In order to elucidate the alteration of polymorphonuclear leukocytes (PMNs) that exude into inflamed areas in periodontal disease, we prepared peritoneal exudate PMNs by intraperitoneally (i. p.) injecting casein into mice and examined the ability of these cells to produce superoxide anion and to express C 3 bi receptors.
Following intraperitoneal injection of casein, the number of peritoneally exuded cells was markedly increased at 3 hr and was the greatest at 9 hr. At 3 and 9 hrs after the onset of inflammation, percentages of PMNs in total exudate cells were 85% and over 95%, respectively, whereas macrophages and lymphocytes were exuded in the lowest of amounts.
Phorbol myristate acetate (PMA) and supernatant extracts of two species of bacteria, P. gingivalis and F. nucleatum, induced 0₂^- production by peritoneally exuded PMNs. Moreover, their ability to produce O₂^- changed depending upon the time after the onset of PMNs exuded at 6 and 9 hrs. On the other hand, formyl-methionyl-leucylphenylalanine (FMLP) did not increase O₂^- production.
Lipopolysaccharide from E. coli (E-LPS), by itself, did not increase O₂^- production by PMNs, but it did enhance the stimulating effect of PMA on 0₂^-production and increased the production in combination with FMLP (priming effect).
According to the results of fluorescence-activated cell sorter (FACS) analysis, peritoneal exudate cells following intraperitoneal injection of casein were classified into at least two groups, one expressing the C3 bi receptor weakly (weakly positive cells) and the other, expressing the same receptor strongly (strongly positive cells). The former cells constituted 55-65% of the total exudate cells, while the latter cells accounted for only, 10-20%.
The expression levels of C3 bi receptor in weakly positive cells, exuded 3 and 6 hrs after the onset of inflammation, were almost the same as the levelof blood PMNs. However, the receptor level was greatly increased in cells exuded 9 hr after inflammation. Stimulation with phorbol myristate acetate PMA, (0.5 μg/ml) and FMLP (10^-8 M) significantly elevated the expression level of C3 bi receptors in cells exuded 3-9 hrs after the start of inflammation. However, FMLP (10^-6 M) and E-LPS (0.2 μg/ml) decreased the level of these reports in cells exuded 9 hr after the casein injection. The proportion of weakly positive cells to total cells increased during the progression of inflammation.
Compared with that of blood PMNs, the expression level of the C3 bi receptor in strongly positive cells was already maximal at 3 hr after the onset of inflammation, and did not change during the progression of inflammation (at least through 9 hr). Stimulation with PMA, FMLP, and E-LPS did not change the expression level of the C3 bi receptor in these cells. The total percentage of cells strongly positive decreased from 6 hr after the injection of 2% casein.
The results of the present study suggest that mouse PMNs induced by casein injection and exuded into the peritoneal cavity are heterogeneous on the basis of their ability to produce O₂^- and to express C3 bi receptors. These observations suggest that there are different cell populations among PMNs induced upon onset of inflammation.

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This study describes the distribution of tenascin in periodintal tissue of rats after flap operation. Experimental flap operations were performed on the palatal gingiva of Wistar rats. The specimens were examined by indirect immunofluorescence for the presence of tenascin. In normal periodontal tissue, tenascin is detected in the connective tissue beneath the epithelium, on the periosteal of alveolar bone and in the periodontal ligament close to the cementum and alveolar bone. At 3 days after surgery, tenascin staining was intense in the connective tissue beneath the epithelium slightly distal from the utmost tip of migrating epithelium. During the period of 5-7 days after surgery, tenascin was abundant in granulation tissue. In granulation tissue, the deposition peak of tenascin was on the 5 th post-operative day, and then decreased gradually. These results suggest that tenascin influences cell differentiation and proliferation because it appears at sites of high cell activity.

