A solid surface usually makes clear interface against a biological system, such as cell and tissue; the interface works as a barrier for transportation of molecules and conduction of biofunction. Thus, to create unclear and graded interface at which molecules smoothly transport, both material and tissue are integrated together, and biofunctions are conducted, many researches have been performed. When titanium is implanted into bone, bone tissue forms on it faster and the bonding strength is clearly stronger than other metallic materials. Therefore, titanium shows the best hard tissue compatibility among metallic materials. Many surface treatment techniques are investigated to improve tissue compatibility of titanium, while most of them are for improving hard tissue compatibility. Commercialized surface modification techniques are mainly to form roughened or porous surfaces, while immobilization of biofunctional molecules is hardly commercialized at present. To increase the performance of a material, the characterization of the material itself and discussion on the relation between the biological reaction and property of the material, are mandatory. In addition, to commercialize the material, the evaluation of the safety, durability, and conservation of the material and the surface treated layer is essential.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Purpose: The short-form oral health impact profile (OHIP-14) is an effective tool for measuring oral health-related quality of life (OHRQoL). It is reported that the OHIP-14 is associated with oral condition and function, but there are few reports on the relationship between OHRQoL and psychophysiological background. In this study, we investigated the relationships between the OHIP-14 and oral condition, and social and psychophysiological backgrounds.
Methods: Community-dwelling older adults (N=177; mean age: 74.6±4.2 years) were recruited in this study. An intraoral examination was carried out to assess their oral condition. The subjects were interviewed based on a questionnaire about their gender, age, general health, oral health, social background, the Philadelphia Geriatric Center (PGC) morale scale for subjective well-being, the Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI) as a personality test and the OHIP-14. Multivariate logistic regression analysis was employed to estimate the associations between the OHIP-14 scores and the parameters of the oral condition, social and psychophysiological backgrounds.
Results: In multivariate logistic regression analysis, self-rated oral health, tongue pain, number of remaining teeth, and PGC morale scale were significantly associated with lower OHIP-14 scores.
Conclusions: These results suggest that OHRQoL may be associated with oral condition and social and psychophysiological backgrounds in community-dwelling older adults.

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Purpose: The purpose of this study was to evaluate an appropriate jaw opening by an oral appliance for patients with obstructive apnea syndrome.
Methods: Eighteen normal dentulous subjects without stomatognathic function were enrolled in this study. The subjects were divided into two groups (low ODI group: 13, high ODI group: 5) by Oxygen Desaturation Index (ODI) (cut-off score=5). To assess the changes in ventilation, the forced inspiratory flow (FIF_25-75) was measured using a spirometer for four kinds of jaw opening (0 mm, 5 mm, 10 mm and 15 mm) with the position of 50% jaw protrusion. The airway morphology of all the subjects was also imaged by magnetic resonance imaging for the same four kinds of jaw opening and centric occlusion as a control. The upper airway volume from the upper point of the soft palate to the base point of the epiglottis and the antero-posterior distance of the upper airway at the most posterior point of the soft palate were measured and evaluated.
Results: Although FIF_25-75 increased with jaw opening in both groups, a similar tendency for airway volume was not observed. There was no statistically significant difference between the two groups. In addition, the volume change of the upper airway occurred mainly at the upper part.
Conclusions: It is suggested that it is better to decrease unnecessary jaw opening to reduce discomfort for OSAS patients.

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Patient: The patient was a 68-year-old woman who came to our hospital complaining of a masticating disorder due to loss of a mandibular removable partial denture. The remaining teeth of the maxilla were the right second premolar and second molars on both sides. A maxillary removable partial denture had been set at the site of the defect. The mandibular right second premolar, and first and second molars on both sides were missing. A removable partial denture was manufactured by the traditional method and fitted to the mandible. The tongue movement during mastication was observed using ultrasonography, and was classified into the early, intermediate, and final periods from the M-mode waveform. Then, by tracing the B-mode coronal images at the lowest points of the M-mode for five consecutive waveforms of each period, we measured the distance to the surface of the mandible skin from two points on the surface of the tongue in the left and right sides 15 mm away from the midline. The difference in height between the left and right sides of the tongue was observed before and after treatment. Movements were chewing on one side of the left or right. The test food was 10 g of cooked rice. Tongue movements were observed before treatment, and at 1 and 6 months after treatment.
Discussion: The difference in height of the tongue did not change in each period before treatment, but showed a decreasing trend with the progress of mastication at 1 and 6 months after treatment. Furthermore, at 6 months after treatment it was similar to the clinical reference value of dentate elderly.
Conclusion: In this case, it was considered that tongue movement during mastication adapted to the environment by chewing denture in about 6 months, and that wearing dentures affects tongue movement during mastication.

