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口腔外スキャンボディを使用した3次元仮想患者表現の精確さに関する in vitro 研究
Get PDF大阪歯科大学Osaka Dental University博士（歯学）In modern prosthodontic treatment, digital technology is rapidly gaining popularity in terms of facilitating treatment planning and the design and manufacture of prosthesis. Recently, technology to integrate three-dimensional data of facial structures and dentition has also been developed. We investigated the accuracy of two dental facial scan systems guided by an extraoral scan body currently available in Japan. The null hypothesis was that there was no difference in the accuracy of the three-dimensional virtual facial model between the two systems. The manikin head on which the maxillary arch model was mounted was scanned by a reference high precision laser scanner (FARO) and two dental face scanners, FACE HUNTER (FH) and FREEDOM F (FF). The scans from FH and FF were superimposed on the reference scan from FARO using the iterative closest point (ICP) method, and the mean deviation of the arch model was calculated. The accuracy (trueness and precision) was 0.403 ± 0.120 mm for the FH and 3.053 ± 0.568 mm for the FF, when compared with the FARO. The accuracy of the system was better in the FH than in the FF.doctoral thesi
頭位の違いが上顎前歯部の審美評価パラメータと笑顔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 esthetic dentistry, morphological harmony between the dentition and facial features is an important issue. It has been reported that the shape of the dentition and the impression of the maxillary anterior teeth, which are particularly important in esthetic dentistry, differ depending on the observer's viewing direction. This study utilized a 3D virtual patient generated by a dental face-scanning system as the experimental subject. Experiment 1 examined the reliability of the natural head position used to set the horizontal reference plane of the face in the system used in this study. Experiment 2 compared two esthetic evaluation parameters between three head positions – the head position with the Camper's plane as the horizontal reference plane (CP) and the head position with the Frankfort horizontal plane as the horizontal reference plane (FP) and the natural head position (NHP). Experiment 3, a questionnaire survey was conducted on dentists and dental technicians regarding their smile impressions in each head position. NHP obtained by the dental face-scanning system was shown to be highly reliable. Moreover, it was revealed that esthetic evaluation parameters and the impression of the smile differed according to the head position. It was suggested that the head position be set to FP or NHP when analyzing and evaluating the esthetics of the maxillary anterior teeth.doctoral thesi
有機無機複合材料の評価における実体顕微鏡の有用性
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Microscopy is a traditional method to estimate the morphology or microstructure of biomaterials. However, the use of stereomicroscopy with transmitted light for the analysis of organic-inorganic composite materials has not been widely explored. In this study, we aimed to verify the usefulness of stereomicroscopy with epi- and trans-illumination and field emission-scanning electron microscopy (FE-SEM) using the bone-substitute material, vacuum-heated epigallocatechin-conjugated gelatin sponges containing β-tricalcium phosphate granules, as model material. Compared with FE-SEM, in situ stereomicroscopy with trans-illumination facilitated the easy observation of the β-tricalcium phosphate granule distribution in sponges. Compared with epi-illumination, transmitted-illumination enabled easy detection of the fibrous structure of epigallocatechin-conjugated gelatin at the intergranular spaces and in the pores of β-tricalcium phosphate granules. Our findings suggest that the use of a stereomicroscope with trans-illumination may facilitate the scanning of the microstructure of organic-inorganic composite materials during biomaterial fabrication.doctoral thesi
Rothia dentocariosaに対するトランスポゾンの挿入
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Objectives
Rothia spp. are emerging as significant bacteria associated with oral health, with Rothia dentocariosa being one of the most prevalent species. However, there is a lack of studies examining these properties at the genetic level. This study aimed to establish a genetic modification platform for R. dentocariosa.
Methods
Rothia spp. were isolated from saliva samples collected from healthy volunteers. Subsequently, R. dentocariosa strains were identified through colony morphology, species-specific polymerase chain reaction (PCR), and 16S ribosomal RNA gene sequencing. The identified strains were then transformed with plasmid pJRD215, and the most efficient strain was selected. Transposon insertion mutagenesis was performed to investigate the possibility of genetic modifications.
Results
A strain demonstrating high transforming ability, designated as R. dentocariosa LX16, was identified. This strain underwent transposon insertion mutagenesis and was screened for 5-fluoroorotic acid-resistant transposants. The insertion sites were confirmed using arbitrary primed PCR, gene-specific PCR, and Sanger sequencing.