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The purpose of the present study was to observe the formation of dento-epithelial attachment apparatus in vitro, and to demonstrate the detailed morphology of these structures.
Epithelial and fibroblast-like cells were individually isolated from gingiva and periodotal ligament of adult rabbits. For cell culture, the double chamber method was used. Collagen gel containing fibroblast-like cells were embedded into the inner chamber. The lower part of the root segments were implanted in collagen gel, and epithelial cells were seeded on cllagen gel surface.
After 3 days culture, the growth medium was removed from the inner chamber and only the epithelial cell layer was exposed to air. After 7 more days, the cultured epithelium was compared to the oral epithelium of adult rabbit with light and electron microscopy.
As a result of this model, surface layer of epithelium was keratinized upon exposure to air. Epithelial cells were observed to be attached by hemidesmosomes to root surfaces. A restrained downgrowth of the epithelial cells was observed in collagen gel along the root surface. Epithelium in this new developed three dimensional culture model using collagen gel may be similar to the oral epithelium in vivo. This model makes it possible to explore the effect of specific factors on dento-epithelial interactions.

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An investigation was conducted to determine the bactericidal effects of He-Ne laser irradiation on Streptococcus mutans PS 14 (S. mutans). Our previous study had shown that bactericidal effects on S. mutans were produced only in the presence of dyes which were contained in Mitis Salivarius (MS) agar medium.
In this study, these dyes (crystal violet and trypan blue) were added respectively to Brain Heart Infusion (BHI) agar mudium, soft agar and hard agar at various concentrations. A He-Ne laser (Acusoft, Osada Electric Co., Tokyo, Japan) was used, and operated at a power output of 10 mW. Bactericidal effects were determined by the formation of a growth inhibition zone on the agar plates. The laser irradiation was done 0.5 cm distant from the surface of a 15 ml BHI agar plate containing the above dyes. The S. mutans strain was cultured overnight in BHI broth. After irradiation, 2.5ml of soft agar containing 0.5 ml of the above bacterial suspension was poured on the agar plates, and then the plates were incubated aerobically at 37.. for 24 h.
As growth inhibition was not observed under the above conditions, the bactericidal effect did not remain for only a short time after laser irradiation. In the other experiment coupled with BHI agar, soft agar and hard agar (each of which contained crystal violet or trypan blue), the bactericidal effects were clearly observed under all of the experimental conditions when crystal violet was used, but not in the presence of trypan blue.
These results suggest that the bactericidal effect of He-Ne laser irradiation might be related to excitation of the crystal violet molecule, and that the photodynamic effect of the dye kills the S. mutans cells.

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Recently, the biological effects of low power laser irradiation have been studied. Previous studies have demonstrated that He-Ne laser irradiation facilitates bone regeneration and promotes wound healing. Although the therapeutic effect of laser on bone is well established, few in vitro studies have analyzed the effects of low power laser. The present study was conducted to investigate the effects of He-Ne laser irradiation on human alveolar bone -derived cells .
A continuous wave 632.8 nm He-Ne laser Acusoft, Osada Electric Co., Tokyo, Japan) w ith a power output of 10 mW was used. The cultured cells were obtained from human alveolar bone fragments, after the fragments had been treated with bacteriase collagenase. This cell population possessed properties of osteoblastic cells. The cells were irradiated with the He-Ne laser using the following 4 different energy densities and time combination; no irradiation (control), 0.1 J/cm² (1, 2 or 3 irradiation periods), 1.0 J/cm² (1, 2 or 3 irradiation periods), 10.0 J/cm² (1, 2 or 3 irradiation periods).
Cell proliferation, alkaline phosphatase (ALP_ase) activity and mineralized nodule formation were determined after the laser irradiation. The number of cells was counted daily, on days 1-15, using a Hoechst 33342. ALP_ase activity of the cells was determined on culture days 8, 10, 12, 14 and 16 after seeding. Mineralized nodule formation was assessed on culture day 30 after seeding by staining with alizaline red S. A microprobe connected to a degital-thermometer was used to monitor the temperature of the medium during irradiation.
Results.
1. The cell growth rate was higher in the laser irradiation groups than in the control group in the inintial phase of cell proliferation.
2. The peak of ALP_ase activity appeared earlier in the laser irradiation groups than in the control group.
3. Nodule formation in the laser irradiation groups, as demonstrated by alizalin red S staining, was more pronounced than in the control group.
4. No elevation of temperature was noted during laser exposure.
The results suggest that He-Ne laser irradiation faciliations facilitates bone regeneration.

