We have examined the distribution of fibronectin in rat periodontal tissue after gingivectomy by either electrosurgery or conventional surgery. Gingivectomy was performed at the maxillary palatal site in male Wistar rats with an electrosurgical unit or scalpel knife. Animals were sacrificed at 12 hours, and 1, 3, 5, 7 and 14 days after surgery. Block specimens were fixed in formalin, decalcified with EDTA, made into serial paraffin sections, and examined after hematoxylin -eosin staining, after Masson-trichrome staining and by indirect immunofluorescence for the presence of fibronectin. Following gingivectomy with the scalpel knife, fibronectin was detected in the fibrin clot on the wound surface, and migratory epithelial cells which had crossed over this fibrin clot were observed (12 hours-1 day).
In contrast following gingivectomy with the electrosurgical unit, no fibrin clot was present on the wound surface, and fibronectin was deposited at the level of the connective tissue beneath migratory epithelial cells. Thus, early wound healing was delayed electrosurgery as compared with conventional scalpel knife surgery. In both wound types, fibronectin was deposited heavily in granulation tissue, but the deposition peak was on the 5th postoperative day with scalpel knife wound and on the 7th with electorosurgical wounds. The distribution of fibronectin was similar in the two wound types 14 days after surgery. These results suggest that early delay in wound healing after electrosurgery is caused by the absence of fibronectin, which is associated with cell chemoattraction and attachment.

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The subgingival microflora and periodontal condition were examined in patients with diabetes mellitus, adult periodontitis, and refractory periodontitis. Subgingival plaque was sampled from the deepest periodontal pocket in each of 50 patients with diabetes mellitus, including 44 (88%) with NIDDM and 6 (12%) with IDDM. The level of blood sugar of 88% of the deabetic subjects was increased, whereas 78% of the same subjects had a low fructosamine level. The total of cholesterol (88%), neutral fat (68%) and HDL (78%) level of the subjects were normal.
The clinical status of patients with NIDDM, IDDM, adult periodontitis, and refractory periodontitis was evaluated by using clinical parameters such as PlI, GI and PD. The mean values of PlI were similar in the subjects with NIDDM (1.4±0.1), IDDM (1.3±0.4) and refractory periodontitis 1.0±0.2), whereas that in adult p (eriodontitis 0.3±0.1) was lower. The mean va (lues of GI were similar in the subjects with NIDDM (1.7±0.1). IDDM (1.8±0.2) and refractory periodontitis (2.0±0.0) whereas that in adult periodontitis 0.7±0.2) was lower, similar to PlI. (The mean PD of refractory periodontitis (6.9±0.5mm) and adult periodontitis (6.0±0.6mm) were deeper than those of IDDM (5.2±0.2mm) and NIDDM (4.7±0.3mm), DNA probe for Porphyromonas gingivalis(Pg), Prevotella intermedia (Pi), and Actinobacillus actinomycetemcomitans (Aa) were used to examine the patient's samples as well as 22 additional subginival plaque samples from 10 sites of 11 patients with adult periodontitis and 12 sites of 2 patients with refractory periodontitis. Microbiological analysis of subgingival plaque sampled for this study of periodontal pathogenetic bacteria substantiated the results of DNA probe. Aa (25.0%) and Pg (54.5%) were thought to be pathogens of NIDDM. A few samples taken from subjects with IDDM, however, had the same propotion of pathogenetic bacteria as those with NIDDM Aa 58.3%) and Pg (66.7%) were detected in the subjects with refractory periodontitis, whereas only Pg (70.0%) was found as a pathogen in adult periodontitis. Pi was not recovered from IDDM, adult periodontitis, or refractory periodontitis, and from only 4.5% in NIDDM.
The arithimetic means obtained as the results ofDNA probe studies were statistically higher (p< 0.01) for Pg and Aa when the values were correlated with PD (4. PD<7) and GI (GI 2).
These findings demonstrated that diabetes increases the risk of developing destructive periodontal disease. In NIDDM and IDDM, Pg is the most frequently detected microorganism, accounting for 54% of the total sampled sites, followed by Aa, which accounted for 24% of the total. Pg was the most prevalent microorganism, in refractory periodontitis, being found in 66.7% of the sampled sites, followed by Aa, which accounted for 58.3% of the total. Clinical and microbiological data from the present study suggest that the diabetic patients with periodontitis are more similar to nondiabetic patients with refractory periodontitis than adult periodontitis.

