Osaka Dental University Academic Repository / 大阪歯科大学学術リポジトリ
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フソバクテリウム・ペリオドンティクムに対する5-アミノレブリン酸媒介光力学療法の殺菌効果
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Periodontitis is a chronic infectious disease that causes gingival atrophy and tooth loss via alveolar bone resorption. Fusobacterium periodonticum is a key species involved in chronic periodontitis. Controlling the abundance of F. periodonticum is vital for the prevention and treatment of periodontal diseases. Photodynamic therapy (PDT) combined with 5-aminolevulinic acid (5-ALA) exerts bactericidal effects against Pseudomonas aeruginosa and Staphylococcus aureus. Here, we investigated the bactericidal potential of 5-ALA combined with PDT (ALA-PDT) against F. periodonticum. We used F. periodonticum JCM12991 and a 410-nm light-emitting diode in this study. First, we evaluated the bactericidal effect of ALA-PDT on F. periodonticum, and then explored its underlying mechanisms by analyzing its fluorescence, enzymatic activity, and membrane integrity. Culturing with 0.5% 5-ALA for 20 h confirmed a significant bactericidal effect of ALA-PDT against F. periodonticum. Fluorescence analysis revealed that F. periodonticum produced excitable photosensitive substances after the addition of 5-ALA. Furthermore, cell membrane disruption was observed in F. periodonticum following ALA-PDT. We found that ALA-PDT exerted antibacterial activity against F. periodonticum. If further studies confirm these results, this protocol could be an effective strategy for reducing the prevalence of periodontitis.doctoral thesi
次世代シークエンサーを用いた慢性歯周炎細菌叢の経時解析
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Chronic periodontitis is a multifactorial disease that is strongly impacted by the oral microflora. Althought changes in the oral flora are related to the induction of gingival inflamation and alveolar bone resorption, there changes have not been extensively evaluated over time in patients with chronic periodontitis. Therefore, we analyzed the changes in the chronic periodontitis bacterial flora over time using next-generation sequencing. Subgingival plaque and saliva samples were collected from four patients diagnosed withchronic peridontitis at the time of the initial examination and at the end of basic periodontal treatment. The 16S rRNA gene region was amplified using PCR with DNA extracted from the samples as a template and sequenced using a next-generation sequencer. Bacterial flora were identified using QIIME2. Bacteria in the genera Streptococcus, Porphyromonas, Fusobacterium, Veillonella, Neisseria, Prevotella, Tannerella, and Corynebacterium were detected in 16 samples isolated from four participants. Alpha and beta diversity significantly differd between the four participants in the plaque and saliva flora, with no significant changes observed before and after treatment. A declining trend in Porphyromonas gingivalis and Fusobacterium nucleatum was observed exclusively in samples exhibiting a clinical response to the treatment.doctoral thesi
脳梗塞後段階的再灌流が再灌流障害におよぼす影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）The present study aims to investigate the effect of mechanically avoiding hyperperfusion on reperfusion injury. Experiments were performed using a CB17-strain mouse cerebral ischemia model with excellent reproducibility of infarct foci. After occlusion of the left middle cerebral artery for 45 minutes under sevoflurane anesthesia, the experimental group was divided into two groups as follows: "full opening immediately after occlusion (Total reperfusion group)" and "full opening after 30 minutes of half opening (stepwise reperfusion group). In each group, brain sections were frozen after reflux fixation on the next day and after 2 and 3 days. Pericytes, neurons, glial cells, neural stem cell markers, and apoptosis markers were evaluated using immunohistochemistry staining. Three days later, we performed triphenyl tetrazolium chloride staining to check the expression of cerebral infarcts. We found no difference in the occurrence of cerebral infarction and neuronal loss in the cerebral cortex; however, in the total reperfusion group, pericyte damage and loss were more frequent in the area from the cerebral cortex to the striatum. Therefore, if blood flow after cerebral infarction of unknown onset can be restored gradually to reduce hyperperfusion immediately after recanalization, reperfusion injury can be reduced, and this may be beneficial for nerve regeneration.doctoral thesi