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Idiotype (Id) -anti-Id interaction has been shown to be an important immunoregulatory mechanism. It is, therefore, plausible that the antibody response to Porphyromonas gingivalis, which is commonly found in periodontitis patients, is also controlled by the Id network. However, to our knowledge, there have been no reports concerning the Id-anti-Id interaction in this disease. The purpose of this study was to demonstrate anti-Id antibody (Ab 2) directed against the anti-P. gingivalis antibody (Ab 1) in human sera.
Several monoclonal antibodies (MoAb) were prepared in BALB/c mice immunized with crude P. gingivalis antigen. One of the MoAb, termed PF 18, recognized an epitope of the saccharide moiety on the cell surface of the organism, and competed with Abl in sera derived from all 10 patients examined.
The Fab fragment from PF 18 was utilized as a substitute for the idiotype of the human Ab 1 in the following experiments. Anti-PF 18 Id (Ab 2) activity was detected by ELISA in 9/10 patients only after absorption of sera with immobilized P. gingivalis. However, this activity was not demonstrated in control sera from healthy subjects. The results suggest that the Ab 1 and the Ab 2 associated with each other and formed soluble immune complexes in the sera of patients.
Affinity purified antigen preparation by PF 18-MoAb from a sonic extract of P. gingivalis was capable of inhibiting the Ab 2 anti-Id activity in human sera. Monoclonal anti-PF 18-Id antibody (APF 1) was established in a syngenic BALB/c mouse. Both APF 1 and PF 18 itself blocked the human Ab 2 activity, but not the other MoAbs directed against P. gingivalis. These results suggest that the human Ab 2 reacted with the paratope of PF 18. The PF 18-Id bearing Ab 1 was detected by binding of APF 1 in the 9 patients exhibiting the Ab 2 activity, and 2/10 control subjects.
Production of anti-PF 18-Id Ab 2 was confirmed in mice injected with P. gingivalis. This Ab 2 was also detectable in sera after absorption with immobilized antigen as well as human Ab 2. The Ab 2 activity was rather quickly elevated, within 2 days after the booster injection, as compared with the anti-P. gingivalis Ab 1 activity, which reached a maximum at 16 days after the booster. This cyclic response may reflect a promoting role of the anti-Id antibody in the anti-P. gingivalis response.
Taken together, the results of this study suggest that the idiotype network regulatory mechanism may play an important role in the immune responses of human adult periodontitis. The presence of and -Id antibody seems to be closely related to the existence of the disease.

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Increasing clinical usage and application of biomaterials in tissue substitution have led to the development of a new periodontal therapy and explores the biology involved in the integration of implant materials into the surrounding bone tissue. In periodontics, the process of integration is considered to be of pivotal importance for establishing an intimate and stable connection between bone and the implant surface. In this study, MG 63 from an osteoblastic cell line derived from human osteosarcoma were cultured with or without hydroxyapatite (HAP). Examinations for morphology, biosynthesis of extracellular matrix (fibronectin, type I and type III collagen) and osteocalcin synthesis as a function of mineralization during culture times of 1 to 4 weeks, were conducted. The nature of the contact sites formed during the adhesion of osteoblasts to HAP was investigated by fluorescence microscopy and adapted the ACAS 570, laser cytometer for measuring average fluorescence on individual specimes. Fluorescence microscopy and the laser cytometer revealed that osteoblasts adhere securely to the HAP surface. The fibronectin caused the osteoblasts to adhere securely to the HAP surface were observed during 1 week of adhesion. On both type I and III collagen, the cells became round after secretion of fibronectin during the next 3 to 4 weeks. In addition, the synthesis of extracellular matrix and secretion of osteocalcin, subsequent to mineralization, were both substantially enhanced in cultures both with or without HAP. The R-G-D patterns observed during collagen and fibronectin synthesis may be evidence of the formation of extracelluar matrix contents.
These results strongly suggest that HAP surfaces may act as a substratum to permiting cell ingrowth and thereby improving bone formation at clinical bone defects.

