D-allulose, is a well-known rare sugar that exists as a monosaccharide in nature and has approximately 70% of the sweetness of sucrose and no calories. In recent years, D-psicose has been reported to have a variety of physiological effects in animals and humans, such as anti-inflammatory and antioxidant effects. In this study, we investigated the effect of D-psicose on the growth of Candida albicans (Ca) - a heterotrophic fungus that is commonly found in humans and which is a frequent etiological agent of candidiasis. We observed morphological changes using two microscopic techniques. Furthermore, we analyzed the expression of virulence-related genes in Ca when cultured in liquid medium containing 4% D-psicose at 37°C under aerobic conditions using quantitative reverse transcription-PCR (qRT-PCR) methods. Compared to culturing in liquid Sabouraud’s medium containing 4% D-glucose (SM), Ca took longer to reach the stationary growth phase in liquid peptone medium containing 4% D-psicose (PM). Further, in the methyl thiazolyl tetrazorium (MTT; 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay, Ca strain ATCC 10261 cultured in liquid PM showed a significant reduction in metabolic activity (approximately 80%) when compared culturing in liquid SM, suggesting that D-psicose reduces Ca viability. Interestingly, microscopic analysis revealed the inhibition of hyphal development in Ca cultured in liquid PM at 37°C. In addition, qRT-PCR showed downregulation of the expression of virulence-related genes HWP1 and PLB1 in Ca cultured in liquid PM compared to Ca cultured in liquid SM. Taken together, these results show that D-psicose weakens the growth and inhibits hyphal development of Ca, and strongly suggest that D-psicose suppresses Ca morphogenesis and biofilm formation. By substituting sugar (glucose) with D-psicose in the daily diet, it may be possible to delay the onset of candidiasis in the body and oral cavity of the aged and immunocompromised patients, and thus, to reduce the frequency of dental visits for maintaining the oral cavity and dental prosthesis. This is the first report regarding the impact of D-psicose, a rare sugar, on Ca.doctoral thesi
Lipopolysaccharide徐放性ゼラチンの性質に及ぼすLPS濃度と脱水熱処理回数の影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Lipopolysaccharide (LPS) is a potential inducer of chronic inflammation, cellular senescence, and impaired bone regeneration. LPS sustained-release gelatin (LS-G), developed in our previous studies, is a useful chronic inflammation-inducing device; the application of LS-G has the potential to freely induce and regulate inflammation and cellular senescence in animal models via the sustained release of LPS and may be useful in elucidating pathological mechanisms. However, there is a paucity of information on the effects of conditions such as LPS concentration and the number of dehydrothermal treatments (DHT) on LS-G. Here, we investigated the effect of adjusting the number of DHT (1vh, 2vh) and concentration of LPS (×1, ×6, ×10, ×100) on the LS-G properties. First, we showed that implantation of LS-G with high LPS concentration can induce chronic inflammation in vivo. Next, we compared the LS-Gs under each condition for the properties, such as the microstructure, water absorption time, and the LPS release behavior. The microstructure of the LS-G surface showed a few changes depending on the concentration of LPS or the number of DHT. The water absorption time significantly increased with the number of DHT. The LPS concentration was found to be related to the release of LPS. These results suggest that regulation of the number of DHT and the concentration of LPS may be useful for modulating the properties of LS-G. This study may lead to the development of highly functionalized LS-G that contribute to the development of an efficient model of chronic inflammation, cellular senescence, and impaired bone regeneration.doctoral thesi
骨格性開咬の側貌軟組織形態の評価
Get PDF大阪歯科大学Osaka Dental University博士（歯学）We investigated the characteristics of the hard tissue morphology and lateral soft tissue profile of adult patients with skeletal open bite in order to examine the possibility of predicting soft tissue morphological changes after orthodontic treatment. We measured the hard tissue characteristics of 80 adult females diagnosed with skeletal open bite using lateral cephalograms at the time of initial examination, for Steiner analysis, FMA, IMPA, and Gonial angle. Next, the soft tissue was measured for Dentoskeletal factor, Soft tissue structure, Facial length, Projection TVL, and Facial harmony by Arnett analysis using lateral cephalograms obtained at the time of the initial examination. The correlation between hard and soft tissues was examined based on the obtained measurements. We found a correlation between the hard and soft tissues of the midface and lower face. These results suggest that it is possible to predict changes in soft tissue morphology due to changes in hard tissue morphology resulting from orthodontic treatment.doctoral thesi
ゼラチンハイドロゲルを結合した生体活性ポリエーテルエーテルケトンは骨形成因子の徐放と骨分化促進をもたらす
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Polyetheretherketone (PEEK) is one of the most promising implant materials for hard tissues due to its similar elastic modulus; however, usage of PEEK is still limited owing to its biological inertness and low osteoconductivity. The objective of the study was to provide PEEK with the ability to sustain the release of growth factors and the osteogenic differentiation of stem cells. The PEEK surface was sandblasted and modified with polydopamine (PDA). Moreover, successful sandblasting and PDA modification of the PEEK surface was confirmed through physicochemical characterization.