Conclusion
This study marks the first successful genetic modification of R. dentocariosa. Investigating R. dentocariosa at the genetic level can provide insights into its role within the oral microbiome.doctoral thesi
口腔領域の囊胞性疾患におけるアメロジェニンの発現
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Subcutaneous injection of enamel matrix derivative into rat back tissue results in the formation of eosinophilic round bodies (ERBs). When a large amount of ERBs are formed, they induce cartilage. Our previous studies have shown that ERB is a part of amelogenin exon-5. We therefore artificially created synthesised peptide (SP) with the same sequence as ERB. Subcutaneous injection of SP into rat back tissue induces bone and endochondral bone formation. Since amelogenin plays many important roles, we hypothesised that ERB, which is a part of amelogenin, may also play an important role. For this reason we produced a mouse monoclonal antibody (A-ERB) using SP, to investigate the function of ERB. In the present study, immunohistochemical staining with A-ERB was performed on oral cystic lesions in the expectation that A-ERB would react with odontogenic epithelium. We selected as test material seven human oral cystic lesions, the radicular cyst, dentigerous cyst, dermoid cyst, epidermoid cyst, orthokeratinised odontogenic cyst, odontogenic keratocyst, and unicystic ameloblastoma. They were sectioned and immunohistochemically stained using A-ERB. Although ERBs were expressed in the lining epithelium of dermoid cysts, they were not expressed in the epidermoid cysts. Although epidermis with cutaneous appendages expressed ERB, epidermis without cutaneous appendages did not. Dermoid and epidermoid cysts are now classified as the same lesion. However, the character of the lining epithelium of the two is different. Perhaps the two lesions should not be in the same category.doctoral thesi
インプラント応用のためのPLD法によるフッ素化ハイドロキシアパタイトを成膜したナノジルコニア材料の表面分析とオッセオインテグレーション評価
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Standard zirconia implants used in restoration still present problems related to inertness and long‐term stability. Various physicochemical approaches have been used to modify the implant surfaces to improve early and late bone‐to‐implant integration; however, no ideal surface modification has been reported. This study used pulsed laser deposition to deposit a fluorinated hydroxyapatite (FHA) film on a zirconia implant to create a biologically active surface. The film prepared was uniform, dense, and crack‐free, and exhibited granular surface droplets; it also presented excellent mechanical strength and favorable biological behavior. The FHA‐coated implant was implanted on the femur of Sprague–Dawley rats, and various tests and analyses were performed. Results show that the in vitro initial cell activity on the FHA‐coated samples was enhanced. In addition, higher alkaline phosphatase activity and cell mineralization were detected in cells cultured on the FHA‐coated groups. Further, the newly formed bone volume of the FHA‐coated group was higher than that of the bare micro‐adjusted composite nano‐zirconia (NANOZR) group. Therefore, the FHA film facilitated osseointegration and may improve the long‐term survival rates of dental implants, and could become part of a new treatment technology for implant surfaces, promoting further optimization of NANOZR implant materials.doctoral thesi
肥満２型糖尿病モデルラットにおける上顎第一臼歯口蓋側歯肉の上皮下結合組織と毛細血管の形態学的研究
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Although obesity is a lifestyle-related disease and a major risk factor for type 2 diabetes mellitus, the effects of obese type 2 diabetes mellitus (ODM) on oral health have not been fully elucidated. We compared the subepithelial connective tissue and capillary network of the palatal gingiva of the maxillary first molar in ODM model rats and normal rats. The subepithelial connective tissue of the two groups differed substantially. In particular, the cross-sectional area of the subepithelial connective tissue, the cross-sectional area and height of the connective tissue papillae, and the capillary diameter were significantly lower in the ODM rats compared with the normal animals (p < 0.01). In conclusion, hyperglycemia in ODM rats is associated with atrophic changes, evidenced by reduced cross-sectional area of the subepithelial connective tissue, as well as reduced cross-sectional area and height of the subepithelial connective tissue papillae. Furthermore, it causes diabetic microangiopathy in the capillary network of the palatal gingiva of the maxillary first molar in the ODM rats.doctoral thesi
膜内ロンボイドプロテアーゼ活性の解析