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The purpose of this study was to assess the extent of bacterial invasion into periodontal tissues during experimental periodontitis in rats. Forty-six conventional (CV) rats and 36 germfree (GF) rats were used for this experiment. Mechanical stimulation was achieved by applying a small elastic ring around the cervix of the mandibular first molar (M 1). The ring produced continuous pressure against the periodontium which eventually produced a periodontal pocket. Bacteria were introduced around the cervix of M 1 by applying 5×10⁸ colony forming units of Porphyromonas gingivalis (P. gingivalis) in 0.05ml of saline solution, 7 days after the application of the elastic rings. Histopathological evaluation of periodontal status was made 1 hour after the application of P. gingivalis using light microscopy and transmission electron microscopy.
Results:
1. The elastic rings, applied around the cervix of the M 1, produced periodontal pockets and caused alveolar bone resorption in CV and GF rats. The degrees of inflammatory cell infiltration and alveolar bone resorption were decreased in GF rats as compared to CV rats.
2. Numerous polymorphonuclear leukocytes (PMNs) were observed on the surfaces of ulcerated areas in mechanically stimulated CV rats. Bacteria were observed in the PMN zone on the surface of ulcer. Most bacteria had been phagocytized by the PMNs. Bacteria were not observed in deeper connective tissue zone.
3. In GF rats and non-mechanically stimulated CV rats, bacteria were not observed in periodontal tissues.
Discussion and conclusion:
In these experimental models, it is rather difficult to distinguish actual bacterial invasion from passive bacterial presence in the epithelial cell layer gap. It is concluded that even though there is ulcerative lesion on the periodontal pocket wall, bacterial invasion into deeper connective tissues is effectively prevented by PMNs.

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In order to investigate age-related changes in the periosteal microvasculature, the alveolar periosteum of the lingual side of the lower first molar region of the rat was examined in detail. Male Wistar rats aged 1, 3, 6, 12 and 24 months, whose microvascular architectures were successively studied by scanning electron microscopy, were used for this study. In addition, the ultrastructure of blood vessel endothelium, as it involved permeation, was observed by means of a tracer under transmission electron microscopy. The results indicate that, as the periosteum ages, changes in the morphology of the osteoblasts are accompanied by changes in the distribution of the microvasculature in addition to reduce the endothelial permeability. In fact, active transformation of osteoblasts in the bone matrix during the first 3 months of life was accompanied by formation of dense networks of fenestrated capillaries around the osteoblasts. This was verified by permeation of a tracer, mainly through the fenestrations. By 6 months of age, during a resting stage in the process of osteogenesis, with alomost no observable activity, the microvasculature tended to be sparse with capillaries being of the continuous type. During this period, the tracer was clearly observed to permeate the capillary wall via vesicles.

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The present study was designed to compare the reparative processes of free gingival grafts, which were secured apical to the mucogingival line, placed on the periosteum and on the denuded bone from the point of view of destruction and regeneration of the periodontium. The recipient sites were prepared at the incisor and premolar regions of 9 adult Beagle dogs, with periosteum on the right, and without periosteum on the left. The reparative processes were evaluated at 1, 2 and 4 weeks, and 2, 3, 6, 12 and 24 months postoperatively.
When placed on the denuded bone, first stage macroscopic healing was delayed by about 1 week as compared with periosteum placement, although there was no gingival recession. Microscopic healing revealed severe bone resorption only at the side without periosteum within a few weeks of the grafting. However, new bone formation along the root preserved periodontal ligament cells occurring about 3 months after grafting. Healing on the denuded bone seemed to generally be carried out in the periodontal tissue complex consisting of ligament, cementum, bone and gingiva in the presence of surviving ligament cells, while healing on the periosteum was taking place in the soft tissue limited to gingiva and alveolar mucosa. It was speculated that the repair, as a periodontal tissue complex, would lead to recovery of esthetics without a conspicuous boundary line between the donor and surrounding tissue.
From the aspect of destruction and regeneration of the periodontium, the results suggest that periodontal ligament cells play an important direct role in reconstruction of the periodontal tissue complex, although the amount of newly formed bone is affected by systemic and environmental conditions. The present study concerning the periodontal tissue repair suggests that destruction is closely related to inflammation, and regeneration to periodontal ligament cells.

