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ミリング型セラミックインレーシステム"セレイ"の評価 第1報 製作方法と操作性について
Get PDFapplication/pdfAs the demand for aesthetic restorations has increased in the past few years, tooth color materials have been used frequently in posterior teeth. Ceramics are widely used as dental restorative materials because of their excellent properties. A number of the devices making ceramic restorations have been developed and marketed, and CELAY system is one of the newly developed ceramic inlay systems. CELAY system has a character in its making procedure, which means a ceramic inlay is made in a short time from a ceramic block by a milling technique. The purpose of this study was to examine whether CELAY system can easily make ceramic inlays or not. Twenty extracted upper premolars were used. Only one clinician prepared all twenty box-shaped class II (MO) cavities to make the cavities uniform. Then each of five ceramic inlays were made by four clinicians whose length of clinical experience differed. The neccesary time to, 1) make a proinlay, 2) fit the proinlay to a scanning area, and 3) mill the ceramic block to the ceramic inlay, were measured. The following results were obtained; 1) The average time for producing a proinlay was 8 minutes 44 seconds (S. D. 1 min. 39 sec.). 2) The average time to fit a proinlay to a scanning area was 3 minutes 49 seconds (S. D. 1 min. 22 sec.). 3) The average time to complete milling was 18 minutes 17 seconds (S. D. 4 min. 6 sec.). Statistical analysis showed significant differences among clinicians (P<0.05), but not among length of clinical experience. 4) The total average time to make a ceramic inlay completely by CELAY system was 30 minutes 50 seconds (S. D. 4 min. 29 sec.). It may be concluded that CELAY system is able to decrease labor and time to make the ceramic inlay as compared with the conventional biscuit method, and if it is carried out in accordance with the manufacturer's instructions, the beginner can also make the ceramic inlay easily.journal articl
矯正保定期間中に顎関節症が生じた症例
Get PDFapplication/pdfOne case of temporomandibular disorder appearing during a retention period was reported. It was detected by an oral examination that the patient had premature contact and occlusal interference in the right molar region. For this reason, the patient had a discrepancy in location between the centric position and the centric occlusion. The patient discomfort and pain were located in the temporomandibular joint area. This centric position of the patient was transferred and reappeared on a semi-adjustable articulator. Premature contact and occulusal interference were detected on the articulator. By referring to the data from the articulator, occlusal equilibration was performed on the patient dentition. We believe that dysfunction was cleared up and that occlusion became satisfactory, and tooth position justified the usage of an occlusal adjustment. Since that time, there has been improvement in the function of the dentition and occlusion.journal articl
歯周病患者の統計的観察 第6報 昭和61年～平成元年における初診時質問表について
Get PDFapplication/pdfIt is very important to consider the condition of patients prior to periodontal treatment. The authors investigated questionnaires filled out by 427 periodontal patients (207 males and 220 females) during their first visit to the periodontics department of Matsumoto Dental College Hospital between 1990 to 1992. The questions related to age, chief complaint, favorite food, habits, periodontal treatment experience and systemic diseases. Results were classified by sex and age. The results were as follows: 1. There were several male patients in the 40～49 year-old age group. 2. In most cases the chief complaint was food impaction. 3. Among the 50～59 year-old male patients, responses to favorite food included drinking and smoking. 4. The 50～59 year-old patients had the greatest experience with prior periodontal treatment. Scaling had been done on 49.6% of them. In most cases their brushing was two times per day. 5. With regard to habits 44.5% of patients snored and most of these were male. 6. Many of the 50～59 year-old patients had hypertension, although this figure was higher in the 40～49 year-old patients.journal articl
レーザ溶接したチタンの浸漬溶液中における機械的性質の経時的変化と溶出について
Get PDFapplication/pdfThis study investigated tensile and releasing properties of titanium samples which were laser welded, plasma welded, and infra-red soldered after immersing test. The main results obtained are as follows; The insertion of a titanium foil was effective to prevent volume reduction during the welding process. It was found that the laser welding reduces tensile properties, especially toughness, and elongation when the samples were immersed and shaken in a physiological saline and in a lactic acid prior to the laser welding. It was also found that, even self-welded titanium samples would be embrittled when they were placed in a corrosive environment over a long period of time. The magnitude of these reductions was more significant with the silver soldering than those with titanium soldering. No evidence of titanium released from the welded portion was observed in a physiological saline, but the released amount of titanium from the welded portion was higher than that from the base metal when it was exposed to a lactic solution. After a silver soldering, a trace amount of titanium was released in a physiological saline after a 6-month immersion test, and the lactic acid's released titanium was remarkably greater with the laser-welded samples. In addition to titanium, it was observed that copper and zinc released from the soldering material were detected in larger amounts.journal articl