The gelatin hydrogel was then chemically bound to the PEEK by adding a solution of glutaraldehyde and gelatin to the surface of the PDA-modified PEEK. The binding and degradation of the gelatin hydrogel with PEEK (GPEEK) were confirmed, and the GPEEK mineralization was observed in simulated body fluid. Sustained release of bone morphogenetic protein (BMP)-2 was observed in GPEEK. When cultured on GPEEK with BMP-2, human mesenchymal stem cells (hMSCs) exhibited osteogenic differentiation. We conclude that PEEK with a gelatin hydrogel incorporating BMP-2 is a promising substrate for bone tissue engineering.doctoral thesi
歯科衛生士養成課程に在学する学生の臨床実践能力と 自己教育力に関する意識調査
Get PDF大阪歯科大学Osaka Dental University博士（口腔科学）近年，歯科衛生士が社会から求められるニーズは多様化しており，歯科衛生士養成課程についても対応が求められている．歯科衛生士がそうした変化に対応できるよう，養成課程において自己教育力を養うことが重要である．看護学分野では臨地実習が自己教育力を伸ばす機会の一つであるとの検討が多くなされているが，歯科衛生士養成課程における臨地実習と自己教育力育成との関連についてはほとんど検討されていない．本研究では，3年制の専門学校と短期大学，そして4年制大学それぞれの歯科衛生士養成課程に学ぶ学生を対象に，臨床実習前後で，臨床実践能力や自己教育力に関する自己評価方式の意識調査（臨床実践能力習得状況：24問，臨床実習に対する思いや考え：6問，自己教育力：40問）を行い，臨床実習が臨床実践能力や自己教育力に与える影響や，学校群別の違いについて検討した．実習前は計401名，実習後は計340名の学生から本調査への協力が得られ，回答を学校群別に集計し，実習前／後という時間と，学校の違いの2つの要因で二元配置分散分析を行った．結果として，臨床実習の経験により，すべての学校群の学生が自らの臨床実践能力の向上について肯定的意識を持っていることが分かった．学校群別では，専門学校や短期大学の学生は実習前から比較的高い自己評価をしている一方で，4年制大学の学生は比較的低かった自己評価を最も大きく伸ばす傾向があった．自己教育力については，4年制大学の学生は有意に伸ばす面がいくつかあったものの，専門学校や短期大学の学生にはそうした効果は現れなかった．臨床実践能力の向上と自己教育力の向上は必ずしも結び付かないことや，養成期間や養成校の違いによっても自己教育力の向上への効果に相違が見られたことは，今後の歯科衛生士養成課程における教育方法の改善を図る上で，学校群別の調整が必要であることを示唆しており，重要な結果である．doctoral thesi
ヒト歯肉上皮細胞のInterleukin-8産生に対するtumor necrosis factor -αの影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Tumor necrosis factor (TNF)-α is an inflammatory mediator that is released during the early stages of the inflammatory response and plays an important role in the development of periodontitis. Interleukin-8 (IL-8) is associated with the attraction and activation of neutrophils into the area of inflammation, which is considered an important factor in the regulation of inflammatory responses. In this study, we investigated the effect of TNF-α stimulation on IL-8 production in Ca9-22 cells, a human gingival epithelial cell line. Stimulation with TNF-α enhanced IL-8 production and ERK1/2 phosphorylation. U0126, a potent and selective MEK1/2 inhibitor, inhibited phosphorylation of ERK1/2 but not p38. These findings suggest that the enhancement of IL-8 production by TNF-α-stimulated Ca9-22 may lead to the induction and activation of neutrophils into inflamed tissues and worsen periodontitis.doctoral thesi
3Dスキャナーを利用した補綴装置の適合性の改善
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Purpose: We superimposed the digital scan data of a maxillary complete denture fabricated by microwave curing with the digital scan data of a physical working model, then investigated the change in fit by adjusting interference areas.