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I examined the morphological features of attachment on various root surfaces following guided tissue regeneration (GTR). Experimental periodontitis was induced on the canines and incisors of 16 adult monkeys. The monkeys were divided into 4 groups and received one of the following root surface preparations at flap surgery: 1) root planing, 2) root planing with application of citric acid, 3) curettage of the superficial cementum, 4) curettage of the superficial cementum with application of citric acid.
Membranes (Millipore® filters) were adjusted over the experimental teeth on the left side, while the contralateral teeth were membrane free and served as controls. The time course of new attachment formation in each group was examined histologically at specific points including 1, 2, 4 and 8 weeks after surgery. The following results were obtained. Up to 4 weeks, periodontal healing of the experimental groups was delayed as compared to that of controls. At 1 week, granulation tissues in the periodontal spaces between the membranes and the roots (the curetted dentin and cementum surfaces) of the experimental groups were more coronally located than those of controls.
Statistical analysis showed no significant differences in the amount of connective tissue attachment between the experimental and control groups except in those with planed dentin surfaces. No significant differences were found between the experimental and control groups as to new cementum formation and bone regeneration.
The ultrastructural features of attachment between the regenerated periodontal tissue and each root surface were similar in the experimental and control groups. Newly formed collagen fibrils had accumulated in parallel to the planed dentin surface and inserted vertically into the curetted cementum surface. They appeared to be linked with the exposed collagen fibrils on the demineralized dentin and cementum surfaces. Thus, the results indicated that the root surface condition determined the type of attachment, regardless of the migration of specific cells.

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The purpose of this study was to develop a biodegradable fibrous collagen membrane in place of the nondegradable membranes currently used for the guided tissue regeneration (GTR) technique. We produced collagen membranes in several ways and examined the velocity of membrane degradation by fundamental experimentation with rats.
Firstly, we delayed the velocity of membrane absorption by artificial cross-linkage with hexamethylenediisocyanate (HMDIC) and also tried to control the absorption rate by using different concentrations of HMDIC. As a result, the fibrous collagen membrane treated with 10% HMDIC was not absorbed until 4 weeks after the membrane had been implanted in the back skins of rats. However, findings from examination of membranes implanted in the gingiva at the palatal site of the maxillary right first molars indicated that the membrane was absorbed within 2 weeks of the implantation.
Secondly, we developed a cross-linked fibrous collagen membrane the thickened fiber of which was produced by dialysis at 4.. for 48 hrs., and evaluated the absorption of this membrane. The results indicated that the membrane had not been absorbed until 4 weeks after implantation in back skin and 2 weeks after implantation in gingiva. These findings suggest that cross-linked fibrous collagen membranes may have clinical application in the GTR technique.

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The purpose of this study was to evaluate the effect of using the cross-linked fibrous collagen membrane (which we reported in part I) for a guided tissue regeneration (GTR) technique in areas involving the site of tooth furcation.
The maxillary and mandibular molars of monkeys (Macaca Irus) were used. At the sites of furcation of the teeth, surgical bone defects (class II or class III) were made and the exposed root surfaces were planed for elimination of the cementum. Test and control groups underwent the same procedure, but in the test group, the membrane were for GTR. The period of observation was for 2, 4 and 8 postoperative weeks after which clinical examination, histopathological observation and histometrical measurements were performed.
On clinical examination, there was no significant difference between the two groups although probing depth and clinical attachment loss at 2 weeks after surgery were greater in the test group than in controls.
Histopathological observation indicated that the test group had suppression of epithelial invasion during the early stage of wound healing and good regenration of alveolar bone and cementum during thefollowing stage as compared with the control group. This tendency was especially marked in the absence of invasion of the epithelium. These findings suggest that use of the cross-linked fibrous collagen membrane in the GTR technique has great clinical potential.

