This study was designed to investigate diagnostic methods for measurement of periodontal disease activity. Subgingival plaque and gingival crevicular fluid (GCF) were taken from active and inactive lesions in 10 subjects with untreated adult periodontitis and also from 7 subjects in whom periodontitis was maintained after periodontal treatment. Active disease sites were defined as pockets showing more than 2 mm loss of connective attachment during 42-day monitoring without periodontal treatment and a recall period, respectively. Inactive disease sites had a pocket depth comparable to the active sites, but the connective attachment level did not change during each monitoring period. Subgingival plaque bacteria, and prostaglandin E₂ (PGE₂), interleukin-1 (IL-1), collagenase activity and lipopolysa ccharide (LPS) in GCF were compared at active sites with those at inactive sites.
In untreated periodontitis patients, PGE₂ in GCF and absolute counts of subgingival plaque bacteria were significantly higher at active sites. Interleukin-1α . ., IL-1β. active collagenase in GCF and the proportion of motile rods were elevated more often at active sites. In periodontitis patients on maintenance treatment, absolute counts of bacteria were significantly higher at active sites, and PGE₂ in GCF was elevated more often at such sites.
Linear discriminant analysis of data was shown to be useful for detecting active sites in untreated periodontitis, because no test could be used by itself for detection. The combination of PGE₂, IL-1 α, IL-1. β, LPS and collagenase level determinations, was most useful for detecting active sites, and the sensitivity and specificity for detection of active lesions was 62% and 100%, respectively. In contrast, the absolute counts of bacteria could be used by itself for detection of active sites in the periodontitis patients on maintenance treatment. Its sensitivity and specificity were both 82%.
In addition, the diagnostic method for detecting active sites obtained in untreated periodontitis patients was applied to another 19 patients with adult periodontitis. Periodontal disease sites of which the discriminant score (Z) was >0 responded less well to initial therapy than those in which Z was <0. In conclusion, the linear discriminant analysis could be one of the useful diagnostic methods for measurement of periodontal disease activity.

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Immunological mechanisms have been implicated in the pathogenesis and/or progression of human periodontal diseases. Therefore, recent studies have focused on the immunoregulatory mechanisms in periodontal diseases. T-cells have been recognized to play a central role in the immunoregulatory network at both local and systemic levels.
The autologous mixed lymphocyte reaction (AMLR), which is thought is thought to be a T-cell reaction involving recognition of HLA-DR antigen expressed on non-T-cells, has been suggested as a possible indicator of immunoregulation in autoimmune diseases such as systemic lupus erythematosus.
In the present study, AMLR in patients with adult periodontitis were evaluated. In addition phenotypic and functional characteristics of peripheral blood Tcells from patients showing low response in AMLR was investigated. The effect of periodontal therapy on AMLR was also examined.
T-cell and non-T-cell fractions were separated from peripheral blood of 80 patients with adult periodontitis using the method of E-rosette formation. The T-cell fraction was incubated with Mitomycin-C-pretreated non-T-cell fraction for 7 days at 37.. in a humidified 5% CO₂ atmosphere. The AMLR was expressed as the incorporation of ³H-thymidine for the previous 20 hours of culture (Δdpm).
Phenotypic analysis of both T-cells and non-T-cells was performed using flow cytometry by means of direct immunofluorescence technique using monoclonal antibodies against cell surface antigens including CD 4, CD 8, CD 36, HLA-DR, and CD 45 R. The functional analysis of T-cells was evaluated by IL-2 production in AMLR by means of bioassay using an IL-2-dependent T-cell line, CTLL-2.
AMLR responses in 80 periodontitis patients ranged from 51 to 59485 dpm (17607± 1428 dpm ; mean±SEM), while those of controls ranged from 13311 to 41636 dpm (24980±1332 dpm). Thirty-one of 80 adult periodontitis patients (39%) showed significantly lower responses in AMLR (<mean-2 SD of control group) than healthy subjects. No significant differences were observed in clinical parameters including probing depth, gingival index, alveolar bone loss and percentage of affected teeth between patients showing depressed AMLR (low-AMLR patients) and normal AMLR (normal-AMLR patients).
Phenotypic analysis of non-T-cell fractions revealed no significant differences in the percentages of monocytes and HLA-DR expressed B-cell. In contrast, the phenotypic analysis of T-cell fractions revealed that the percentage of CD 45R-positive cells in CD 4-positive cells (CD 4⁺CD 45R⁺cells) was significantly lower in low-AMLR patients than in normal-AMLR patients and healthy subjects. In addition, no signi-gcant differences were found in the percentages of CD 4-positive and CD 8-positive cells and the CD 4/CD 8 ratio between these three groups.
Interleukin-2 production in AMLR was significantly depressed only in low-AMLR patients. Depressed AMLR responses and low proportions of CD 4⁺CD 45R⁺ cells were recovered during conventional periodontal therapy.
These results indicate existence of a patient group showing low AMLR responses in clinically-diagnosed “adult periodontitis ” patients . It was also suggested that there could be phenotypic and functional disorders in peripheral blood T-cells in these patients, which might be closely related to the depression of AMLR. In addition, depressed AMLR responses in these low-AMLR patients might reflect changes in regulatory T-cell function induced by the state of periodontal disease.