ゼノフリー環境下におけるラット脂肪由来幹細胞の骨形成能の評価
Get PDF大阪歯科大学Osaka Dental University博士（歯学）This study aimed to develop a novel culture method for rat adipose-derived stem cells(rADSC) and evaluate their osteogenic potential. The rADSC cultured in xeno-free culture medium
(XF-rADSCs) or conventional culture medium containing fetal bovine serum (FBS-rADSCs) were com bined with micropieces of xeno-free recombinant collagen peptide to form 3-dimensional aggregates(XF-rADSC-CellSaic or FBS-rADSC-CellSaic). Both FBS-rADSC and XF-ADSC in CellSaic exhibited multilineage differentiation potential. Compared to FBS-rADSC-CellSaic, XF-rADSC-CellSaic ac celerated and promoted osteogenic differentiation in vitro. When transplanted into rat mandibular
congenital bone defects, the osteogenically differentiated XF-rADSC-CellSaic induced regeneration of bone tissue with a highly maturated structure compared to FBS-rADSC-CellSaic. In conclusion, XF-rADSC-CellSaic is a feasible 3-dimensional platform for efficient bone formation.doctoral thesi
電気刺激強度による睡眠時ブラキシズムの軽減効果
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Background: Although biofeedback with contingent electrical stimulation (CES) has demonstrated the reduction effect on sleep bruxism (SB), the relationship between the actual applied CES intensity and efficacy remains uncertain.
Objective: This study aimed to investigate whether the reduction of bruxism events and jaw muscle symptoms could vary according to the intensity of CES and in prob-able sleep bruxers.
Methods: Twenty probable sleep bruxers were initially screened for bruxer confirma-tion based on a 2- week recording of SB events with a portable electromyography recorder (BUTLER®GrindCare®, GC4). A 3- week recording was conducted without CES using a GC4, followed by another 3- week recording with CES. At baseline and before and after the CES (+) session, clinical muscle symptoms were assessed using a 0–10 numerical rating scale (NRS). The relationships between the actual applied CES intensity and the number of SB events/hour, as well as the NRS of clinical muscle symptoms, were analysed.
Results: The actual applied CES intensity was positively correlated with the reduction rate of the number of SB events/hour (R = .643, p = .002), as well as with the reduction rate of NRS for pain, unpleasantness, fatigue, tension and stiffness (R > .500, p < .011).
Conclusion: Higher CES elicited a more robust reduction in SB events and clinical muscle symptoms, in probable bruxers. Prior to selecting CES biofeedback as a man-agement option for SB, it would be beneficial to assess the tolerance threshold of CES in each bruxer in order to predict the effectiveness of CES in probable sleep bruxers.doctoral thesi
表面改質がPolyetheretherketone表面におけるヒト歯肉上皮細胞の挙動に及ぼす影響
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Gingival epithelial attachment to the abutment is important for the prevention of peri-implantitis. Polyetheretherketone (PEEK) has recently gained attention as an alternative material to titanium. Ultraviolet (UV) irradiation, argon plasma irradiation, and buffing were selected as treatments to reduce the carbon elements inhibiting cell behavior. None of the treatments had any effect on the material’s mechanical strength. The UV and plasma treatments did not affect the surface morphology. Surface elemental analysis showed a decrease in carbon content and an increase in oxygen content and wettability for all treatments. Human gingival epithelial cell adhesion, proliferation, and the expression of adhesion proteins, were increased. The removal of carbon from the PEEK surface has been suggested to improve the cellular activity of PEEK.doctoral thesi
歯槽骨骨密度を用いた薬剤関連顎骨壊死のリスク評価
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Objectives: Osteosclerosis and a high bone mineral density (BMD) have been proposed as risk factors for medication-related osteonecrosis of the jaw (MRONJ). In the present study, we measured the alveolar BMD (al-BMD) of teeth indicated for extraction on dental radiographs using BMD analysis software and investigated the relationship between al-BMD and MRONJ.
Materials and Methods: We measured al-BMD on dental radiographs using BMD analysis software (Bone Right®) in 100 bone-modifying agent (BMA)-treated patients who visited our department for tooth extraction between November 2020 and May 2023. Fifteen patients treated with BMA for more than 4 years underwent tooth extraction 2 months after their cessation.