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Patient: The patient was a 56-year-old woman whose chief complaints were instability of a maxillary denture, pain in the mandibular ridge and mastication disorder. Instability, pain and mastication disorder occurred owing to severe maxilla alveolar ridge resorption with a flabby gum and discrepancy of maxilla-mandible alveolar ridge morphology. Thus, blade teeth were selected to solve these problems when fabricating a new set of complete dentures.
Discussion: By using the neutral zone technique and blade teeth, decreased horizontal movement of the denture and improvement in mastication disorder were obtained. As a result, an improved outcome was obtained.
Conclusion: Improvements in chief complaints and positive outcomes were obtained by designing new dentures to combat lack of stability and retention.

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Patient: The patient was a 70-year-old male with the chief complaints of masticatory disturbance and an esthetic problem with a maxillary complete denture. The left canine was added to the maxillary partial denture as a complete denture and it was discolored and ill-fitting to the residual ridge. We relined the dentures and made both the new complete dentures with cast reinforcements.
Discussion: By embedding the cast reinforcement, the complete dentures become more rigid and could decrease denture deformation. As a result, denture fracture, deformation and ridge resorption could be prevented.
Conclusion: A cast reinforcement of the denture base can make the denture more rigid and prevent various problems after denture insertion.

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Patient: A 68-year-old male presented with the chief complaint of pain during chewing in the left molar region of his mandible where there was a partial denture. He underwent oral rehabilitation with a crown restoration and removal of the partial denture to treat disturbances in the occlusal plane in the case of non-vertical stop malocclusion.
Discussion: When both a crown prosthesis and a prosthesis for missing teeth are to be used, occlusal registration needs to be performed twice: once during crown restoration and again during denture fabrication. In such cases, denture and occlusal stability can be achieved by performing occlusal registration in the same occlusal position of the maxilla and mandible.
Conclusion: The combined use of a crown prosthesis and a prosthesis for missing teeth created for the oral cavity as a whole enabled oral rehabilitation that removed disturbances in the occlusal plane.

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Patient: A 62-year-old female patient presented with chewing difficulty and a request for good esthetics. The occlusal function was severely compromised because of increased mobility of the posterior dentition. Following the extraction of hopeless teeth, partially edentulous arches were restored with a maxillary nine-unit fixed restoration and maxillary and mandibular bilateral free-end saddle dentures.
Discussion: The oral health-related quality of life and subjective chewing ability were improved and high patient satisfaction was reported after the definitive prosthodontic replacements. The results were partly due to the effects of reconstructed occlusion by the fixed splinting and removable partial dentures that were rigidly retained in the maxillary and mandibular arches by the Co-Cr precision frameworks. The periodontal tissues and restorations have been maintained for more than 3 years.
Conclusion: Periodic post-operative recalls suggest that a combination of a long-span fixed bridge and removable partial dentures functions well for the partially edentulous patient with advanced periodontitis.

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Patient: A 54-year-old man visited the Department of Fixed Prosthodontics, Osaka University Dental Hospital with the complaint of mastication dysfunction because of dental caries in lower bilateral molars. In this case, implant treatment was applied for lower bilateral and upper left molars. The maxillary right molar region was treated with metal-ceramic restorations.
Discussion: The patient was followed for 4 years 6 months. His dental implants and restorations remained in good condition due to improved plaque control.
Conclusion: It was possible to obtain the patient’s satisfaction with restored esthetics and masticatory function. This suggests the importance of plaque control in order to continue the therapeutic effect in this case.

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