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Neutrophils play an important role in the state of periodontal disease. The aims of this study are to examine the relationship between periodontal diseases and neutrophil functions, and to explain the pathogenesis of a periodontal disease associated with an anomaly of neutrophil cell surface glycoproteins.
Neutrophil functions including chemotaxis, phagocytosis and bactericidal activity were examined in 95 subjects. There were no significant differences between healthy subjects and patients, with regard to neutrophil functions. However, the patients with a disorder of chemotaxis were frequently detected as having early-onset periodontitis.
The levels of LFA-1 familyβ-subunits on the cell surfaces of neutrophils in 28 subjects (11 healthy subjects, 12 early-onset periodontitis patients and 5 later-onsetpariodontitis patients) were investigated by Western blotting and flow cytometry using the monoclonal antibody against the LFA-1 family . βsubunt. The levels of expression of the LFA-1 family . A-subunit on the cell surface membrane showed no significant differences in any subject. However, the stimulation of neutrophils using chemoattractant, N-formyl-methionyl-leucyl - phenylalanine, induced low levels of expression of the LFA-1 family . β-subunit in two patients, in contrast with that in the majority of subjects.
In conclusion, decreased expression of the LFA-1 family . β-subunit on the neutrophil cell surface may cause periodontal disease and the LFA-1 family . β-subunit is proposed as a unique, possible marker in a novel typing for a specific periodontal disease.

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The products of human leukocyte antigen (HLA) class II β-chain genes play an important role in the recognition of foreign antigens in immune reactions . The purpose of this study was to explore the possibility of gene diagnosis for periodontitis by the detection of variations in genes. Seventy Japanese patients with periodontitis and 26 healthy individuals were surveyed with respect to HLA phenotypic frequencies, however, no HLA phenotype specific to any type of periodontitis was observed . Therefore, in order to detect differences between some HLA phenotypes, restriction fragment length polymorphism (RFLP) analyses were undertaken with HLA-DR . β and HLA-DQ . β complementary DNA probes in 20 subjects (15 patients and 5 healthy individuals). The RFLP analysis of HLA-DQ . β gene digested with Bam HI revealed that genetic variation existed in only 4 patients with early-onset periodontitis. This genetic variation was also ascertained to be detectable by analysis using polymerase chain reaction PCR) method. Thus, these results substantiate the prospect that gene variations are useful as markers for novel gene diagnosis in periodontitis.

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The effects of 13 kinds of prostaglandins (PGs) on the activities of a human gingival fibroblast (ATCC CRL 1292) were widely examined . PGA₁ and PGD₂ caused deformation in morphology of the fibroblast, and all PGs tested showed inhibitory effects on proliferation, DNA synthesis, collagen synthesis, and noncollagenous protein synthesis in the fibroblast under the conditions used in this study, and many PGs tested increased the intracellular cyclic AMP (cAMP) level. Therefore, the mechanism by which PGE₂ inhibits DNA synthesis was examined in view of the increased cAMP level . The inhibitory effect of PGE₂ on DNA synthesis was not enhanced when the increase of intracellular cAMP level by PGE₂ was accelerated by a cAMP-phosphodiesterase inhibitor (IBMX). Further the inhibitory effect of PGE₂ on DNA synthesis was not weakened by inhibiting cAMP-dependent protein kinase (A-kinase).
It is suggested from the results that the inhibitory effect of PGE₂ on DNA synthesis in the fibroblast is not mediated through the cAMP.A-kinase system but probably through other cellular signalling systems.