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The purpose of the present study was to investigate histologically and histometrically the effect of fluoride on the experimental periodontal lesion in rats.
Ninety rats were used in this study. The animals were divided equally into Group A, B, C, D, E, and F. Group A and B received no fluoride administration. Group C and D received 1 mg/kg of daily fluoride oral administration. Group E and F received 5 mg/kg of daily fluoride oral administration. In all animals, suturing nylon threads were inserted between the maxillary 1 st and 2 nd molars for 3 weeks to produce slight inflammation of the gingival tissues. Then, the animals of Group A, C, and E received no injection of methotrexate, whereas Group B, D, and F were injected with 7.5 mg/kg of methotrexate once a day for 3 days. The animals were killed at 5, 7, and 9 days after the last injection or no injection of methotrexate. During the sacrifice, peripheral blood was taken from all animals. White blood cells and neutrophils were counted and the periodontal tissues were examined by light microscopy. The alveolar bones of the animals from the experimental period of 7 days in Group A, B, E, and F were further examined by the fluoride electrode method.
1. Blood findings
In Group A, C, and E, the white blood cell (WBC) count and neutrophil count (NC) did not show any changes. In Group B, D, and F, however, WBC and NC decreased at 5 and 7 days.
2. Histrogical findings
In Group A, C, and E, the animals did not show any changes except for a slight inflammatory cell infiltration of the gingival connective tissue. In Group B and D, the animals exhibited remarkable resoption of the alveolar bone at 7 and 9 days. In Group F, the animals showed slight resorption of the alveolar bone at 7 and 9 days.
3. Histometrical findings
In Group A, C, and E, the animals did not show any changes in alveolar bone loss. In Group B, D, and F, the animals showed increased alveolar bone loss at 7 and 9 days. In Group F, however, the alveolar bone loss at 7 and 9 weeks was significantly slighter (P<0.01) than that in Group B and D for the same days.
4. Findings by the fluoride electrode method
In Group E and F, the alveolar bone showed increased fluoride concentration when compared with that of the alveolar bone of Group A and B. In Group E, it exhibited significant increase (P<0.05).
The results of the present study indicated that a proper dose of fluoride administration may reduce the severe periodontal lesion induced by local and systemic factors in rats.

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Cilia may be organisms that are involved in such a modification process since single cilium has been reported presence in various organs and tissues. It also appears that even a single cilium has a sensory or chemoreceptive function which supplements that of the epithelial cells. Used for this study were the upper first molars of 28 Wistar rats. In a control group that was also observed, physiological saline was topically applied to the palatal sulci, whereas in the studied group, prior to the removal of the molars, bacterial protease was applied in the same method. The animals were treated once a day for 1, 3 and 5 days. Differences in the distribution and structure of single cilium in healthy junctional epithelium (JE) and in inflamed JE have been examined using an electron microscope. In the control group, single cilia were observed in the JE cells of all layers. At 1 day in the treated group, only in the cells of the basal layer, cilia were found. In the same group at 3 and 5 day, no cilium was present in the cells of all JE layers. From the above observations, it would appear that each cilium has a sensory or chemoreceptive function. It can be speculated that single cilia may play an important role in the inflammatory response.

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Depth of periodontal pockets was recorded using eight standard measurements (distal, distofacial, facial, mesiofacial, mesial, distoligual, lingual and mesiolingual) and investigated at the time of flap surgery, and 6 and 12 months postoperatively. A total of 3080 surfaces of 385 teeth from 143 cases was studied at flap surgery, and 40 cases at 6 months and 50 cases at 12 months after operation. Depth of periodontal pockets at flap surgery was 3.8±2.0mm and deeper pockets remained in the maxillary and molar areas. Depth of periodontal pockets at 6 months was 2.0mm±1.0mm, half of that at flap surgery. Depth of periodontal pockets was improved 1.9±1.7mm and 82.6% improved by more than 1mm. Depth of periodontal pockets at 12 months after operation was 2.2±1.1mm, deeper than at 6 months. Depth of periodontal pockets was improved 1.5±1.9mm and 68.2% improved by more than 1mm. Depth of periodontal pockets at 12 months after operation had a tendency of recur. Depth of periodontal pockets on the apically positioned flap improved more than that of the modified widman flap, both 6 and 12 months after operation.