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The purpose of this study was to improve the conventional method we have been using used for evaluation of serum IgG antibody titers.
In previous studies, patient sera were serially diluted and absorbance at 410 nm was measured with enzyme linked immunosorbent assay (ELISA). The dilution and absorbance were plotted on X-and Y-axes, respectively. The antibody titer was defined as log₂ of the serum dilution at the intersection of 0.8 absorbance.
In this study, a standard serum was prepared from blood (for transfusion). The antibody titers of this standard serum against four bacterial strains, Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans and Fusobacterium nucleatum, were determined. Antibody titers of 24 patient's sera against these bacterial strains were then measured ten times to ascertain the reproducibility of data obtained by the improved method.
The results were as follow:
1. This improved method is capable of analyzing six times more samples than the conventional method.
2. The reproducibility of results obtained by the improved method was greater than that of the conventional method.
3. Sera, in which titers were higher than nine with the conventional method, had nearly the same titer with the improved method. However, when titers were less than nine with the conventional method, the titers were higher with the improved method.
These results indicate that the improved method was effective in screening high-titer sera.

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Proteoglycans in alveolar and non-alveolar regions of canine mandibular bone were extracted and separated by gel-filtration and SDS-polyacrylamide gel electrophoresis. Furthermore, qualitative and quantitative analysis of glycosaminoglycans liberated from these proteoglycans was performed to characterize the proteoglycans in alveolar bone as compared to those in non-alveolar bone. Proteoglycans in bone tissues were successfully extracted under demineralizing conditions achieved in the presence of 0.25M ethylenediaminetetraacetic acid. The amount of proteoglycan in alveolar bone was less than 50% of that in non-alveolar bone. The molecular weights of proteoglycans partially purified by CsC1 centrifugation ranged from 70, 000 to76, 000. It is possible that two different low molecular weight forms exist in bone. The glycosaminoglycans extracted from the proteoglycans consisted mainly of chondroitin sulfate in both alveolar and non-alveolar bones.

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The goal of periodontal surgical therapy has concentrated on regeneration of periodontal ligament tissue, in which fibroblasts are stimulated to synthesize and secrete collagen. The purpose of this study was to demonstrate the effects of stimulatory factors on the initial wound healing phase in vivo in a standard experimental wound healing model. Six empty Teflon chambers (8mm diameter×20mm long tubes) were surgically implanted subcutaneously in the abdomens of rats in a symmetrically paired fashion. Carrier PBS solutions, each 500μl, with growth factors or without, were injected into the chambers once a day for five consecutive days.
In 36 rats, the chambers were divided into the following groups; 1. TGFβ (0.5ng), 2. TGF-β(1.5ng), 3. TGF-β(5ng), on the right and I′. TGF-β(5ng) +EGF (20ng), 2′. BSA (3ng), 3′. PBS in the left. The chambers of other 36 rats were divided; 4. collagen (30μg), 5. collagen (100μg), 6. collagen (300μg) on the right and 4′. TGF-β(1.5ng) +EGF (6ng), 5′. BSA (100μg), 6′. PBS on the left. Left-sides chambers for BSA and PBS were used as controls.
On days 3, 5, 9 and 12, 3 rats from each group were sacrificed. Healing responses were observed in terms of the degree of infiltration of cellular components and amounts of protein, DNA and collagen hydroxyproline, namely the chambers were carefully removed from the rats and the contents of exudates and granulation tissues were determined. The granulation tissue were then fixed and the paraffin sections were stained with Azan.
Exudate cell numbers were low on the 3rd day and there were no effects of these factors on the other exudate data until the 12th day.
The microscopic examination showed that significant formation of collagen had occurred during the period 3 days treatment with TGF-β in concentrations of 0.5 or 1.5 ng. A significant amount of collagen was also found in granulation tissue terated with collagen for 12 days. The amounts of DNAin the granulation tissue of chambers which had been treated with TGF-β, were highly significant on the 9th and 12th days. However, lower amounts of DNA and diminished or absent collagen formation were observed in granulation tissue treated with TGF-β+EGF. These data indicate that TGF-β alone might accelerate cell migration, thereby producing collagen in the early healing stage, and might act on cellular growth and differentiation in the later stage.