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Glycosaminoglycans (GAG) in gingival crevicular fluid (GCF) were investigated using cellulose acetate electrophoresis of collected samples from mesial sites in the area from the most posterior molars to the incisors in 11 subjects with adult periodontitis .
Two kinds of hyaluronic acid which are different in migration in electrophoresis and dermatan sulfate were detected in GCF samples collected from untreated sites.
After effective antibacterial therapy, dermatan sulfate was not detected and the amount of slower migrating hyaluronic acid decreased significantly in GCF.
These findings suggest that GAG composition of GCF appears to reflect changes occurring in periodontal tissue during inflammation .

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In order to clarify the role of salivary proteins in formation of dental plaque, the state of aggregation among oral bacteria, and adsorption between oral bacteria and hydroxyapatite (HAp) in the fibronectin (FN) solution were evaluated by means of comparing turbidities and esticating zeta potential. Turbidity comparison analysis revealed that aggregation and adsorption of Streptococcus mutans were most strongly promoted, and those of Fusobacterium nucleatum were conversely inhibited by existence of FN.
Zeta potential measurement of oral bacteria and HAp showed that all samples (Bacteria and HAp) were electronegative. However, potentials approached neutral (±0) depending on FN concentrations, and results accommodated the Langmuir type for single molecular adsorption.
Although this investigation indicates that all samples combine with FN, this indication thus becomes inconsistent in comparison with data from the turbidity analysis.
This study concluded that this inconsistency was brought about by close or focal contact through RGD receptors or with the surface of bacterial cells.

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This study examined serotype distribution of Actinobacillus actinomycetemcomitans in the Japanese periodontal patients.
A total of 35 subjects were included in the study. They were between 16 to 56 years, and demonstrated at least the periodontal pockets with depth greater than 4 mm. Subgingival dental plaque was examined for the presence of Actinobacillus actinomycetemcomitans using previously descrived techniques. Briefly, supragingival dental plaque was removed by means of sterile cotton pledgets. Three sterile paper points were then inserted into the periodontal pocket untill resistance was met and left inplace for 30 seconds. Paper points from each sites were then pooled into tube containing 4.5ml of sterile prereduced Ringer's solution. Those were dispersed for 60 seconds and 0.1ml aliquotes were plated onto a selective medium TBSV) for isolation of Actinobacillus actinomycetemcomitans. After 48-72 hours of incubation at37.. in an anaerobic chambar (Gas-Pak System), the agar plate were examind for Actinobacillus actinomycetemcomitans. Colony morphology was observed directly on TSBV agar. All colony represented rough surface at primaly culture.
Using serotype specific rabbit antisera, oral isolates of Actinobacillus actinomycetemcomitans were assigned to one of three reported serotypes by means of Oucterlony agar-gel diffusion techuniques . The Ouchterlony agar-gel diffusion test was used with two different antigen preparations: sonic extract and autoclave extract. The agglutination test revealed that using autoclave extract of whole celles of Actinobacillus actinomycetemcomians was clearer than that of sonic extract. A total of 158 isolates of Actinobacillus actinomycetemcomitans from oral cavity of 25 subjects were serologically categolized. Sixteen sites exhibited serotype c, whereas 2 sites exhibited serotype a. Seventy three isolates of Actinobacillus actinomycetemcomitans from 14 sites were not serologically characterized. No isolates of Actinobacillus actinomycetemcomitans represented serotype b.
This study indicates that the high prevalence of serotype c in the subgingival plaque of Japanese periodontal patients compared to the much lower prevalence of serotype a and b.

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The effects of oral immunization on the colonization of Actinomyces viscosus (A. viscosus) were studied in two different experiments on rats. In the first experiment (Experiment 1), immunization with formalin-killed A. viscosus was carried out prior to inoculation with A. viscosus into the rat oral cavities. In the second experiment (Experiment 2), immunization with the same antigen as in Experiment 1 was performed after A. viscosus had been introduced into rat oral cavities.
Elevated anti-A. viscosus IgA and IgG antibody activities in saliva were observed in both experiments.
The inhibition of implantation of A. viscosus in rat oral cavities was clearly demonstrated in Experiment 1.
However, no exclusion of colonized A. viscosus from rat oral cavities was found in Experiment 2.
These results suggest that oral immunization with periodontopathic bacteria is effective for preventing the colonization of these bacteria. On the other hand, it is not effective for removing the already colonized bacteria from oral cavities.