Methods: The scan data of 10 maxillary complete dentures fabricated by microwave curing and 10 working models were superimposed to investigate changes in fit according to adjustment of interference areas. The interference areas were then machined and reevaluated.
Main results: The fit rates were 60.1±4.8% immediately after polymerization, 69.3±5.9%for the first round of grinding, and 73.4±6.0% for the second round of grinding. Oneway analysis of variance showed that the compliance rate significantly increased with grinding. Additionally, multiple comparisons were made between uncut and first grinding, first and second grinding, and uncut and second grinding; the fit rate significantly increased in all cases. Repeated measurements and analysis of variance regarding deviation between the working model and the finished denture showed that the deviation was significantly reduced by grinding and the overall fit was improved; however, there were differences among the sites, and not all sites displayed similar improvement.
Principal conclusions: By superimposing the stereolithography data of a working model on the mucosal surface of a maxillary complete denture using a threedimensional scanner, we were able to improve the fit.doctoral thesi
歯周炎の発症におけるヌクレオチド結合性多量体ドメイン1経路の役割
Get PDF大阪歯科大学Osaka Dental University博士（歯学）During innate immune defense, host pattern recognition receptors, including toll-like receptors and nucleotide-binding oligomerization domain-like receptors (NLRs), can activate downstream pathways by recognizing pathogen-associated molecular patterns produced by microorganisms, triggering immune responses. NOD1, an important cell membrane protein in the NLR-like receptor protein family, exerts anti-infective effects through γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) recognition. Oral epithelial cells resist bacterial invasion through iE-DAP-induced interleukin (IL)-8 production, recruiting neutrophils to sites of inflammation in response to bacterial threats to periodontal tissues. To date, the regulatory mechanisms of iE-DAP in gingival epithelial cells (GECs) are poorly understood. This study was conducted to investigate the role of the NOD1 pathway in the development of periodontitis by examining the effect of iE-DAP on IL-8 production in Ca9-22 cells.IL-8 production by iE-DAP-stimulated-Ca9-22 cells was assessed using an enzyme-linked immunosorbent assay. Phosphorylation levels of intracellular signaling molecules were evaluated using western blot analyses. iE-DAP induced NOD1 receptor expression in Ca9-22 cells. Additionally, iE-DAP induced expression of pro-IL-1β protein without extracellular secretion. Our results suggest that iE-DAP regulates IL-8 production by activating p38 mitogen-activated protein kinase (MAPK) and ERK1/2 signaling pathways. iE-DAP also promoted nuclear factor kappa-B p65 phosphorylation, facilitating its nuclear translocation. Notably, p38 MAPK and ERK1/2 inhibitors suppressed iE-DAP-stimulated IL-8 production, suggesting that JNK is not involved in this mechanism.Our results indicate that p38 MAPK and ERK1/2, but not JNK, are involved in innate immune responses in GECs.doctoral thesi