Periodontal probing of the gingival sulcus or periodontal pocket is one of the important clinical examination. There is a possibility that various pathogenic microorganisms may be transmitted from the diseased site to the healthy site with a periodontal probe.
The purpose of this study was to investigate the adherence of oral microorganisms to the different metal materials of periodontal probes in vitro. Four kinds of metal (austenite stainless steel 303 and 304, and martensite stainless steel 420 and 440C) were selected out of the stainless steel frequently used as metal materials of periodontal probes. Each metal specimen (φ=8mm) was prepared as having a various roughness.
Actinomyces viscosus, Streptococcus mutans and Streptococcus sanguis were selected and cultured. Each bacteria was put in sterile water and its density was adjusted at OD₅₅₀=1.0. Each metal specimen was incubated and shaked in 10cc of 0.049M Na₂SO₄ solution with bacterial solution (0.3cc) at 37°C for 5 hours (3cm/70st/min.). Attached bacteria to each metal specimen was stained with acridineorange solution and counted by Imura's modification method of Ørstavik et al. under an incident light fluorescence microscope. In addition the same procedure was carried out for metal specimens coated with human saliva after filtration (HA, 0.45μm pore size).
This study indicated the following conclusions:
1) All tested bacteria could adhere to all tested metal specimens.
2) There was the least number of bacterial adherence to austenite stainless steel 304 when compared to the other metals.
3) There was a decrease of bacterial adherence to all metal specimens treated with saliva coating (Particularly S. mutans to 420 and 440C metal specimens, and S. sanguis to 420 metal specimens).
4) There was no relationship between bacterial adherence and roughness of metal surfaces.

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The purpose of this study was to investigate the microbiological and clinical effects of subgingivally delivered chlorhexidine (CH)-containing strips. The strips were made of Hydroxypropylcellulose (HPC) and were dissolved in gingival crevice fluid. Five patients with advanced periodontal disease were selected for this study. Each patient had at least a pair of deep pockets contralaterally. CH-containing strips were applied in one pocket and placebo strips, which did not contain CH, applied in another pocket. Patients had no instruction in routine oral hygiene. Plaque Index (PlI), Gingival Index (GI), Pocket Depth (PD) and the presence or absence of Bleeding were recorded on day 0, 2, 4 and 6. Microbial samples from bottoms of pockets were taken by tuberculin syringes on day 0 and 6. And immediately they were cultured anaerobically, and were identified by Minitek (BBL).
Obtained results were as follows:
1. Total culturable numbers of facultative and obligate microbes in the pocket decreased in experimental sites (applied CH-containing strips) on day 6 (P<0.1).
2. The proportions of both Gram negative anaerobic rods and Bacteroides asaccharolyticus to the numbers of total anaerobes in the experimental sites were significantly lower than those of control sites (applied placebo strips) on day 6 (P<0.01).
3. The presence of Bleeding improved in experimental sites significantly (P<0.05), and PlI, GI and PD in experimental sites were lower than in control sites (P<0.1).
From these results, it was suggested that inserting CH-containing strips in pockets seemed to be a simple and useful method for improvement of periodontal con. ditions.

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The purpose of the present study was to clarify the mechanism of the fibrous attachment accompanied with the new cementum formation following flap surgery at the fine level. Three adult monkeys were used in a standardized flap operation; Mucoperiosteal flaps were made on the buccal aspect of 5 4/6 5|4 5/5 6 and elimination of alveolar bone approximately 2mm to the apical direction was performed. In order to expose the dentin surface, the root cementum was curetted. The surgical procedure and sacrifice of animals were scheduled to allow for observation periods of 2, 3, 4, 5, 6 and 8 weeks. The biopsies including the tooth, gingiva and bone were comparatively examined in light and electron microscopes.
The results obtained were as follows:
Light microscopical: Connective tissue reattachment to the dentin surface was observed two weeks postoperatively, subsequently the new cementum was deposited in the notch and the cementoid was also deposited on the dentin surface at three weeks. In the specimens obtained at longer intervals the new cementum formation took place coronally. Especially in the specimen obtained at six weeks, a considerable regeneration of the alveolar bone took place and the new cementum was also deposited from the notch to the termination of the junctional epithelium.
The resorption lacunae on the dentin surface were observed two weeks postoperatively as well as longer periods.
Electon microscopical: In early stage of healing, elongated fibroblasts were aligned parallel to and in close proximity to the dentin surface. Subsequently, the initial cementum, which were deposited over the dentin surface, consisted of individual collagen fibrils frequently running parallel or in a haphazard manner. As the new cementum increased in thickness, the superficial cementum was visible in well-defined fiber bundles. Cementoblasts were observed synthesizing collagen fibrils adjacent to the new cementum. A dense granular layer was present between the dentin surface and the regenerated connective tissue, or between the former and the new cementum.
In the resorption areas which arose on the dentin surface the dense granular layer was not visible when odontoclasts were actively involved in the dentin resorption. In accordance with reduction of the odontoclastic activity, collagen fibrils were quickly formed adjacent to the resorbed dentin surface and the dense granular layer was visible again. In these areas interdigitation of newly formed collagen fibrils with denuded ones on the resorbed dentin surface was observed, resulting in a more intimate union of the tissues.