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The purpose of this study was to investigate whether topical application of fluorides prevents bacterial invasion into the radicular dentinal tubules after root planing procedure. After removing the cementum of the periodontally healthy third molar with a sterile diamond bur, test samples were cut from the radicular dentin: 5. 5 mm in width and length. The surface of the samples was roughened with a waterproof sand paper (# 240), mached the surface after root planing. Each test sample was treated with 2% sodium fluoride solution (NaF), 2, 8% stannous fluoride solution (SnF₂) and a saline solution (control) for 4 minutes. Ten patients having a resin temporary bridge due to their missing mandibular first molars, were used in this study. Two pieces of the samples were embedded into the facial surface (brushing group) and the basal surface (nonbrushing group) of the pontic area with the embedded specimen's surface exposed to the oral cavity for 7 or 28 days. After each experimental period, histological sections were prepared stained with Gram's stain for the light microscopic observation.
The following results were obtained:
1. The bacterial penetration into the dentinal tubules was observed on both days 7 and 28, in nonbrushing and brushing groups.
2. The depth and percentage of bacterial invasion into the dentinal tubules of the 2-and 8%-SnF₂-treated groups were significantly less than the 2%-NaF-treated and control group.
3. The depth and the percentage of bacterial invasion into the dentinal tubules of the brushing group were significantly less than the non-brushing group.
4. The test samples on day 7 showed the lower values of depth and percentage of bacterial invasion into dentinal tubles than those of day 28 test samples.
This study suggested that 2- and 8%-SnF₂ application after root planing will considerably reduce the bacterial invasion into the dentinal tubules and their application with daily tooth brushing will greatly enhance the effectiveness to inhibit bacterial invasion.

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The purpose of this study was to compare the restrating of artificial bone defect after implantation of True bone ceramic (TBC) and Hydroxyapatite (HAP) in alveoral bone of adult beagel dogs. To be the experiment, periodontal osseous defects which 3 mm of length, 2 mm of width and 6 mm of depth from cement-enamel junction on the medial of P4 and M1 were created. Intrabony defects were grafted with TBC and HAP at P4 and Ml, respectively. Animals were sacrificed 1, 3 and 6 months after postoperatively. One month after implantation, the surface of TBC was surrounding by a connective tissue and its pore site was filled with a connective tissue and vascular elements. Regeneration of alveolar bone occurred at the base and lateral of the bone defect cavity. However, its regeneration has shown no direct contact was observed between the newly formed bone and the implant material. At 3 months after implantation, bone regeneration was appered the central area of defect and new bone formation was a lamellar bony structure in contact with the TBC. Furthermore, the TBC was directly contacted with a newly formed bone, bone formation appeared far from original bone at 6 months.
On the other hand, regeneration of alveolar bone in HAP specium occurred at the base and lateral wall of bone cavity. The HAP was surrounding by a connective tissue at one month after. 3 months after implantation, the HAP graft was surrounded with newely formed bone. But, almost granular HAP was cupsulated with fibrous tissue and direct contact was not observed between new bone and the implant material. At 6 months, bounndaris between the HAP and new formed bone were indistinct and fine fibers invaded into granule of the HAP.

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The purpose of this study was to investigate the effects of porous hydroxyapatite combined with fresh autogenous bone.
Part 1:
Two months after extracting P₃ and P₄ from the adult dog mandible, bony defects were produced in the mandible. Into each defect, hydroxyapatite combined with bone (the ratio of fresh autogenous bone to porous hydroxyapatite ; 1: 1, 3: 1, 6: 1) and hydroxyapatite alone were implanted. Dogs were sacrificed after 3, 6 and 12 weeks. The examination of obtained tissue specimens indicated that hydroxyapatite combind with bone (at a ratio of 3: 1) was more suitable than others as an implant material because it promoted tight bony fixation.
Part. 2:
Three-walled osseous defects with plaque-affected roots were prepared and filled with fresh autogenous bone, hydroxyapatite and hydroxyapatite combined with bone (at a ratio of 3: 1) during a period of 1, 2, 3, 4 and 8 weeks. As a control, defects were treated with flap surgery without filling with implant material.
Histomatric comparison of sections of hydroxyapatite combined with bone (at a 3: 1 ratio) showed that a periodontal ligament existed between the root and alveolar bone containing hydroxyapatite. Newly-formed cementum was seen on the root surface.
As seen above, hydroxyapatite combined with bone (at a 3: 1 ratio) showed good affinity with bony tissue and can be advantageous as bone graft material in periodontal therapy.