Effect of Mold Temperature on the Titanium Casting
Get PDFapplication/pdfThe purpose of this study was to evaluate the titanium castability with a vacuum pressured type casting machine. We tested ethyl-silicate bonded investment "TITAVESTPS" of metal frame work. Four different mold temperatures (room temperature, 300℃, 600℃, and 900℃) were prepared for the present study, and casting was done in five times in each condition. When the mold temperature increased, high percentage of castability was gained. Mold temperature showed a highly significant (p<0.001) correlation on the castability. These results indicate that high performance of castability on the titanium was achieved when the mold temperature increased by using vacuum pressured type casting machine.journal articl
幼若永久歯の口腔清掃に関する研究 : 第1報 下顎第1大臼歯の歯垢分析について
Get PDFapplication/pdfThe immature teeth, especially the first permanent molars show a high caries rate with plaque accumulation. Plaque accumulates easily on newly erupted first permanent molars because of its anatiomical structures, complicated eruption processes and shortage of self-cleaning action. In this study, according to the eruption status of the mandibular first permanent molar, 42 children with the newly erupted molars were divided into 3 stages. Plaque distribution was investigated by using a special camera which was designed by the author et al. According to the photos, plaque distribution on the molars was evaluated and analyzed statistically by computer. Results were as follows: 1. On the different eruption stages: Plaque accumulation was highest in the early eruption stage and decreased as the molars erupted. Significant difference was found between eruption stage 1 and stage 2. 2. On the occlusal surfaces (mesio-part, central-part and distal part): Plaque accumulation decreased on the each part of the occlusal surfaces as the molars erupted. 3. Plaque accumulation on buccal surfaces of the molars was found to decrease as the molars erupted. Significant difference was found among each of the eruption stages. 4. As the molars attained occlusal position, plaque accumulation had a tendency to decline. 5. There was no relationship between the subjects with TBI experience and without it, however, plaque accumulation decreased as the molars erupted.journal articl
カテコール-O-メチル基転移酵素の免疫組織学的局在 : 口腔組織との関連
Get PDFapplication/pdfCatechol-O-methyltrasnferase (COMT) catalyzes the transfer of a methyl group from S-adenosyl-L-methionine to one of the phenolic hydroxyl groups of a variety of catechols. This O-methylation reaction is important in the enzymatic inactivation of circulating catecholamines, the enzymatic inactivation of 2-hydroxyestrogens, the detoxification of xenobiotic catechols and the local inactivation of catecholamines released as transmitters from the terminals of both central and peripheral catecholamine-containing neurons. Many studies have shown that COMT is widely distributed in animals' tissues with the highest levels present in liver and kidney. COMT is an intracellular enzyme that is present predominantly in a soluble form with lesser amounts bound to membrane or microsomal fraction. Several specific antibodies to COMT have been available. Those permit us to examine the localization of COMT in the various organs of animals. COMT-positive cell was observed in the adrenal gland, brain, dental pulp, ductus deferens, gastrointestinal tract, eye, kidney, sublingual gland, liver, lymph node, mammary gland, ovary, oviduct, pancreas, parotid gland, pituitary gland, seminal vesicle, spinal cord, spinal ganglia, spleen, submandibular gland, sweat gland, thymus and uterus. COMT-positive reaction product in reactive cells was diffusely present throughout their ccytoplasm, but was absent from the nucleus. In the rat salivary gland, the myoepithelial and striated duct cells contained COMT. COMT was present in the macrophages like cells in the rat dental pulp. The possible functions of COMT in vivo have become more apparent with the expanding knowledge of the specific cellular localization.journal articl
下顎前突症患者の顎関節症状に関する検討
Get PDFapplication/pdfWe conducted a follow-up and a questionnaire survey concerning the incidence of temporomandibular joint (TMJ) disorders in 66 patients who had been operated on by sagittal split ramus osteotomy in the Department of Oral and Maxillofacial Surgery II of the Matsumoto Dental College within last ten years. A questionnaire was made to all patients during follow-up of 51.1 ±32.5 months (ranged 13-103 months) after operation. Responses were received from 33 patients, who had not been treated for the TMJ disorders. The questionnaire of a self evaluation form included items regarding of present symptoms of the pain and sound. The difference of incidences of the TMJ disorders between wire osteosynthesis and bone screw fixation was not statistically significant. In patients in which there was right-left difference of the amount of the posterior transfer of the corpus mandibulae, the incidence of TMJ disorders at one month after the release of the intermaxillary fixation was significantly higher than that before the operation, regardless of wire or bone screws.journal articl