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In an attempt to promote synthetic bone implant material, tricalcium phosphate-collagen immobilized tetracycline complex (TCP-C-TC) was produced on a trial basis, and the usefulness of this material was assessed.
TCP-C-TC was produced as follows: TC was dissolved in 0.5% atelocollagen solution (pH 3, 100 mg/ml), and TCP was immersed in the solution under vacuum, neutralized with ammonia gas, then cross-linked by ultraviolet irradiation for 30 min. In testing, the determination of drug delivery was performed by caliburation of spectrophotometolly and antibiotic activity. And the effect of TCP-C -TC on tissue regeneration was examined histopathologically.
As the results, released TC was maintained at effective levels until 5 days. No marked difference in tissue regeneration was found between the TC treated and non-TC treated group.
These results suggest that the TCP-C-TC is effective pharmacologically and useful as a implant material for bone defects in periodontal therapy.

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The condition of gingival crevicular fluid (GCF) has been regarded as the best reflection of the state and severity of periodontal tissue destruction due to periodontal disease. Qualitative and quantitative analyses of GCF can provide important clinical diagnosistic information necessary for periodontal therapy. This study was designed to determine whether GCF protein concentrations may be an indicator of the severity of periodontal disease. The subjects were 23 first visit patients with adult periodontitis (14 women and 9 men), whose mean age was 52.7 years with a range of 30-83 years. Ninety-three different sites with radiographic evidence of alveolar bone loss were randomly selected. The clinical parameters used in this study were Plaque Index, GCF volume, probing depth, attachment level, Gingival Index and tooth mobility. GCF was collected with a filter paper strip (Periopaper ®) inserted into the gingival sulcus to a level 1mm below the gingival margin for 3 min. Each strip was subjected to volume determination with a Periotron ® 6000 and protein measurement by Lowry's method.
As a result, the relationships between protein concentrations and the aforementioned clinical parameters were all statistically significant at p< 0.01 by Spearman's test. The correlation coefficients were 0.41, 0.70, 0.31, 0.29, 0.60 and 0.39, respectively. Among these, protein concentrations and GCF volume correlated remarkably well. It was suggested that GCF protein concentrations may be an important indicator of periodontal breakdown because GCF volume is considered the most objective and effective parameter.

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The present clinical study was conducted to investigate the effects of different methods of administration, and of the environment of the site of application, on retention of minocycline in periodontal pockets.
Minocycline was applied by oral administration, irrigation of periodontal pockets, or infusion in the pockets with slow-release ointment. The concentration and percent retentions of minocycline in the pockets were determined daily and compared among the three routes of drug administration used in these groups. In addition, the group receiving slow-release ointment infusion was investigated as to the effects of pocket depth and the severity of gingival inflammation before the administration. The concentration of minocycline in the pockets was determined by the HPLC.
The results showed that, in the group given minocycline orally, the rate of retention was 100%, but the drug levels were maintained for less than one day and the concentration was lower than with local application. In both the irrigation and slow -release ointment infusion groups, the retention of minocylcline decreased from 3 days to 5 days of application. The group which received the slow -release ointment infusion exhibited excellent retention of minocycline in deep pockts without gingival inflammation.

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The purpose of this study was to examine the status of periodontal disease in young female students, and to estimate the reliability of a screening method using CPITN in a large population. A primary examination of 1444 female junior and senior high school students was conducted in Sendai. The upper first right and left first molars, upper right first incisor, lower right and left molars and lower first left incisor were selected as the index teeth. Forty three subjects (approximately 3% of all students examined) who had CPITN values of more than 13 or who had one or more code 4 teeth were selected for secondary examination at the Dental Hospital of Tohoku University. Periodontal pocket depth, bleeding index and the presence of calculi were determined. A third examination was conducted on 36 students to measure alveolar bone loss using full mouth radiographs. The prevalences of both code 1 and code 2 were approximately 80% in each high school grade. The prevalence of code 2 increased with age and decreased in proportion to those of code 0 and code 1. The results of the primary examination were in 100% agreement with those of the secondary examination for code 0, 65.5% for code 1, 71.1% for code 2, 66.1% for code 3, and 33.3% for code 4. Slight or moderate alveolar bone loss was observed in all of the students who underwent the third examination, suggesting that they were suffering from mild to moderate periodontitis. In conclusion, the periodontal examination using CPITN was reliable for primary screening of large populations.