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The aim of this study was to detect clinical signs and bacterial presence using povidone iodine solution PVP-I) irrigated into periodontal pockets.
The 16 patients (with probingdepths. 4mm) were selected at random and classified into two groups . The test groups were PVP-I administration and distilled water (DW) administration groups and a no-irrigation group served as a control . Improvement of the clinical syndrome was significantly observed in the gingival crevicular fluid (GCF) and bleeding index.
In terms of detected micro-organisms, in the test groups cocci were found to be increased, whereas a slight decrease in motile rods was noted.
With respect to changes in micro-organism population, B. gingivalis, B. intermedius and A. actinomycetemcomitans were observed to be on the decrease or to be disappearing.
We conclude that PVP-I irrigation into the pocket gave effective results compared with the DW and noirrigation control groups.

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The purpose of this study was to produce an experimental model of traumatic occlusion in Rhesus monkeys and to characterize the changes in periodontal tissues clinically and histopathologically.
Nine Rhesus monkeys were used. Four weeks after beginning the oral hygiene program, all 4 canines were cut away from the gingival margin. Immediately after this, all the monkeys showed distinct signs of bruxism (grinding). At week 0 cast restorations designed to fill the “free entry” without disturbing the intercuspal occlusal position, were set at the 2 nd maxillary premolars (experimental teeth). Thereafter only the experimental teeth were in contact with the occluding teeth during lateral movement caused by bruxism.
The results were as follows:
1) Mobility of the experimental teeth increased markedly during the first 6 weeks but showed no increase thereafter.
2) Histological specimens of experimental teeth showed that destructive changes in tissues were seen during the first 4 weeks and repairable changes in tissues were seen after week 8.
3) Mobility of the experimental teeth in animals, in which restorations of the experimental teeth were removed and canines reinstalled in their original position, markedly decreased.
4) New bone formation was seen on the side of the periodontal ligament on experimental teeth in animals in which restorations of the experimental teeth were removed and canines reinstalled in their original position.
It was concluded that trauma from occlosion in monkeys was produced at the 2 nd maxillary premolars by the experimental procedures, and was comparable to that observed in humans. The tissue changes caused by trauma from occlusion were reversible and no pocket formation was apparent under conditions of intensive plaque control .

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Sixteen cases (males and females from the age 27 to 62), in which the premature contact in the intercuspal position was considerd one of the causes for the alveolar bone loss, were observed in order to investigate the relationship between the shape of the alveolar bone loss and the occlusal contact. With the image analyzer, we observed the pattern of the alveolar bone loss or the position of the premature contact in the intercuspal position, the occlusal position and it's area.
The results were as follows:
1. There was a tendency that the premature contact area was of ten observed on the side of alveolar bone loss for the Type I (Type I; the bone loss observed on the mesial or distal interalveolar septum), and on the outer inclines of the buccal cusp for the Type II (Type II ; the bone loss on the mesial and distal interalveolar septum) and Type III (Type M; the bone loss on the interradicular septum).
2. There was a tendency that Occlusal Contact Area (OCA) area and Luminosity Grade 1 (LG 1) area were of wide distribution on the side of alveolar bone loss for Type I; on the outer inclines of the buccal cusp, the inner inclins of the buccal cusp, the inner inclines of the lingual cusp, and the distal marginal ledge for Type II; on the outer inclines of the buccal cusp, the inner inclines of the buccal cusp, the inner inclines of the lingual cusp for Type III.
3. As for the distribution of OCA area and LG 1 area on the outer and inner inclines, a wider distribution was observed on the outer inclines than on the inner inclines for Type I and II. For Type III, a wider distribution was recognized on the inner inclines.