Get PDF大阪歯科大学Osaka Dental University博士（歯学）Rothia mucilaginosa is a part of the normal oral microflora, which has been recognized as an endodontic pathogen and is also an emerging opportunistic pathogen in immune compromised hosts. In this study, we identified the rhomboid protease in R. mucilaginosa as a candidate virulence factor. A database search identified two rhomboid genes on the genome with open reading frames of 828 bp and 822 bp, respectively. The two genes are separated by 57 bp, suggesting that they constitute a bicistronic operon. Motifs conserved among rhomboid family proteins (HxxxN, GxSG, and GxxxG) were found in their deduced amino acid sequences. The two recombinant rhomboids and the rhomboid/liposome complexes (proteoliposomes) were prepared using a wheatgerm cell-free translation system, and their serine protease activities were assessed. The two rhomboids showed serine protease activity in the form of rhomboid/liposome complex, while the recombinant rhomboids alone showed little or no activity. On the supposition of host invasion, R. mucilaginosa was cultivated in medium with type I collagen, and the rhomboid mRNA levels were examined. Real-time reverse transcription polymerase chain reaction analysis revealed that the levels of the two rhomboid mRNAs increased slightly in culture with type I collagen, although the changes were not statistically significant. These results suggested that R. mucilaginosa possesses two active rhomboids with protease activity on the membrane, and the two rhomboids may be virulence factors involved in the response to host environmental conditions.doctoral thesi
従来法の製作過程にデジタル歯科技術を取り入れて成型したマウスガードの適合性
Get PDF大阪歯科大学Osaka Dental University博士（歯学）The fit of mouthguards fabricated using working models produced by a 3D printer based on impressions taken with an intraoral scanner were compared with the fit of those fabricated by conventional methods, i.e. mouthguards formed on plaster models using a pressure thermoforming machine. A maxillary dentition model was used as the master model. A total of 20 working models were replicated with hard plaster. The master model was scanned using an intraoral scanner, and 10 working models were produced using a 3D printer. A pressure thermoforming machine was used for 10 of the working models, and a vacuum former was used for the other 10. Mouthguard sheets were formed on 10 plaster models and 10 3D printer models using a pressure thermoforming machine. Similarly, the mouthguard sheets were formed on 10 plaster models using a vacuum former. The fit of the mouthguards fabricated by thermoforming on the working model fabricated by the 3D printer was not comparable to that of those fabricated by the conventional method. However, it was better than that of the mouthguards fabricated using the vacuum former. We concluded that, the fit of the mouthguards fabricated by thermoforming on a working model fabricated by a 3D printer is clinically acceptable.doctoral thesi
サイナスオーグメンテーション後の骨形成にシュナイダー膜が与える影響： ウサギを用いた組織学的研究
Get PDFoai:osaka-dent.repo.nii.ac.jp:02000002大阪歯科大学Osaka Dental University博士（歯学）Aim: to evaluate bone formation in close contact with the sinus mucosa after different periods from sinus augmentation and the influence on healing of the presence of an inward dis-placed bone window. Material and Methods: Eighteen rabbits were included in the experiment. A trap-door technique was applied at the test sites, and the bony window was elevated inward (inward window;
IW) together with the sinus mucosa. At the control sites, the bony window was removed before the elevation of the sinus mucosa. The elevated space was filled with deproteinized bovine bone mineral (DBBM) and both access windows were covered with a collagen membrane. Histometric measurements were performed subjacent the sinus mucosa after 2, 4, and 8 weeks of healing. Results: Very few sinuses presented small percentages of new bone in close contact with the sinus mucosa in the various period examined. The presence of bone in the neighbor areas might have influenced bone formation close to the sinus mucosa. The inward displaced bone window supported bone formation
close to the sinus mucosa only in the earliest period of healing, while the bone walls increased their influence over time. The lack of increased new bone percentage over time in the most central regions of the elevated sinus mucosa do not support the hypothesis that the sinus mucosa may express its potential in bone formation. It can be speculated that the new bone found in the intermediate and middle regions of the control sites in the earliest period of healing might be due to residual of bone from the osteotomy. Conclusions: Very small amounts of new bone were found subjacent to the sinus mucosa, mostly formed from the bone walls, the inward displaced bone window or from possible
bone residues from the osteotomy procedures. The lack of increased new bone percentage over time in the most central regions of the elevated sinus mucosa indicates that the contribution to bone formation provided by the sinus mucosa is limited.doctoral thesi