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Clinical, histopathological and bacteriological aspects of chronic desquamative gingivitis were studied in afflicted patients. Clinically, there was a deteriorative stage in which the gingiva showed marked epithelial exfoliation with a glossy erythematous appearance, and a remissive stage in which these features abated, the two stages showing peri odic alteration. Histopathologically, the parakeratinized epithelium was thinned, with short or absent rete pegs, and inflammatory cell infiltration was evident in epithelial intercellular spaces; extensive lymphocyte infiltration was seen beneath the epithelium. There was also hydropic change in the basal cell layer and micro-bulla formation beneath the epithelium. Electron microscopically, amorphous substances were observed in the space created by separation of basal cells and the basal lamina. The basal lamina showed tearing, and desmosomes were decreased in number. Bacteriologically, there was no correlation between the deteriorativeand remissive stages with regard to bacterial counts, proportional distribution of gram- positive and gram-negative bacteria, or colony counts of bacteria from saliva, gingival crevicular fluid, tongue plaque, and periodontal pockets.

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This study was undertaken to know the occlusal parafunctions which may cause occlusal traumatism in periodontitis patients. Thirtyseven moderate to severe periodontitis patients and 18 healthy control subjects were used. They answered the questionnaire, received clinical occlusal examinations and MKG/EMG tests with K-6 diagnostic system. As a result, contact velocity in mouth closure was slower, and chewing strokes terminated in multipul points in patient group. These results may be contributed by the unstability of intercuspal position in periodontitis patients. In function EMG mode, patient group tended to show lower EMG level compared to control group, but no difference were found in the rest mode.

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The purpose of this study was to evaluate the clinical effects of Periodontitis-medicinal gel PMG), consisting of Dipotassium glycyrrhizinate, (Allantoin, Hinokitiol, Cetylpyridinium chloride etc. on several types of gingivitis, periodontitis and stomatitis. A total of 93 patients with gingivitis or periodontitis were randomly selected for this study from the three institutions involved. Another 42 patients with stomatitis were also examined in two institutions. Following PMG application to gingival tissues, clinical findings were examined at weekly intervals for 4 weeks. Analysis of variance was performed to determine the significance of differences between subjects, as well as the durations of post-treatment periods. After making a comparison between baseline and final data, total improvement rates were calculated. The results are summarized asfollows:
1) Seventy six percent of gingivitis andperiodontitis patients showed at least moderate improvement, 32% of these cases having marked improvement as compared to their baseline conditions. In addition, 73% of cases experienced sufficient amelioration of their gingivitis orperiodontitis for PMG to be judged effective. All patients suffering from stomatitis demonstrated moderate improvements with PMG being consideredeffective in98% of cases.
2) During these experiments, four patients with gingivitis or periodontitis and two with stomatitis showed local side effects consisting of temporary stimulation. However, these occurrences were accidental and had so systemic effects.
These results indicate that PMG is useful for treating gingivitis, peridontitis and stomatitis.

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The purpose of this study is to determine the prevalence of periodontal disease and the relationship between an individual's awareness of periodontal disease and the actual clinical state of periodontal tissues, and to attempt implementation of the “Expert-System Using Neural-Nets” which is designed to predict individual probing depth. This new approach is based on cognitive science.
We utilized epidemiological data sets obtained from our previous study conducted on 3, 886 junior and senior high school students (12 to 18 years of age) living in Kawagoe, Japan. The inputs to learning are composed of answers to questionnaire items related to the progression of periodontal disease (decrease in tooth brushing times per day, history of consultation on oral hygiene instruction, gingival swelling, gingival bleeding on tooth brushing, history of a dental diagnosis of periodontal disease) and the actual probing pocket depth. The prediction of individual probing depth is obtained only on the basis of the questionnaire answer. Furthermore, in addition to assessing gingival inflammation by means of intraoral examination, we can also obtain the prediction.
Then, we compare the prediction of individual probing depth with the actual depth.
The following results were obtained:
In cases in which only the questionnaire answer related to the progression of periodontal disease was obtained, there was a 70±8% correct prediction rate of probing depth on testing patterns which were not utilized for learning. Furthermore, in addition to the intraoral examination assessment of gingival inflammation, we obtained an 88±7% correct prediction rate on testing patterns.
The results of this study suggest that the “Expert -System Using Neural-Nets” is useful for examining the relationship between questionnaire results and periodontal disease in youth.
In the near future, if the need arises for a reliable screening system for periodontal disease, the “Expert -System Using Neural-Nets” presents a likely solution.