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Choosing five adult men (control) and five periodontal patients who have all their teeth, we researched the change of occlusal condition with the quantitative lateral movement by used of “Superposed rubber pattern method ”. Measurements was carried out in four different areas that is divided by the interocclusal distance.
The results are as follows:
1. The tendency of the changes of occlusal contact area by the quantitative lateral movement.
1) Both the adult men and the periodontal patients indicated the tendency of remarkably decreasing in under 0.5mm area and the tendency of decreasing in from 0.5mm to 1.0mm area.
2) Both the adult men and the periodontal patients indicated the tendency of increasing in from 1.0mm to 2.0mm area and the tendency of suddenly increasing of over 2.0mm area.
2. Distinctive areas in each of the four different areas were under 0.5mm area and from 1.0mm to 2.0 mm area. As for the periodontal patients, this is due to decreasing in from 1.0mm to 2.0mm area with an increase in area of under 0.5mm. This thing indicats that the leveling molar's occlusal surfaces by attrition with sliding of maxillo-mandibular occlusal surface are shown by the periodontal patients remarkably.

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The purpose of this study was to develop an ELISA assay to chondroitin sulfate isomers (C4S, C6S and DS) proteoglycan in GCF associated with experimentally-induced periodontitis in dogs. Combination of these antibodies (9-A-2 and 3-B-3) and specific enzymatic digestion have made possible the identification of C4S, C6S and DS. Experimental periodontitis was induced by silk ligature placement below the gingival margin of the canine mandibular molars. GCF was collected in microcapillary tubes at 0, 3, 7, 21 and 60 days after ligature in three mongrel dogs. Samples were diluted 5. 10 in 0.15M PBS pH 7. 2. Indirect ELISA was performed. Standard curve and detection level of GAG-PG had been examined in a preliminary study using bovine nasal cartilage proteoglycan monomer. The quantity of C4S, C6S and DS, though fluctuating, increased in proportion with the severity of inflammation. In particular, C4S was increased in the acute phase and then decreased gradually. The present study has confirmed that ELISA assay enables the detection of GAGs in GCF associated with experimentally-induced periodontitis in the dog.

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This study describes the regenerating process of long junctional epithelium (LJE) to the denuded root cementum. The materials were premolars of mongrel dogs. After mucoperiosteal flaps were raised, the roots were exposed artificially by removing buccal cortical bone. The denuded root surfaces were treated with sodium hypochlorite solution. The root surfaces were then categorized into a group (L) with topical application of laminin (1mg/ml, E-Y Laboratories Co., U. S. A.) and a group (N) with non-topical administration of laminin. The exposed bone surfaces were covered by a polycarbonate membrane (pore size 3. μm, Nuclepore Co., U. S. A.). Flaps were repositioned and sutured. Animals were sacrificed 2, 4, 8 weeks after surgery and tissues histopathologically examined.
1. The regenerative junctional epithelium (RJE) in N group showed apical proliferation along the root surface at 4 weeks but was reduced in length at 8 weeks.
2. The RJE in L group also proliferated apically and reached the apical two-thirds of the denuded root surface at 4 weeks, remaining at this level until 8 weeks.
3. Histometrically, the length of the RJE in L group was greater than that in N group.

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The present investigation was designed to evaluate periodontal wound healing following implantation with 5 different cross-linked types of atelocollagen membrane. Fourteen mongrel adult dogs were used. After elevating a partial thickness flap following semilunar incision on the buccal aspect of I₂, P₁, P₃, P₄, M₁ of the maxilla and mandible on the right side, and elevating a full thickness flap at the same sites on the left side, 5 different cross-linked types of atelocollagen membrane were implanted. The dogs were sacrificed to provide observation periods of 1, 3, 5, 7, 14, 21, 28d. after implantation of membranes. Wound healing processes were examined by histopathological observation with regards the timing of membrane absorption and inflammatory reaction.
The results demonstrated that the timing of membrane's absorption was prolonged according to the degree of cross-linking. Among the different crosslinked types of atelocollagen membrane, the degree of inflammatory response with the passage of time was less recognized. In addition, highly cross-linked atelocollagen membranes (Col. . 5, Col. . 10) remained in the body at 28d. after implantation. Especially, the architecture of the tissue infiltrating the remnants of the atelocollagen membranes was different between, in implantation under the partial thickness flap and in implantation under the full thickness flap.

