History and definition of diabetes mellitus were reviewed. Diabetes mellitus is characterized by complications of widespread organs resulting from chronic hyperglycemia. Increased sorbitol production via the polyol pathway and glycation of proteins coupled with hemodynamic changes contribute to the development of diabetic complications. Diabetic angiopathy constitue a characterstic capillary lesion, capillary microaneurysm, which proceeds to diabetic retinopathy and nephropathy. Involvementt of capillary vessels by diabetic angiopathy should be considered, when diabetic foot and periodontal disease are ought to be treated.

  Feline immunodeficiency virus (FIV) was first isolated from a cluster of cats with suspected immunodeficiency syndrome. The genetic studies have confirmed that FIV is an innate virus with some homology to human and simian immunodeficiency viruses. Furthermore, FIV fails to grow in other mammalian cell cultures including human, but grows in feline peripheral blood mononuclear cells, kidney cells and interleukin 2 dependent T-cell lines. Infection of cats with FIV results in five distinctive clinical stages similar to those observed in human immunodeficiency virus (HIV) infection. Following acute phase and asymptomatic carrier phase, a number of chronic diseases occur in infected animals, and the clinical manifestations are closely associated with development of immunodeificiency as measured by lymphocyte subset studies or by blastogenesis assay. The advantage of this feline system as an animal model for human AIDS includes ease of experimental infection using specific pathogen free cats with a relatively smaller cost and space, safety to other species including human, and similar clinical manifestations as well as the virologic relations. The safety is a major consideration in carrying out large scaled screening studies. Thus, basic pathogenesis studies and drug therapy screening will be the major fields that this system potentially can contribute to the human medicine.

  Noticeable bone mineral density (BMD) change would be detected as losses of 30-50 % from standard radiographs. Spinal BMD measurements by computed tomography (Quantitative CT) may be made using a mineral calibration phantom precisely and accurately. In man the normal mean value of BMD is shown linear regression and is reduced over 40%. In females the normal mean value of BMD is shown cubic regression, accelerated at menopause, and is reduced over 50%. Calcium intake is necessary 600mg to 1,000mg per day, but in Japan calciumu intake is under 600mg per day. Moderate exerceise and intake of calcium are essential to preventing fractures by osteoporosis.

  A comparison of the effects of newly-developed root canal sealer and commercially available sealers of a cultured human periodontal ligament fibroblastic (HPLF) cells was done in this study. Various root canal sealers were applied to cultured HPLF cells obtained from premolars extracted for orthodontic reasons. Measurement of [H³]-thymidine incorporation and alkaline phosphatase activity was carried out after 24 and 48 hrs.. No significant difference was observed in cellualar DNA synthesis and alkaline phosphatase activity of cells exposed to No.1, No.5, No.6, Canals-N and controls at 24 and 48 hrs.. Canals and Diaket significantly inhibited DNA synthesis and alkaline phosphatase activity at 24 and 48 hrs.. Sealapex had no inhibitory effect on DNA synthesis and alkaline phosphatase activity at 24 hrs., but Sealapex showed inhibitory effect at 48 hrs.. Newly-developed root cadal sealers demonstrated lower toxicity than canals and Diaket in vitro.

  The purpose of this study was to investigate the relationship between the cavity preparation form and the pulp chamber of deciduous molars.

  The materials were nondecalcified 323 serially ground specimens which were prepared mesiodistally and buccolingually from 40 extracted deciduous molars. PARAREROMETER PARAFIX 78 (MORITA COMPANY) was modified as a standard cutting instrument for cavity preparation. With this standard cutting instrument, Class Ⅰ (G.V.BLACK's classification) cavities were prepared. The depth of the cavity was standarized to 0.5mm from the enamel-dentin junction to the cavity floor at the center of the central groove and the center of the central fossa.

  The results showed that the cavity floor did not lie in the enamel but in the dentin in all of the observation areas and the depth of the cavity tended to be deeper at the mesial and distal sides than at the center of the central groove and at the center of the central fossa. The distance from the cavity to the pulp chamber tended to be shorter at the lingual side than at the buccal side, and also tended to be shorter at the mesial side than at the distal side.