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Eikenella corrodens aggregating factor (AF) was purified from human submandibular-sublingual (SM-SL) saliva, and the mechanism of E. corrodens aggregation with the AF was studied. The AF was purified from SM-SL saliva (secretor, blood group A) by ECTEOLA-cellulose column chromatography, ultrafiltration and gel permeation chromatography. About a 81-fold increase in the specific activity of purified the AF was achieved with a yield of 16.7%. Poly acrylamide gel electrophoresis of the AF in sodium dodecyl sulfate and β-mercaptoethanol produced single protein band corresponding to a subunit molecular weight of 140, 000. A molecular weight of 270, 000, 550, 000 and 2, 000, 000 was obtained by gel permeation chromatography in the presence of sodium thiocyanate. The AF possessed blood group A and H activities. Chemical analysis showed that the AF was sialo-glycoprotein containing 27% protein and 73% carbohydrate.
Galactosamine, glucosamine, galactose, fucose, and sialic acid were present in approximately molar ratio of 2:1:2:1:1.
Heating (100°C, 10min) or protease treatment of the bacterial cells abolished their capacity to aggregate with the AF. Protease treatment of the AF also abolished aggregating activity, whereas heating (100°C, 60min) was not affected. E. corrodens aggregation was inhibited by sugars containing N-acetyl-D-galactosamine and D-galactose. These results suggested that the aggregation of E. corrodens with the AF might require the interaction of lectin-like proteins on the bacterial surface with N-acetyl-D-galactosamine-like receptors on the AF.
The adherence of E. corrodens 1073 to human buccal epithelial cells was found to require the interaction of lectin-like proteins on the bacterial surface with D-galactose or N-acetyl-D-galactosamine-like receptors on the surface of epithelial cells. These two studies suggested that the adherence of E. corrodence to human buccal epithelial cells might be inhibited by the AF.

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Bone diseases, that is, bone changes, have been diagnosed by physiological evaluation by using the image of x-ray film, etc. as the object. The bone structure is in essence the periosteum, the cortex, and the bone marrow cavity. The bone marrow cavity is outlined on the film as a linear or nework bone trabecula. Therefore, if the density distribution of the bone trabecular pattern of the image is measured with a microdensitometer, then it forms a curve which changes randomly. Thus, we regarded the changes of the bone trabecular pattern on the image as a curve of one nonperiodical image which changes randomly. And the spectrum shows, when a curve which changes randomly is given, which frequency the components of the changes have and how much density the changes have, that is, the relationship between the frequency and the density of changes associated with that frequency.
We performed a quantitative evaluation of the bone trabecular pattern in conventional non-screen film imaging technologically. The results showed that the wiener spectrum method was effective for the quantitative asses of the bone changes sequentialy after bone graft materials were procedure d to the periodontal diseases.

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As a step for the investigation of biological characteristics of thick walled bacteria (TWB) existing in the deeper part of human dental plaque, a simple method was devised for the in vitro collection of TWB from the bacterial mass. It consists of the following three steps:
1) A bacterial mass contaminated with TWB found in the stock culture of Strep. mutans JC2 was inoculated into BHI broth for proliferation and the cultivation was continued until its optical density revealed stationary phase.
2) The bacterial mass collected by centrifugation of the above was suspendended in sterile water and left standing until its optical density became stable.
3) Then, the bacterial mass was again placed in BHI broth for cultivation until its optical density revealed stationary phase.
The bacterial mass in each of the above steps was subjected to various biological tests as well as electronmicroscopic observation. As the result, following points were clarified:
1. The TWB contained in the bacterial mass of the first step was only about 10%, but it became as high as approximately 70% by the end of the third step.
2. Elevation of the content of TWB to nearly 100% may be possible by repeating the procedures described herein.
3. When it is difficult to collect TWB in a sufficiently high percentage from the bacterial mass consisting of varying strains by conventional methods, the method described herein will easily enable to collect a large quantity of TWB.