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The purpose of this study was to investigate whether topical application of fluorides prevents plaque formation on radicular dentin after root planing procedures. After removing the cementum of periodontally-healthy third molars with a sterile diamond bur, test samples (5. 5mm) were cut from radicular dentin. The surface of the samples was roughened with waterproof sand paper (#240) to match the surface after root planing. Each test sample was treated with 2% sodium fluoride solution (NaF), 2% and 8% stannous fluoride solution (SnF₂) and a saline solution (control) for 4 minutes. Ten patients having a resin temporary bridge due to missing mandibular first molars, were used in this study . Two pieces of sample were embedded into the facial surface (brushing group) and the basal surface (nonbrushing group) of the pontic area with the embedded specimen's surface exposed in the oral cavity for 7 or 28 days. After each experimental period, histological sections were prepared and stained with Gram's stain for light microscopy.
The following results were obtained.
1. The 2% and 8% SnF₂ treated groups showed greater reduction of plaque formation than the control group on day 7 in the non-brushing group.
2. The amount of plaque formation on days 7 and 28 in the brushing group was no less than that in the control group.
3. The amount of plaque formation on radicular dentin in the brushing group was significantly less than that in the non-brushing group.
4. This study suggested that 2% and 8% SnF₂ applications after root planing will reduce plaque formation on radicular dentin.

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Action of the oral mucosa-dressing “Softach ® A” on the wound healing process of rat palatal mucosa was investigated based on the histological and histometrical evaluation for the purpose to explain the clinical effectiveness of this material on the healing of mucosal defects as in traumatic injury and aphthous stomatitis.
In the experimental group, the dressing was applied immediately after making the wound and left for 8 hours under anesthesia and detached spontaneously after awaking. The dressing material was firmly attached to the wound surface, at least, for 8 hours.
Histometrically it was indicated that both the extension of regenerated oral epithelium and the reestablishment of keratinized squamous epithelium were more significantly promoted at 72 hours after wound formation in the experimental group than in the control group. From histological findings it was also shown that the fibrin matrix was more substantially preserved at 8 hours after surgery under the dressing compared with the open wound.
The present results would suggest that the application of Softach ® A to the oral wound is effective to accelerate the epithelial regeneration by maintaining an adequate environment for the wound probably due to blockage of external irritation such as bacterial infection.

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Seven species (Bacteroides gingivalis, Bacteroides intermedius, Bacteroides rnelaninogenicus, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Capnocytophaga sp, Eikenella corrodens) as periodontal pathogenetic bacteria and two control species (Streptococcus intermedius, Pseudomonas aeruginosa) were selected in order to study the bactericidal effects of 10% povidone-iodine solution (PVP-I) in vitro.
Povidone-iodine was diluted 100. , 400. , 800. , 1, 600. , 3, 200. , 6, 400. and 12, 800. and contact times were 15 sec, 30 sec and 60sec.
Strongest bactericidal effects on the seven periodontal pathogenic bacteria and two control bacteria were seen at a dilution of 400. and contact time of 15sec.
Based on these findings, we advocate 0.25% PVP-I for oral mucosa and periontal pocket irrigation .

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Elevated serum IgG antibody titers against several periodontopathic bacteria in periodontitis patients have been reported. The purpose of this study was to investigate the effects of aging on serum IgG titers against these bacteria.
Serum IgG titers against 7 periodontopathic bacteria were measured in eleven subjects in their 20's, ten in their 40's, six in their 50's and six in their 60's, all with healthy periodontal tissues, by ELISA method.
Concerning the result of titers against B. gingivalis, B. loescheii, E. corrodens and F. nucleatum, there were no significant differences between the four age groups. However titers in subjects in their 20's, against A. actinomycetemcomitans, B. intermedius and C. ochracea were higher than those in other generations. This suggests that aging has little effect on the elevation of antibody titers against some periodontopathic bacteria in periodontitis patients, and that such serum antibody titers in patients seem to reflect the periodontal status.