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Periodontal pocket irrigation with Acess® A solution was performed on patients with periodontal disease, then changes in clinical parameters and bacterial flora were evaluated in comparison to those of patients undergoing irrigation with sterile distilled water. As results, clinical findings were significantly better for all parameters, except plaque index, in the group treated with Acess® A solution than in the group treated with sterile distilled water. Observation of changes in bacterial flora revealed that both the rate of decrease in total bacterial counts and the decrease in the proportion of motile rods among all bacteria were greater in the Acess® A group than in the sterile distilled water group. No adverse effects were observed in either group. These findings indicate that periodontal pocket irrigation with Acess® A solution may provide a useful therapy for periodontal disease.

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The status of periodontal patients on initial examination performed from June 1990 to February 1992, was evaluated and compared with the results of five years previously.
In this study, a questionnaire for periodontal patients at the initial visit and the condition of plaque accumulation were investigated. The Questionnaire consisted of (1) chief complaint, (2) habits and favorite food, (3) experience of periodontal treatment, (4) conception of oral hygiene, (5) demand for treatment.
Patients 41. `50 years old were the majority and the previously stage of their disease increased in comparison with five years previously. The average percentage of plaque control recored (P.C.R.) at the initial visit was 61.1% and the percentage of P.C.R. increased with age.
As to the chief complaint, tooth mobility was predominant and patients who had the symptoms of masticatory disturbance and tooth malalignment showed higher percentages of P.C.R. than others. The number of patients who experienced periodontal treatment was higher percentage than that of five years previously.
As brushing times per day increased and as the toothbrush-exchange period shortened, their P.C.R. became lower.
In general, the conception of oral hygiene had become instilled in people's daily living in comparison with five years previously.

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A study was conducted to examine the mechanism of the bactericidal effect of He-Ne laser irradiation on Streptococcus mutans, and to clarify the conditions under which the bactericidal effect was expressed.
Two milliliters of 0.5% agar plus 0.5 ml of bacterial cell suspension containing crystal violet (CV) were poured onto Brain Heart Infusion agar, and the surface of the agar plates was vertically irradiated with a He-Ne laser (Acusoft, 10 mW, 632.8 nm, Osada Electric Co., Tokyo, Japan). After laser irradiation, the plates were cultured anaerobically and also aerobically. Similarly, 0.13 ml of cell suspension containing CV (final concentration: 3.2 μg/ml) was placed in each well of a microtitration plate, and the laser beam was used to vertically irradiate the cell suspensions.
It was found that the bactericidal effect of He-Ne laser irradiation on S. mutans occurred only in the presence of oxygen. Moreover, the cell survival ratio was reduced as the irradiation time was extended. On the other hand, the bactericidal effect was effectively inhibited by superoxide dismutase and catalase.
It is concluded that S. mutans cells are quickly killed by He-Ne laser irradiation in the presence of CV and oxygen. Under aerobic conditions, superoxide anions and hydrogen peroxide are generated by the photodynamic action of CV, and then S. mutans cells are killed by these bactericidal products.

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The object of the present study was to examine the effect of the application of 25% potassium oxalate solution on dentinal hypersensitivity appearing on the exposed dental root surface following periodontal treatment, using a physiological saline-controlled double blind test. Observations were made for soreness, pain on exposure to air and pain on exposure to cold water at the first examination and immediately, one and two weeks after application. Statistical examination revealed significant differences one and two weeks after application, but not immediately terms of after. The treatment was effective on mild soreness, severe pain on exposure to air and mild to severe pain on exposure to cold water (for mild cases, from immediately after application). The above results indicate that the application of 25% potassium oxalate solution is effective for dentinal hypersensitivity appearing on the exposed dental root surface following periodontal treatment.

