The sensory threshold effects of the mouth odors may be dependent on or concurrent with the interaction among the odor components. It is a fact that when we add physically two odorous substances, the judgements of intensity of the mixtures do not simply represent the sum of the judgement made to either of the components alone. From previously published studies, the components of the halitosis had been demonstrated by gas chromatography but the sensory thresholds of the mixtures present only in restricted sensory evaluation. The relationship of the concentration and the sensory thresholds of the halitotic components was important to qualify the halitosis.
In the present study, the author was concerned with the sensory evaluation method by selecting five halitotic components-Hydrogen Sulfide, Methylmercaptan, Dimethylsulfide, Methylamine and iso-Valeric acid, and combining freely two among them to research the interaction between each of the two-component mixtures. The concentration of the odorants was estimated by gas chromatography. And the sensory evaluations were performed by 6-8 from 50 screening panelists with the olfactometer under the established circumstances, in order to find out the Population Perception Threshold 50% (PPT₅₀) through the Mills'Odor Response Chart.
The odor results of the Binary Combinations were calculated and analyzed. The data were treated as described and led to the following conclusion.
(1) Odor mixtures of Hydrogen Sulfide & Methylmercaptan, Hydrogen Sulfide & Methylamine and Methylmercaptan & Methylamine show suppressive tendency of the threshold.
(2) The mixture of Hydrogen Sulfide & iso-Valeric acid may indicate additivity.
(3) The addition of Hydrogen Sulfide, Methylmercaptan, Methylamine or iso-Valeric acid into Dimethylsulfide may show some synergism in the threshold sensation of the mixtures.
(4) As Methylmercaptan or Methylamine is combined with iso-Valeric acid the synergistic phenomena are comfirmed in the threshold sensation of the mixtures.

抄録全体を表示

Bacterial glycosidases that cleave carbohydrate components from salivary glycoproteins may be important in oral pathological conditions. The purpose of this study was to survey for the presence of extracellular glycosidases of some oral streptococci.
Twenty-four strains of oral streptococci were grown in trypticase soy broth culture at 37°C for 24 hours.
The extracellular enzymes in the supernatant of culture were precipitated by the addition of 80% saturation of ammonium sulfate and then dissolved in phosphate buffer (pH 7.0). For the assay of α-L-fucosidase, porcine submaxillary glycoprotein (PSG) and/or p-nitrophenyl-α-L-fucoside (p-NPF) were used as substrates. Neuraminidase activity was determined using human plasma glycoprotein Fr. VI. Using corresponding p-nitrophenylglycosides, other glycosidase (β-galactosidase, β-N-acetylglucosaminidase, α-mannosidase) assays were performed. The free sugar and p-nitrophenol released, each was determined by the spectrophotometric method, respectively.
Both activities of α-L-fucosidase against PSG and neuraminidase were found only in S sanguis ATCC 10557 and S. mitis ATCC 9811. α-L-Fucosidase activity against p-NPF was not detectable in any strains. Several strains of S. sanguis possessed both β-galactosidase and β-N-acetylglucosaminidase activities. Only one strain in S. mutans tested produced β-N-acetylglucosaminidase.
This study has demonstrated that bacterial glycosidases are produced by some oral streptococci. It is tempting to speculate that the streptococcal glycosidases may play a role in the degradation of salivary glycoproteins.

抄録全体を表示

Dextranase labelled with ¹²⁵Iodine was applied by means of a radioimmunoassay to detect any change in the permeability of the oral mucosa under test.
For the purpose of this experiment, two groups were selected:
Group one contained three individuals with clinically healthy gingivae.
Group two contained six individuals with periodontally diseased gingivae.
The treatment was undertaken using different concentrations of the dextranase solution. The maximum effective concentration was twenty five nano-grames of dextranase to one millilitre of water (25ng/ml) (B/Bo=90 percent)
There was no remakable change in the condition of either the control or the diseased cases. Nor was there any significant improvement in the cases with periodontally diseased gingivae. Moreover, the dextranase was not found to cause any senitive reaction in the human body.

抄録全体を表示

Human gingival fibers and periodontal membrane fibers were observed scanning-electoronmicroscopically. The results obtained were as follows:
1) In the gingival fibers, the folds which are relatively similar in form cross at right-angle to the tooth and the extention of fibers between the cementum and the gingiva were observed.
2) The periodontal membrane fibers were generally consisted of the following three types; the first, relatively thick fibers which crossed between the cementum and the alveolar bone, the second, thin fibers which were observed mainly around the cementum and run parallel to the tooth, and the third, curtin-like close fibers which were located at the middle of the periodontal membrane and were observed streching like a spider's web in the strong magnification.
3) At the cementum, the ends of the periodontal membrane fibers of which brunch like roots and bury into the cementum were observed.
4) Some erythrocytes were observed on the cementum and the periodontal membrane fibers.

抄録全体を表示

This experiment was designed to study the osteogenetic property in implants of allogeneic decalcified bone matrix gelatin. Long bones, excised from adult rats, were cut in length of 4mm and treated sequentially. Extracted conditions were: 0.6N HCl, 24hr, 4°C; 8.0M LiCl, 24hr, 4°C; distilled water, 4hr, 55°C. After lyophilization, decalcified bone matrix gelation were implanted in subcutaneous pouch of allogeneic recipients, and recovered for histologic and roentogenographic examination. The implanted matrix somehow induced migratory mesenchymal cells to differentiate into cartilage at 2 weeks, and to remodel and replace the deposits with lamellar bone and marrow between 3 to 4 weeks. The travecular interstices and old vascular channels were chiefly invaded with mesenchymal cells and histiocyte-like cells. Multinucleated giant cells were not detected. As calcification proceeded, area and intensity of von Kóssa positive reaction were increased, whereas toluidine blue metachromasia and alcian blue positive region were reduced, and finally disappeared when ossification was completed.

抄録全体を表示

Trauma from occlusion has been considered an important factor of periodontal disease. Tooth clenching which closes the jaws involuntary under heavy pressure is recognized to produce a great destructive force.
We must correctly judge whether patients have the habit of clenching for treatment of periodontal disease.
However, patients are usually unware of the habit and dental science has not yet developed accurate creteria for diagnosis of clenching as of the present moment. The purpose of this study was to relate the cheek pressure, cheek indentation, and EMG of masseter muscle for clarifying the subject of clenching.
The experiments were carried out on 7 subjects from 28 to 45 years. When clinically examined, they seemed to have the habit of clenching, and tooth indentation was recognizable on cheek mucosa. Buccal pressure in the upper first molar and premolar region, and electrical activity of the masseter muscle were messured at: (1) rest, (2) saliva swallow, (3) water swallow, (4) voluntary clenching (closing the jaws voluntarily), and (5) emotional stress.
The results and conclusion were as follows:
(1) At rest; increase of cheek pressure was recognized during involuntary swallow, but occasionally between each involuntary swallows.
(2), (3) During saliva and water swallow (voluntary swallow), cheek pressure was appreciably increased in all subjects.
(4) During voluntary clenching, electrical activity of the masseter muscle was recognizable, but cheek pressure was not remarkably increased.
(5) During emotional stress, cheek pressure increased more than rest in four subjects. These phenomena seems to be identifiable in the tension of the orofacial muscles by emotional stress.

抄録全体を表示