Osaka Dental University Academic Repository / 大阪歯科大学学術リポジトリ
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インプラント周囲炎における老化細胞の同定とセノリティクスによるミニインプラント脱落の防止
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Peri-implantitis is a disease that causes the detachment of orthodontic mini-implants.
Recently, stress-induced senescent cells have been reported to be involved in various inflammatory diseases. Senescent cell-eliminating drugs, termed “senolytics”, can improve the symptoms of such diseases. However, the relationship between peri-implantitis and senescent cells remains unclear. In this study, we evaluated the presence of senescent cells in a rat peri-implantitis model developed with a gum ring. The effect on bone resorption and implant loss was also investigated with and without senolytics (Dasatinib and Quercetin). The number of senescence markers (p19, p21, and p16) was found to increase, and implant detachment occurred in 24 days. After the administration of senolytics, the number of senescence markers decreased and implant detachment was inhibited. This study suggests that senescent cells aggravate peri-implantitis and senolytic administration latently reduces implant loss by inhibiting senescence-related mechanisms.doctoral thesi
青色LEDのう蝕原性細菌Streptococcus mutansと歯肉上皮細胞に及ぼす影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）We investigated the effect of blue light-emitting diode (LED) irradiation on the cariogenic bacteria Streptococcus mutans (S. mutans) and gingival epithelial cell line GE-1 cells. Light-emitting diodes with a wavelength of 465 ± 10 nm were used to irradiate S. mutans and GE-1 cells, and the cell viability was measured. The induction of the antioxidant enzyme heme oxygenase-1 was evaluated using quantitative reverse transcription polymerase chain reaction and western blotting. The results showed that blue LED irradiation with vitamin B partly suppressed the growth of S. mutans, and induced reactive oxygen species in GE-1 cells, thereby reducing cell viability.doctoral thesi
様々な口腔状態がQOLに与える影響の評価
Get PDF大阪歯科大学Osaka Dental University博士（歯学）We calculated the utility scores for various oral conditions using the time tradeoff (TTO) method which is an indextype scale. A nationwide survey was conducted in Japan among the general population using the internet. The utility score was calculated for each participant using the TTO method for 17 hypothetical oral conditions presented on a computer according to five assumed tooth loss conditions and medical interventions for each. When we analyzed the survey responses obtained from 2193 individuals, we found that the utility score declined as the number of missing teeth increased for the different tooth loss conditions. Furthermore, a histogram of the data representing the utility score exhibited a bimodal pattern for all oral conditions, and the bimodal data shifted with medical intervention, showing an increase in the utility score. These results enabled the calculation of utility scores for oral conditions in Japanese individuals and demonstrated that tooth loss affected the utility score.doctoral thesi
ブラジル連邦共和国バイーア州産プロポリスの口腔細菌への影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Oral care from a young age is important for the prevention of dental caries and periodontal disease, as well as systemic diseases. Propolis, which has been used in traditional medicine for centuries, has value as a new oral care product because of its low toxicity, low allergenicity, and antimicrobial activity. However, the chemical composition of propolis extracts are extremely complex and influenced by region in the area where honey been live. In order to use propolis in oral care products, it is necessary to find out what ingredients it contains and how active they are. In this study, we evaluated the antimicrobial activity of a new Bahia propolis against oral pathogens. The results showed that the product has antimicrobial activity against the periodontopathogenic bacteria Porphyromonas gingivalis (P. gingivalis) and early colonizer Actinomyces oris. In particular, the effect on P. gingivalis was comparable to that of antimicrobials and disinfectants. Our results showed that the new Bahia propolis is a promising antimicrobial agent that may prevent oral infections.doctoral thesi
PEEK材を用いて開発された歯科用根管拡大装置がスミア層除去に及ぼす影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Reaming and filing are used fot pulp extraction and cleaning infected root canals. The smear layer is a residue of softened dentin in the dentin tubules. In endodontic treatment, the removal of the smear layer is very important in terms of infection control. Poly Ether Ether Ketone (PEEK) material has excellent resistance to heat, hydrolysis, chemical breakdown, radiation, and flames. It is widely used in industry for cleaning automobile parts such as gears. This study used PEEK material, which was developed as a root canal expander. A scanning electron microscope was used to evaluate its effect on the removal of the smear layer in the root canal.doctoral thesi
3軸加速度センサを応用した下顎活動量の測定の信頼性ならびに解釈可能性に関する研究
Get PDF大阪歯科大学Osaka Dental University博士（口腔科学）The purpose of this study was to examine the reliability and interpretability of mandibular activity obtained from two different signal processing methods employing a three-axis accelerometer during mastication of mastication initiation training foods using the generalizability theory. The subjects were 17 healthy dentulous individuals with a mean age of 23.2±1.3 years who had no problems with mastication or swallowing. We calculated two types of mandibular activity, namely the mandibular activity (MA) detected from the central region of the chin and corrected mandibular activity that corrected MA using the activity of the forehead. For each subject, there were two measurement days at 1-week intervals, and three repeated measurements. To examine reliability, a generalizability study (two-facet crossed design) was performed with the subjects being the object of measurement, and the date of measurement and the number of measurements as the two facets. We found that when measuring mandibular activity, the use of mandibular activity corrected for forehead motion (head sway) and the use of the mean measurement over multiple days improved reliability and interpretability.doctoral thesi