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Fibronectin has a nature which combins with various components of biological and nonbiological substances by its specific molecular formula. On the assumption that fibronectin which has such physicochemical properties is contained in saliva, it may be conceivable that this substance not only adheres to the tooth surface as a component of aquired pellicle, but also aggregates bacteria and metalic ions, leading to formation of dental plaque and calculus.
This study was made in order to substantiate the assumption. And it has been clarified by gel diffusion precipitation and immunofluorescence technique that fibronectin exists in salivary glands, saliva and dental plaque, and its molecule increases gradually and becomes insoluble after secretion.
These results suggest that fibronectin is significantly related to the formation of dental plaque and calculus.

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Ultrasonic imaging equipment has been developed and applied to the examination of the periodontal tissues. By applying the 20MHz ultrasonic scanner of the equipment to the oral cavity directly, the equipment gives cross sectional images of the tissues with two planes perpendicular to each other. In this experiment, the maxillary anterior healthy periodontal tissues and the maxillary anterior and premolar periodontal tissues with periodontitis were investigated by ultrasonic tomograms and the distances between the marginal gingiva and alveolar crest were measured by the electronic caliper.
The results obtained were as follows: The tomograms of the periodontal tissues were displayed clearly and the distances between the marginal gingiva and the alveolar crest were coincided well with those measured directly in flap operation.
Then it was concluded that the ultrasonic imaging equipment was useful in diagnosing the periodontal lesion.

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The prevalence of periodontal diseases in 67 severely disabled patients (SDP) was investigated. The age of the patients ranged from 6 to 39. The intelligence quotient (IQ) of each patient was less than 30. Patients were diagnosed as cerebral palsy, Down's disease or congenital disbolism and hospitalized in a ward for SDP. Thirty four patients were administered antiepileptics and 19 of them received diphenylhydantoin (DPH).
The measurement of plaque index (Pl. I.), calculus index (C. I.), probing pocket depth (P. D.), bleeding index (B. I.) and salivary occult blood level revealed that the SDP had serious problem in maintaining healthy periodontium. Calculus Index, B. I. and salivary occult blood level of the patients, aged between 20 and 29, were significantly higher than the group, aged between 10 and 19. Patients of DPH group had higher C. I., P. D., B. I., and salivary occult blood level than non-DPH group.
Most of the patients received a brief oral hygiene procedure, once a day, with a tooth brush which was performed by a nurse. Meals for the patients were mainly consisted of soft food and the masticatory movents of the patients were limited. This must be one of the causes for obtaining such high scores in clinical examinations in SDP.
An effective and simple procedure must be developed to establish good oral hygiene in SDP.

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The objective of this study was to search for evidence of antibody dependent cell-mediated cytotoxity (ADCC) that might relate to periodontal tissue destruction.
We investigate ADCC in vitro against fibroblastoid cells derived from human normal gingival tissue and the presence of K cells in infiltrated cells from human gingival tissues with periodontitis. Fibroblastoid cells binding Eikenella corrodens were lysed by normal human peripheral blood lymphocytes (PBL) after presensitization with rabbit antiserum to the bacteria. In infilterated cells obtained from the human inflamed gigival tissues by enzymatic treatment, Fc receptor (FCR) bearing cells were detected by IgG-EA rosettes formation. These cells, however, exhibited no ADCC activities against sheep erythrocytes as targets. Human PBL in positive control group and rat infiltrated cells from experimental inflamed lesion showed significant ADCC activities. But these cells did not mediate ADCC after enzymatic treatment, even though similar proportion of the cells bearing FcR before and after the treatment in human PBL.

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The purpose of the study was to make quantitative observation of lower first molar furcation and examine the fitness of furcation probe on it. 100 periodontally involved extracted lower first molars were used for the study. Lengths were measured partially using caliper directly on the teeth furcation and partially on the traces. Fitness of furcation probe was examined on bucco-lingual furcation area after being traced.
Results are as follows. Average bucco-lingual crown width of first molar was 10.7mm. Average bucco-lingual furcation width was 8.4mm. Average length measured from base of furcation to CEJ-line was 1mm shorter on the buccal side compared to lingual. Enamel projection was more frequent in buccal than lingual. Various furcation probe was tried from buccal side, but none proved to be effective to penetrate from buccal side to the lingual. So penetration was made either from buccal or lingual side individually until it reached the deepest area of furcation. Curved probe with 7mm radius of curvature was best fitted on the buccal side and 8 mm radius on the lingual in more than 96% of cases. Coronal reference point was made on buccal groove (CRP-B) and lingual (CRP-L) separately at its most coronal point. Length of probe from CRP-B to the entrance of buccal furcation was 9±1.1mm and that from CRP-L to lingual was 8.8±1.0mm. Length from CRP-B and CRP-L to the bottom of furcation area was 13.5±0.9mm and 13.3±1.1mm respectively.

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