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5'-Methylthioadenosine (MTA) is formed during the biosynthesis of polyamines. We previously reported that 5'-difluoromethylthioadenosine (DFMTA), a synthetic inhibitor of MTA phosphorylase, caused intracellular adenine depletion and inhibited both alkaline phosphatase activity and bone nodule formation in cultured rat calvaria cells. In addition, exogenous adenine enhanced these two markers and partially reversed the DFMTA-induced inhibition in this culture system.
Osteopontin, a non-collagenous protein associated with matrix mineralization, has been reported to be predominantly incorporated into bone nodules in concert with the progresism of in vitro mineralization on rat calvaria cells. In this study, we examined the effects of adenine and DFMTA on osteopontin contents incorporated into mineralized nodules by using polyacrylamide gel electrophoresis and `Stains-All` staining. Adenine increased the accumulation of osteopontin into mineralized nodule whereas DFMTA inhibited it. Furthermore the osteopontin contents which had been decreased by DFMTA recovered with the addition of adenine. These results suggest that adenine formed from MTA is important in the mineralization process of rat calvaria cells.

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This study was designed to examine whether human polymorphonuclear leukocytes (PMN) exposed to oral microorganisms damage human gingival fibroblasts (Gin-1 cells) and to clarify the role of PMN in mediating gingival injury. A. actinomycetemcomitans Y 4, A. viscosus NIAH 1010, F. nucleatum ATCC 243726 or P. gingivalis 381 was incubated with PMN on Gin-1 cells labeled with ⁵¹Cr. Damage to Gin-1 cells was assessed 51 by estimating cytolysis and cell detachment.
No cytolysis was found in any of the PMN or bacterial systems through the 4 h incubation time. Injury to Gin-1 cells as a result of PMN and bacterial interaction was determined by labeled cell detachment. When Gin-1 cells were incubated with PMN alone or each bacterial species, except for P. gingivalis, there was minimal injury as determined by detachement. However, when Gin-1 cells were incubated with both PMN and bacteria adjusted in CFU, we found a significant increase in Gin-1 cell detachment which was time and PMN-dose dependent without detectable cytolysis. P. gingivalis caused a significant increase of Gin-1 cell detachment without PMN. The incubation with both P. gingivalis and PMN demonstrated the same amount of detachment as found in the sample incubated with P. gingivalis alone. No significant difference could be detected between PMN-mediated cell detachment if the concentrations of 3 the kinds of bacterial solution were adjusted to 1mg/ ml.
This injury to Gin-1 cells was inhibited by the α₁ -protease inhibitor (α₁-PI), PMSF, and 5% human serum, but not by scavengers of oxygen radicals and acid protease inhibitor. But Gin-1 cells detachment caused by PMN and F. nucleatum, which has been reported to induce large amounts of oxygen radicals formation in PMN, resisted the inhibitory effect of α₁-PI.
These results suggest that Gin-1 cell detachment might be due mainly to neutral proteases which are derived from PMN. Furthermore oxidative inactivation of α₁-PI function by oxygen radicals derived from PMN exposed to F. nucleatum was observed.

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The aim of this study was to investigate the effect of periodontal associated bacteria in plaques adhering to peri-implant tissue of osseointegrated implants. 24 implant sites in 21 subjects placed with IMZ® implants, were selected for this study. Plaques adhering to implants were examined by immunoslot blot and immunoblot assay with monoclonal antibodies that specifically recognized Porphyromonas gingivalis, Prevotella intermedia serotypes I, II, Prevotella melaninogenica and Actinobacillus actinomycetemcomitans serotype b. We also investigated the relationship between the organisms and clinical parameters. According to the result of this examination, periodontal associated bacteria were detected in 11 patients and 13 patients had undetectable. Correlation between the detected periodnotal associated bacteria and clincal parameters in the positive group were observed in probing depth and bleeding on probing.

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It is important to evaluate alveolar bone morphology precisely for diagnosis and treatment planning in periodontal therapy. Evaluation of bone loss can be accurately performed by bone sounding or re -entry . Unfortunately, these techniques involve injury and can be used on clinically only rare occasions. Image display, such as conventional radiography, can be performed without injury. But the two-dimensional nature of the transmission radiographs prevents demonstration of the three-dimensional structures in periodontal tissue.
To overcome the difficulty caused by the two -dimensional nature of conventional radiography, three-dimensional images using computed tomography (CT) were applied in this study. The results of the reproductivity and clinical performance of three -dimensional CT were as follows;
1) Highly accurate reproductivity (mean difference: 1.4±1.3%)
2) Three-dimensional bone morphology from various directions.
3) Tooth morphology showing root furcations.
Accurate performance of three-dimensional CT has the potential of allowing more precise measurement of osseous changes with less risk to the patient than was previously possible.