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This double blind clinical study was designed to examine the clinical effects of an aluminum chloride and zinc sulfate solution on dentin hypersensitivity. The results were as follows: 1. The effectiveness of the solution on affected teeth was 89.2% with rubbing stimulation, 76.3% with cold water stimulation, and 71.6% with cold air stimulation, each showing a significant difference from the control group. Similar effectiveness was also achieved among patients. 2. As time passed, the effectiveness increased as follows: with cold water stimulation, 30.3% after 3 days, 45.8% after 1 week and 76.3% after 2 weeks, and with cold air stimulation, 20.8% after 3 days, 33.3% after 1 week and 71.6% after 2 weeks. With rubbing stimulation, the test group proved slightly more effective after 3 days (the test group 21.7% and the control group 20.8%) ; however, the effectiveness of the test group surpassed the control group after the first and second week, with the variation between these group increasing over time. 3. No adverse side effects were observed. In a questionnaire on the sensation of using the solution, 46.7% of the test solution users and 39.3% of the control solution users responded “good”. From the above results, the solution can be regarded as effective against dentin hypersensitivity.

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The present clinical study was performed to ascertain the optimum time for antibiotic administration by a local drug delivery system in combination with root planing (RP).
Minocycline slow-release ointment was applied locally either before or after, or both before and after RP (once/week for 4 weeks). The plaque index, gingival index, bleeding on probing (BOP), probing depth and probing attachment level were determined during a clinical examination conducted on the first visit, and immediately before and 2 months after RP.
The local application of minocycline slow-release ointment before RP was found to decrease the rate of BOP and increase clinical attachment levels. It was also found that the rate of probing attachment gain increased after RP in sites without BOP before RP.

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This study was carried out to know the states of cases which had been done periodontal surgery from January, 1990 to December, 1991 in our clinic and to compare these results with those of 5 years ago.
The following results were obtained.
1. The operation cases were 176 (107 males and 69 females) and the average age of the patient was 47.3 years.
2. The progressive stages of periodontitis at the time of surgery were as follows. severe: 63.5%, moderate: 36.6%, mild: 0%.
3. The main purpose for surgery was elimination of periodontal pockets (65.1% of cases), followed by improvement of furcation involvements .
4. As regards the classification of these opera tions, there were 159 flap operation cases, 57 periodontal osseous surgery cases and 38 furcation involvement cases.
5. Before these operations, 85.5% of the cases had been done reevaluation. According to the results of the preoperative evaluation, the plaque control record was under 20% in 58.6% of the whole cases and the bleeding index was under 20% in 74.2% of the whole cases.
6. The flap operation had been done mainly to the 5 mm pocket depth cases. There were remaining calculus in deeper pockets.

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The aim of this study was to evaluate the clinical effect of the guided tissue regeneration (GTR) technique using a expanded polytetrafluoroethylene (EPTFE) membrane (Gore-Tex®, periodontal material). Sixty teeth in 52 patients (22-66 years, 19 males and 33 females) with adult periodontaldisease were used for this study. After completion of the initial preparation, plaque index, bleeding on probing, probing depth and clinical attachment level were measured. Following flap elevation, scaling, root planing and removal of granulation tissue, the membrane was placed. The flaps were repositioned and sutured. After one month, the membrane was removed. After 3 and 6 months, clinical parameters were re-evaluated. At the 6 month post-operative evaluation, furcation involvements sites (21 teeth) showed 3.36±2.08mm pocket reduction (probing depth was reduced from 5.83±2.17mm to 2.48±0.66mm) and 2.64±2.55mm attachment gain. Vertical defect site (39 sites) showed 3.45±1.43 mm pockt reduction (probing depth was reduced from 6.08±1.68mm to 2.58±1.06mm) and 1.77±1.77mm attachment gain. The probing depth and attachment level were significantly improved. This study suggests that GTR using the EPTFE membrane is effective for treatment of furcation involvements and vertical osseous defects in periodontal desease.

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