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A variety of clinical parameters are now used in diagnostic examination for periodontal disease. Some reports, however, have pointed out that the parameters used contain several problems concerning reproducibility and objectivity. The purpose of the present study was to determine the degree of correlation between parameters. The subjects were 27 first visit patients with adult periodontitis (16 women and 11 men), whose mean age was 45.1 years with a range of 18-62 years. One hundred forty-seven different sites with radiographic evidence of alveolar bone loss were randomly selected. The clinical parameters used in this study were Plaque Index (PH), GCF volume, probing depth (PD), attachment level (AL), Gingival Index (GI) and tooth mobility (Mo). All measurements were made by one of the authors.
The results obtained were as follows:
1. The relationships between the clinical parameters were all statistically significant at P< 0.01. The correlation coefficients were, for example, 0.69 between GCF volume and PD, 0.53 between GCF volume and AL, 0.57 between PD and GI, and 0.60 between AL and Mo, respectively.
2. The sites examined were classified into 2 groups which were an effective oral hygiene group (P1I=0 or 1) and a poor oral hygiene group (P1I = 2 or 3) according to the extent of plaque accumulation. In the effective oral hygiene group GCF volume correlated more with such parameters as PD, AL and GI than those in the poor oral hygiene group.
3. The effect of supragingival plaque on GCF volume according to the probing depth was examined. It was consequently found that if under 5 mm, the PD had a positive relationship with GCF volume and an evident influence on it.

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In the present study, the effect of supragingival plaque control and subgingival water irrigation on subgingival microflora and clinical parameters was investigated in periodontal pockets. Nine adult periodontal patients participated in this study. In each patient, diseased sites (probing depth approximately 5.0mm) were investigated microbiologically by phase contrast microscopy for determination of spirochete number and total bacterial counts. Plaqueindex (PI-I), gingival-index (GI), and probing pocket depth were used as clinical parameters. Clinical and microbiological data was recorded at 0, 2 and 4 weeks.
Supragingival plaque control included brushing by scrub method and interdental cleaning with an interdental brush and flossing. The test sites were irrigated with water twice every week for 4 weeks by Perio-Pik ®. The sites with no presence of supragingival plaque at 4 weeks and irrigation sites showed marked beneficial clinical changes at the end of the 4 weeks with decreased total bacterial counts and spirochete counts to less than baseline value.
It was shown that direct water jet irrigation has a flushing effect on subgingival microflora. It was concluded that frequently water irrigation practiced as part of the supragingival plaque control program in moderate periodontal pockets has a beneficial effect on subgingival bacterial flora and clinical parameters.

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The effects of ultrasonic scaling in combination with povidone-iodine solution were examined bacteriologically.
The results obtained were as follows:
1. In phase contrast microscopy, both total bacterial count and spirochetal and motile rod incidence decreased rapidly 3 days after instrumentation, thereafter remaining at about the same level in each group. Both total bacteria and spirochetal and motile rod incidence decreased after ultrasonic scaling in combination with povidone-iodine solution in comparison with ultrasonic scaling alone and root planing.
2. Total bacterial count and proportional distribution of black-pigmented Bacteroides in periodontal pockets decreased weekly after instrumentation in each group. Total bacterial count and proportionaldistribution of black-pigmented Bacteroides decreased after ultrasonic scaling in combination with povidoneiodine solution in comparison with ultrasonic scaling alone and root planing.

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The prevalence of periodontal disease in handicapped persons in Nagasaki Prefecture was investigated with the purpose of establishing a system for dental care and prevention and treatment of periodontal disease for such group of persons.
The subjects were 144 handicapped persons (resident at home or in an institute), aged 17 to 68 years (average: 31.4 yrs). Clinical parameters examined were plaque index (PII), gingival index (GI), calculus index (CI) and probing pocket depth (PPD) at mesio-buccal sites at six representive teeth (6 14 41 6)
The results were as follows:
1. Approximately 99% of the subjects had periodontal disease (58% had periodontitis and 41% had gingivitis). Especially in young adults, the prevalence of periodontitis was high (group of 17.19 year olds: 22%; group of 20.29 year olds: 43%).
2. The mean values of PPD, GI, P1I, CI were higher than in healthy persons. In terms of prevalence of periodontitis and periodontal conditions, there were significant differences between the higher IQ (intelligence quotient) group (IQ. 36) and the lower IQ group (IQ35), in both persons resident at home or an institute.
3. Approximately 76% of subjects had more than one deep periodontal pocket (PPD. +4mm).
4. Approximately 31% of subjects administered antiepileptics had gingival hyperplasia, and the majority of those subjects were found to have misalignment of the teeth and malocclusion.

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