Results: In 100 patients who underwent tooth extraction, only one patient on high-dose anti-resorptive agents (ARAs) developed MRONJ. al-BMD was significantly higher in MRONJ patients than in non-MRONJ patients. No significant change was observed in al-BMD before and 2 months after the cessation of BMA.
Conclusion: Patients who developed MRONJ after tooth extraction had higher al-BMD before tooth extraction, and a relationship between MRONJ and osteosclerosis cannot be ruled out. On the other hand, al-BMD did not change before and after the cessation of BMA, and MRONJ did not occur in patients treated with low-dose ARAs, suggesting that the cessation of BMA is not necessary.doctoral thesi
ラット垂直的骨増生における炭酸アパタイトとβ-リン酸三カルシウムの比較：ポリテトラフルオロエチレンチューブを用いた生体吸収性骨補填材の比較検討
Get PDF大阪歯科大学Osaka Dental University博士（歯学）This study radiologically and histologically compared two bioresorbable bone substitutes with different compositions, carbonate apatite (Cytrans® Granules; CGs) and β-tricalcium phosphate (β-TCP), for vertical bone augmentation on a rat skull using a polytetrafluoroethylene (PTFE) tube. This PTFE tube was placed at the center of the skull, fixed with Super Bond, and augmented with CGs or β-TCP granules. Specimens with surrounding tissue were harvested at 4, 8, and 12 weeks postoperatively, and radiological and histological evaluations were performed. The bone volume to total volume ratio (BV/TV) of the β-TCP-implanted group was markedly higher than that of the CG-implanted group at 4 and 12 weeks postoperatively. Compared to CGs, β-TCP exhibited the ability to form blood vessels into the graft material for a short period after transplantation, as well as an elevated production of collagen into β-TCP granules during the bone formation process.doctoral thesi
鼻上顎複合体の成長発育による回転中心の転位に関する研究
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Purpose: This study aimed to detect the centre of spiral similarity (CS), an improvement of the centre of rotation when the jaw shows standard growth, and to evaluate and examine the dislocation of CS depending on the skeletal type, sex and age. Materials and Methods: This study included 107 patients aged 5–15 years (62 females and 45 males) examined at Osaka Dental University Hospital’s Department of Orthodontics for the primary complaint of malocclusion. For each patient, lateral cephalometric radiographs were taken before and after treatment. Skeletal types were classified into three groups (Class I, II and III) according to the McNamara analysis, and degrees of cervical vertebral maturation were classified into two groups (under 11 and 11 or over). We calculated CS using our previously reported method, derived the projective CS (pCS) to evaluate the dislocation of CS and compared pCS between skeletal groups. Results: The CS of Class I was located approximately 17–21 mm anterior and 4–8 mm inferior to the sella. Significant differences in pCS were found between Classes I and III. Furthermore, the sign of pCS showed an opposite trend depending on sex. Conclusion: The CS of ‘Class I and under 11’ is located near the spheno-ethmoidal synchondrosis, while that of ‘Class III and under 11’ was away from there in alternate directions for males and females. Our results provide insights into the trends that require different treatment strategies based on sex or other personal characteristics in orthodontics.doctoral thesi
放線菌MG-1はdTHP-1マクロファージ細胞において炎症反応を誘導する
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Actinomycetes, as one of the earliest colonizers in the oral environment, have been studied because previous research has found that they facilitate the colonization of other oral pathogens. Although the inflammatory responses triggered by Actinomycete in the oral cavity have not been considered very important, they may play a significant role in the progression of oral inflammatory diseases. We treated differentiated THP-1 cells (dTHP-1) transiently with Actinomyces oris (A. oris) MG-1 as an inflammatory model. We also used resveratrol, a naturally derived antiinflammatory compound, as an inflammatory inhibitor in our model. Using CCK8, ELISA, and western blotting to analyze the inflammatory model, we discovered that A. oris MG-1 reduced the viability of dTHP-1 cells. The secretion of IL-1β into the supernatant indicated an inflammatory response, which was further confirmed by the western blot results. We found that resveratrol has potential as an antiinflammatory intervention and is worthy of further investigation.doctoral thesi