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The present investigation was designed to evaluate healing following the use of porous hydroxyapatite in conjunction with guided tissue regeneration (GTR) technique. Three-walled bone defects were experimentally prepared around mandibular premolars in 6 dogs. Each bone defect was filled with porous hydroxyapatite, and then polytetrafluoroethylene membranes were positioned over the defects. The other defects were treated in the same manner without the use of hydroxyapatite. As controls, the defects were treated with neither hydroxyapatite nor the membranes. The histological analysis was performed at 8 weeks after each treatment. In the control group, collagen fibers oriented parallel to the tooth surface were observed adjacent to the exposed root surface. In the defects covered with membranes only, new bone had formed which corresponded to the presurgical level. And new periodontal ligament was observed between new cementum and new bone. In the experimental group with hydroxyapatite grafts in combination with GTR-techique, hydroxyapatite was surrounded by collagen. fibers from the periodontal ligament, and were present around prepared defects. No new cementum was observed on the root surface. The results suggest that the application of hydroxyapatite grafts may have disturbed the healing procedure of GTR-technique.

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The purpose of this case study was to evaluate the effect of local application of minocycline hydrochloride as part of thetreatment regimen of a juvenile periodontitis patient.
Experimental sites were classified into four groups: tooth brushing instruction only (T.B.I.), local application of minocycline hydrochloride (M), scaling and local application of minocycline hydrochloride (Sc+M) and only scaling (Sc).
On clinical examinations, there were no significant differences among the four groups.
On microbiological tests, theSc+M group showed that the total number of bacteria was significantly decreased, Spirochaetes were uncountable and Black-pigmented Bacteroides species and Actinobacillus actinomycetemcomitans were not isolated in culture, whereas Sc and M groups showed no significant differences as compared to the first visit.
These results suggest that the local application of minocycline hydrochloride combined with debridement may be effective in the treatment of juvenile periodontitis patients.

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The present investigation was designed to assess the incidence of A. actinomycetemcomitans in adult Japanese periodontitis patients using DAN probe analysis.
Fifty-nine patients, ranging in age from 20 to 63 years, who had been referred for periodontal treatment to the Department of Periodontology of Asahi University School of Dentistry, were studied. In these subjects, 148 periodontal pockets with a depth greater than 5 mm were examined.
Mean Plaque Index, Gingival Index, bleeding on probing and probing depth measured at these 148 periodontal sites were 1.1, 1.8, 87.8% and 6.9 min respectively.
A. actinomycetemcomitans was detected in 46.6% (69 sites), and in over 50% of sites in subjects under 50 years of age. However, in 54 (78.3%) of the 69 sites in which A. actinomycetemcomitans was present, the A. actinomycetemcomitans cell count was low (>6, 000. `60, 000 cells).
Porphyromonas gingivalis and Prevotella intermedia were detected in 83.8% and 77.8% respectively, of sites. In 68 (54.8%) of P. gingivalis positive sites, the cell count was high (>6, 000, 000 cells).
The results demonstrate that A. actinomycetemcomitans can be detected in a high proportion of Japanese subjects by DNA probe analysis.

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In this study, we immunohistologically detected plasma cells bearing immunoglobulins reactive to human γ A-globulin (IgG) in gingivae from patients with various types of periodontitis. In order to detect these cells, we developed an immunohistological method using human IgG conjugated with horseradish peroxidase (HRP). 41 subjects were grouped into 3 different types of periodontal disease; adult periodontitis (AP), early onset periodontitis (EOP) and hyperplastic gingivitis (HG), according to their histories and clinical findings. On analysis of all 63 specimens from 41 subjects, plasma cells bearing immunoglobulins reactive to IgG were detected in 14 specimens from 9 subjects. These cells were observed in all groups and their existence ratios increased in the order of AP, HG and EOP. In almost all specimens in which plasma cells bearing immunoglobulins reactive to IgG were detected, these cells existed in the subepithelial connective tissues where plasma cells and lymphocytes tended to form clusters. In this study, it was unclear whether the existence of these cells related to clinical parameters. But the presense of many plasma cells bearing immunoglobulins reactive to IgG was confirmed in some phases of early onset periodontitis, suggesting that specific antibodies to human IgG are produced in gingiva affected by human periodontitis.

