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This paper presents three cases in which CSC telescope dentures were inserted following occlusion raising. Post-operative course remained uneventful in all three cases. Follow-up observations suggested that the use of CSC telescope denture, is helpful in prosthetic treatment which includes occlusion raising. In Case 1, occlusion was raised to a level above the free-way space. However, a new free-way space appeared after occlusion raising and it existed for a long time. A free-way space, which conformed to a space calculated from the free-way space before occlusion raising and the amount of occlusion raising, appeared in Case 2. In Case 3, however, the free-way space after occlusion raising was narrower compared to a space calculated from free-way space before occlusion raising and amount of occlusion raising.

The ability of hardness discrimination in 11 implant denture wearers was compared with those in 10 bridge wearers and 11 normal dentate subjects. The hardness discrimination was tested using silicone rubber blocks having rubber hardness that ranged at intervals of 10 degrees from 30 degrees to 70 degrees. Using a rubber block with rubber hardness of 50 degrees as a standard, the ability of discriminating rubber blocks of different hardness was examined. All the three groups examined had excellent ability of discriminating the rubber blocks of rubber hardness of 30 degrees and 70 degrees from the standard block. The ability to discriminate the rubber block of rubber hardness of 40 degrees from the standard block was only slightly lower than but almost the same as the ability of discriminating the hardness of 30 degrees and 70 degrees in all the three groups. However, the ability of discriminating the rubber block of rubber hardness of 60 degrees from the standard block was significantly lower in the implant denture wearers, compared to the normal dentate subjects and bridge wearers.

Cornell Medical Index (CMI), Manifest Anxiety Scale (MAS) and Yatabe-Guilford Character test (Y-G test) were carried out on 165 dental students in the course of clinical prosthetics to understand the psychological changes after study in this course. According to the Y-G profile patterns, in male students, the ratio of A, B, C, D, E and F types were 12.6, 6.7, 14.8, 63.0, 2.2 and 0.007%, and in female students, 6.9, 34.5, 17.2, 34.5 and 6.9% respectively. From the results of CMI, most of the students were stable after study in this course. Psychosomatic profile patterns of CMI before study were similar to those after in both sexes. All items of CMI were decreased in males, but some items were not decreased in females. Anxiety measured by MAS was decreased in many students but was increased in some students after study in this course. These results indicate that it is necessary to be concerned with the mental as well as physical well-being in unstable students.

Surface EMG activities in the masseter muscle were recorded from 8 healthy men with normal permanent dentition during habitual chewing of a small cube of synthetic cellulose sponge which had absorbed distilled water. Three parameters of chewing rhythm, viz., cycle time, duration, and interval, were shown as the respective averages of 40 measurements of the EMG traces of a masticatory series of 42 consecutive chewing strokes. Twenty-five recording sessions, in each of which the above masticatory series were repeated 10 times in a day with a 5 minutes' recess between each series, were performed on a subject during continuous 25 days. The amount of scatter in the distribution of 25 cycle time values was great at the 1st masticatory series, gradually decreased to reach a node relatively free from the dispersion at the 5th series, and then gradually increased from the 6th to 10th series. The same phenomenon was observed in all 8 subjects, although there was a small difference among them in the number of the series where the node was apparent. The average of 5 cycle time values was used to compare in the same subject the effect of chewing the cellulose sponge which had absorbed one of the 4 basic taste solutions with the effect of chewing that which had absorbed distilled water. The average value while chewing the sponge which had absorbed 1 M saccharose was significantly lower in the subjects who obtained a relatively large average value during distilled water sponge-chewing, whereas it was significantly greater in those who obtained a relatively small average value while chewing the sponge which had absorbed distilled water. The other 3 taste stimuli induced a significant increase in the average value in most subjects.

Filler contents, Knoop hardness, characteristics of cutting and surface texture of eight commercial composite resin cores were investigated. Two posterior composite resins and two silver alloys were used as controls. No differences were found in filler contents and Knoop hardness between the composite resin cores and posterior composite resins. In the composite resins, Knoop hardness was correlated to the filler content. The characteristics of cutting with a diamond point varied largely among materials. The composite resin cores were divided by deterioration of the characteristics of cutting into two groups. The degree of surface roughness of composite resins polished with a finishing diamond point was larger than that of the silver alloys. SEM examination revealed little differences in the composite resin surfaces cut with a diamond point but large differences in surfaces polished with a finishing diamond.

Antibacterial action of various denture base resins on thirteen species of bacteria were studied in vitro. Antibacterial effect of 5% tannin-fluoride preparation, 5% tannic acid and 5% chlorhexidine added to resins on these thirteen bacterial species were also investigated using heat-curing denture base resins. Fresh microwave-curing resin and pour-type resin each showed an antibacterial action on one bacterial strain. Fresh self-curing resins had antibacterial actions on several bacterial strains. However, after storage in water at 37 degrees C for one week, antibacterial action of microwave-curing and pour-type resin were diminished and self-curing resins partially lost their antibacterial actions. Denture base resin containing tannin-fluoride preparation or tannic acid showed an antibacterial effect on one bacterial strain. On the other hand, denture base resin containing chlorhexidine had an antibacterial action on eleven bacterial strains. However, color and mechanical properties of the drug-containing resins were not satisfactory.

The purpose of this study is to investigate the relation between the metal surface texture and bacterial adherence. The surface of Au-Ag-Pd alloy was treated with or without air-powder abrasion. Seven standard strains and two clinical isolates were used. The alloys were mixed with [6-3H]-thimidine labelled bacteria. The radioactivity was measured with a scintilation counter. Streptococcus sanguis and clinical isolated Bacteroides gingivalis were adhered in a larger amount to the air-powder abraded alloy surface than to nonabraded alloy surface. These results indicated that careful consideration is needed for application of air-powder abrasive system on metal crown with secondary caries and periodontal disease.

Maximum temperatures, time elapsed to reach them and setting times of four kinds of self-curing resins for rebasing were measured during polymerization at 37 degrees C with attention to curing conditions which might lead to the discomfort of patients in direct rebasing. The temperatures were lower and both times were longer than those of ones for making temporary crowns. When varying thickness of the resins, the maximum temperature and the setting time significantly increased depending on an increase in the thickness, although the time elapsed to reach the maximum temperature showed no difference. All values measured were remarkably influenced by pre polymer powder/monomer ratios.

Interdental dimension discrimination (IDD) ability in 11 patients with implant dentures was compared with that in 10 normal dentate subjects and bridge wearers. Using a 3.0 mm diameter wire as a reference, minimum perception difference between reference wire and test wires were measured at first molar region. In discrimination of thicker wires from reference wire, IDD ability was highest in normal dentate subjects followed by bridge wearers. It was lowest in implant denture wearers. In discrimination of thinner wires from reference wire. IDD ability was highest in bridge wearers followed by normal dentate subjects. It was lowest in implant denture wearers. A so-called "directional specificity", namely, higher IDD ability between thinner wires and reference wire than between thicker wires and reference wire, was recognized in normal dentate subjects and bridge wearers. However, there was no demonstrable directional specificity in implant denture wearers. On analyzing IDD ability in individual patients of implant denture wearers. IDD of both thicker and thinner wires from reference wire were approximately the same in 3 of the patients as those in normal dentate subjects and bridge wearers. In 7 patients, IDD ability of either thicker or thinner wires from reference wire was lower compared to the two other groups. In remaining patient, IDD of both thicker and thinners wire was impaired.