γ-D-グルタミル-メソ-ジアミノピメリン酸（iE-DAP）は、ヒト歯髄線維芽細胞様細胞におけるマトリックスメタロプロテイナーゼ-1産生を調節する
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Nucleotide-binding oligomerization domain 1, which is constitutively expressed in human dental pulp fibroblast-like cells (hDPFs), plays a role in pulpal immune responses by sensing γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) from bacteria. Matrix metalloproteinase-1 (MMP-1) is an important enzyme that degrades type I collagen, an extracellular matrix component, and is involved in the destruction of dental pulp tissue. In the present study, we investigated the involvement of the ERK1/2 signaling pathway in MMP-1 production by iE-DAP-stimulated hDPFs. iE-DAP was not cytotoxic against hDPFs and did not affect their proliferation. A stimulation with iE-DAP enhanced MMP-1 production and ERK1/2 phosphorylation. The ERK1/2 signaling pathway was involved in the production of MMP-1 by iE-DAP-stimulated hDPFs. These results suggest that the induction of MMP-1 production by iE-DAP-stimulated hDPFs exacerbates pulpitis by promoting the degradation of surrounding collagen.doctoral thesi
女性の笑顔における歯冠色の違いが男性および女性の歯学部学生の印象に及ぼす影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）In recent years, there has been a tremendous increase in interest in dental esthetics. In prosthodontic clinical practice, patients are highly concerned with tooth color, among other esthetic requirements, and they have a strong desire to have white teeth. However, it is not clear what impression a person’s tooth color gives to others, nor is it clear whether there is a difference between the impression men and women have. The purpose of this study was to determine the influence of different teeth colors have on the impression female smiles give by using the semantic differential method and factor analysis. The subjects were 52 students undergoing clinical training at the School of Dentistry, Osaka Dental University. The average face of 10 adult women whose tooth color had been converted by image processing to C4, A2 or NW0 according to the shade guide was used as the stimulus image, and an impression measurement was performed. As part of the statistical analysis, an exploratory factor analysis was conducted on the impression structure of different tooth colors on the impression of female smiles. The extracted factors were subjected to two-way analysis of variance (mixed design), with tooth color and gender as factors. In the factor analysis, two factors were extracted: “gorgeous” and “natural.” The analysis of variance revealed a difference in the main effect of tooth color for both factors. These findings suggest that differences in tooth color have an influence on the impression female smiles give to dental students, irrespective of their gender.doctoral thesi
脱タンパクウシ骨ミネラルを用いた上顎洞底挙上術における術後洞粘膜穿孔の発現:ウサギを用いた組織学的評価
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Purpose: To examine the reaction of mucosa over time to a close contact with biomaterial after sinus elevation performed with deproteinized bovine bone mineral (DBBM) granules of two different sizes.
Materials and methods: Bilateral sinus mucosa elevation was performed in 18 New Zealand rabbits through access on the nasal dorsum. DBBM with granule dimensions of either 1 to 2 mm (large group) or 0.250 to 1.0 mm (small group) were used to randomly fill the subantral hollow spaces. Biopsy specimens of the experimental sites from six animals in each group were obtained 2, 4, and 8 weeks after the surgery.
Results: The integrity of the sinus mucosa was clinically evaluated during surgery using a ×2.5 magnifying visual device. The sinus mucosa in contact with the biomaterial granules was found to be thinned compared with the pristine mucosa in all periods examined. Three hundred fifty-two thinned zones were found considering all 36 sinuses treated. Perforations of the sinus mucosa with extrusion of granules toward the sinus were observed, increasing in number over time. In the 8-week healing period, five perforations in three sinuses and eight perforations in four sinuses were found in the large and small groups, respectively. No differences were seen between the large and small groups. The differences between 2 and 8 weeks were statistically significant for the thinned mucosa width in both the large and the small groups and for the number of sinuses and perforations for the small group.
Conclusion: Thinning zones and perforations of the sinus mucosa were seen increasing in number over time in regions in contact with graft granules in both the large and small groups.doctoral thesi
xCT阻害によるフェロトーシスは上皮間葉転換状態の口腔扁平上皮癌細胞に効果的に誘導される
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Ferroptosis is a newly discovered form of cell death that exhibits effective tumor suppression in various cancer cell types. Since ferroptosis efficiently decreases the viability of cancer cells undergoing epithelial-mesenchymal transition (EMT), it may exert anti-tumor effects on highly malignant oral squamous cell carcinoma (OSCC) in EMT. xCT is a subunit of a the cystine-glutamate antiporter. Ferroptosis occurs due to increased oxidative stress by inhibiting xCT. We induced EMT in OSCC cells and examined the effects of the induction of ferroptosis by inhibiting xCT in these cells. We investigated whether xCT inhibitor erastin induced ferroptosis in OSCC cells in vitro. Furthermore, we induced the EMT state in OSCC cells by the administration of transforming growth factor-β1 and examined the sensitivity of OSCC cells to ferroptosis in the presence or absence of the EMT state. Erastin induced ferroptosis in the OSCC cells. Ferroptosis-induced reductions in cell viability were greater in OSCCs of the mesenchymal state by EMT than in those in the normal state. OSCC cells in the mesenchymal state induced by EMT were highly susceptible to ferroptosis. The mesenchymal properties induced by EMT increase the malignancy of cancer cells. Therefore, therapy involving the induction of ferroptosis has potential in the treatment of advanced OSCC with invasion and metastasis.doctoral thesi