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Our previous study demonstrated that no morphological changes occur in deep cementum of periodontally involved teeth. However, the tested teeth were consisted of mainly vital teeth rather than non-vital teeth. The present study was undertaken to statistically analyze morphological changes in the cementum of periodontally involved teeth with various pulpal status. Seventy-three periodontally involved teeth were used. They were divided into two groups (the first group consisted of 39 teeth ; probing pocket depth<5mm, and the second consisted of 34 teeth ; probing pocket depth DATA 5mm). Each group was subdivided into 5 . categories according to pulpal status, 1. vital teeth, 2. obturated teeth, 3. colored obturated teeth, 4. teeth with infected root canals, 5. colored teeth with infected root canals. After splitting the extracted teet longitudinally, root fragments were processed for SEM. A total of 73 fractured surfaces were evaluated for statistical analysis of morphological changes. There were no morphological changes in deep cementum of vital and non-colored obturated teeth, while those of colored teeth and teeth with infected root canals showed significant changes in both groups, with pockets 5 mm and pockets. DATA 5mm. These results suggested that the deep cementum in vital and non-colored obturated teeth were healthy.

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An experimental group used a 1200-1300-gauss tooth brush, and a control group used a 30-gauss tooth brush. Each group, which consisted of 10 adults with normal gingival, was instructed not to move the tooth brush for a short while (15 seconds, 30 seconds, and 60 seconds), and then toothbrush for 15, 30 and 60 seconds. Change of gingival blood flow were observed using a laser speckle blood flowmeter after each brushing. The gingival blood flow volume was determined at the attached gingiva of the central labial part of the upper centralinicisor for 5 minutes in the experimental and control groups, and changes in the blood flow volume were obtained:
1) The blood flow volume was higher in the experimental group than in the control group throughout the period of determination, the difference being statistically significant (p<0.05, p< 0.01) in the subjects who did not move the toothbrush for 15, 30 and 60 seconds.
2) The blood flow volume was higher in the experimental group (consisting of the subjects who brushed for 15, 30 and 60 seconds) than in the control group throughout the period of determination, the difference being statistically significant (p<0.05, p<0.01) in the subjects who brushed for 15 and 30 seconds.

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The object of the present study was to make a comparative examination of the effectiveness in acute symptom of periodontitis between single administration of Periocrine ® and the conventional treatment including 'intra-pocket washing and oral administration of antibiotics'.
Both these treatments obtained clinical improvements in pain, swelling and drainage, but single administration of Periocrine ® and the conventional treatment including 'intera-pocket washing and oral administration of antibiotics' were effective and ineffective, respectively on redness. Overall judgment of effects on redness. Overall judgment of effects revealed no statistically significant difference there between, while doctors in charge judged single administration of Periocrine ® to be superior. Besides, single administration of Periocrine ® showed a tendeny to earlier clinical improvement compared with the conventional treatment.
The above results indicate that single administration of Periocrine ® which can be expective of satisfactory clinical effect in acute symptom of periodontitis is a very effective therapeutical approach thereto in view of its quick action, burden to patients, time required for treatment.

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The clinical and microbial effects of Periocline ® administration in periodontal pockets, in combination with scaling, were exmined in patients using two delivery systems and root planing. Three different sites, one in each quadrant, were randomly selected in each of 10 periodontal patients participating in this study. Each patient received the following treatment: Periocline ® was administered four times at one-week intervals in combination with scaling at one site, Periocline ® was administered two times at two-week intervals in combination with scaling at another site, and root planing alone at the third site. The three groups showed similar effectiveness throughout the observation periods, clinically as well as bacteriologically (phase contrast microscopically).

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