  It was shortest at the mesio-buccal side. The minimum distance from the cavity to the pulp chamber was 0.37mm at the buccal wall of the mesial marginal ridge in the upper first deciduous molar, and 0.66mm at the distal wall of the buccal groove in the upper second deciduous molar, and 0.48mm at the buccal wall of the mesialmarginal ridge, 0.50mm at the distal torigonid ridge and 0.51mm at he center of the distal torigonid ridge in the lower first deciduous molar, and 0.67～0.74mm at the mesial marginal ridge and at the mesio-buccal groove (0.96～0.97mm) in the lower second deciduous molar.

  Two male patients aged 58 and 38 years mainly complained of pain in and around the unilateral ear. Upon completion of a TMJ examination in prosthetics or oral maxillofacial surgery, they were diagnosed as the TMJ arthrosis and then the dental routine treatment had been carried out there over a half year period. But the pain didn't disappear by their consultation and treatment. An Endodontist performed a pulpectomy of ⌈7 for this case 1, and soon the pain disappeared. In those two cases, a wide mesio-distal fracture through the tooth and abscess formation at the buccal gingiva were seen approximately 7 to 8 months later after the first visit.

  After the extraction of the teeth, the pain disappeared rapidly. They haven't relapsed for 18 months in the case 1 and 8 years and 2 months in case 2.

  Undecalcified ground sections cut in a bucco-lingual longitudinal direction of the extracted tooth in the case 1, revealed that the thin zone along the fracture line tended to appear radiolucently in CMR, and that there were mass granulomatous tissue around the fracture line at furcation site.

  In both cases, the teeth were noncarious and the crowns had severe attrition. The patients had well grown muscles of mastication and the habit of crunching hard foods with molars. It seemed that the excessive occlusal pressure for a long time caused a crack or fracture of tooth and that the following chronic pulpitis caused with referred pain.

  The objective of this study was to evaluate the effect the citric acid solution as a root canal irrigant by using ultrasonics.

  Extracted human single rooted teeth were instrumented using K-file, size #10～60 with NaOCl. The outside of the apical third of the roots were covered with utility wax to prevent irrigation through the apical foramens. After that, the teeth were randomly assigned into 6 groups. And the teeth were placed in a plaster blocks.

  Group 1 was irrigated by 1 Mol. citric acid for 30 and 60 seconds. Group 2 was irrigated by 0.5mol. E.D.T.A. for the same period of time. Groups 3 and 4 were irrigated by ultrasound (ENAC 6) with 1Mol. citric acid (group 3) and 0.5Mol. E.D.T.A. (group 4) respectivily. In groups 5 and 6. root canals were irrigated by the ultrasound (ENAC 6), while using ultrasonic vibration (Suprasson P3) from outside of teeth, with 1Mol. citric acid (group 5) and 0.5Mol. E.D.T.A. (group 6) respectively.

  The control using distilled water was also provided to all groups. After the final irrigation, the teeth were dried and sectioned horizontally Partitionuol into three at the junction of the apical and middle thirds. Then the apical third was transversely partitioned. The apical third was mounted onto a brass stub and given a minimum thickness gold coating and viewed in S.E.M. The results showed that dental tubes of the group 5 were more evidently seen than other groups. It was thought that using ultrasonics from inside and outside of the tooth produced much cleaner canal walls and activated citric acid irrigation ability of the smear layer.

  In dental treatments like extractions, implants, another surgeries, and periodontic and endodontic treatments where bleedig is present, contamination by aerial bacterias or dust particles of the environment is possible.

  In dental office there are many people coming in or leaving, patients; dental technicians, dental material salesmen, medicine salesmen, etc., and all of them bring a lot of aerial bacterias and dust particles from other places. Therefore, we must keep clean our dental office every moment.

  This time, I have taken the measurement of aerial bacteria and dust particles with the Membran Filter Method and the Laser Particles Counter after complete cleaning of the dental office using the home-use air cleaner.

  The results proved that the place was as clean as the Clean area.