To evaluate the safety of dentifrice and mouthwash solution, we investigated the influence of sodium lauryl sulfate (SLS) and glycerine contained in most of the commercially available dentifrice and mouthwash solution on various cells. The effect of various concentrations of SLS on the morphology of human keratinocytes was observed. As a result, immediately after applying 0.01% SLS, a decrease in the size of the cells was observed, then most of the cells showed lyses and disappeared in one minute. In cases of applying 0.001% SLS, a decrease in the size of the cells started three minutes after application ; however, the rate of the decrease was small. After applying various concentrations of SLS to human erythrocytes, the morphology of the erythrocytes changed from the normal discocytes to the echinocytes depending on the concentration of SLS. In cases of applying more than 0.004% SLS, the erythrocytes showed hemolyses one minute efter application. After applying various concentrations of SLS to normal human aortic endothelial cells (HAEC), in cases of applying more than 0.0022% SLS, the cells showed changes one minute after application, then most of the cells showed lyses and disappeared in five minutes. After applying glycerine to the various cells, the damage to the cells by glycerin was not great under the conditions of low concentrations and short periods of application. Observation of the action- sites of SLS on the human erythrocytes suggested the involvement of membrane proteins.
From these findings, it is necessary to be careful wit h the use of SLS and glycerine, especially because even a minute amount of SLS caused damage to the various cells. J. Jpn. Soc. Periodontol., 43: 1-12, 2001

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We studied the correlation between periodontal disease and osteoporosis by comparing panoramic radiographic and clinical parameters of periodontal disease. Diagnosis of osteoporosis in periodontal disease patients was evaluated by panoramic radiographic parameters.
Subjects were 226 untreated adults with periodontal disease-113 women and 113 men-who were free of other systemic diseases. Each subject had more than 20 teeth and was examined by panoramic radiography. The following parameters were examined on panoramic X-ray film: alveolar bone loss (ABL), mandibular bone mass with the use of mandibular cortical width (MCW), and Central panoramic mandibular index C-PMI). Subjects were stratified into 10-year spans (from 20 to 70 years). Women were divided into pre-and postmenopausal groups and postmenopausalsubdivided into 1-5, 6-10, and>11 years postmenopausal groups. For each groups, we analyzed the correlation between these parameters and clinical parameters, including the number of teeth, plaque control, clinical attachment level (CAL), gingival index, gingival bleeding index, and mobility. Diagnosis of osteoporosis was determined by MCW.
No significant differences were seen between men and women except for MCW. ABL was significantly higher and MCW significantly lower in the postmenopausal group (>6 years after menopause). The number of teeth was significantly lower and CAL significantly higher in the postmenopausal group (>11 years after menopause). Age and ABL correlated positively in men and women. Age and number of teeth, age and ABL, and MCW and ABL in women correlated positively. Years after menopause and ABL and MCW and CAL in the postmenopausal group were correlated positively. Two women whose MCW was less than the mean -2 SD were diagnosed with osteoporosis.
Our results demonstrated that periodontal disease correlates with osteoporosis, and MCW could be useful in detecting of osteoporosis in women with periodontal disease. J. Jpn. Soc. Periodontol., 43: 13-24, 2001.

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Sickly change around root divergence is determined to be a morbid state where tooth-surrounding tissues of a compound root tooth have been destroyed. A compound root tooth has a rather complicated shape when compared to a single root tooth, and it is therfore difficult to treat surrounding teeth.
Causes of root divergent morbid changes are considered to be pocket formations due to the progress of chronic marginal periodontitis, abnormal states of a tooth crown such as enamel promontories, floor of pulp chamber, and lateral branch caused by pulpitis, and incomplete treatment of inside teeth. Injuries due to tooth occlusion are also considered to be a secondary cause of these morbid changes, with it is believed, occur due to a single or complex combination of the above factors.
Enamel promontories, regarded as one cause of morbid change around root divergence, arrest compound tissue attachment, friggring plaque accumulation. This leads to attachment loss, followed by periodontitis. Because of this Master and Hoskins divided the cause of enamel promontories into 3 stages.
Because root morbid divergent changes have many different causes, Grickman suggested that this stage should be divided into 4 stages while Lindhe & Nyman suggested division into 3 stages.
Initial treatment was conducted against morbid changes in root divergence of the first molar in the lower chin on both sides, caused by enamel promontories appearing with the frequency of 30% in clinical cases in this study. Since Lindhe and Nyman suggested 2 classifications for morbid root divergence chages of the first molar on the left side of the lower chin, treatment was done using a classifications of 2-3 degrees. Al though Lindhe and Nyman sugested 3 degrees, we foused on using their 1 degree classification in treatment. We report the favorable treatment progress. J. Jpn. Soc. Periodontol., 43: 25-32, 2001

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Using a PCR method, we detected periodontopathic microorganisms in inflamed gingival tissues from patients with adult periodontitis, which included the four fimA genotypes(types I to IV) of Porphyromonas gingivalis (P. gingivalis), as well as Treponema denticola (T. denticola), Bacteroides forsythus (B. forsythus), Prevotella intermedia (P. intermedia), and, Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans). The inflamed tissues were taken during periodontalflap operations, while subgingival plaque samples at the same site were collected just prior to the operation or, in some cases, during the maintenance period. Our results indicated that all of the microbes examined in this study were detected in the gingival tissue samples. In particular, P. gingivalis, T denticola, and B. forsythus were frequently detected (100%, 81.4%, and 64.3%, respectively). Similar results were obtained from the plaque samples taken just before the operation, suggesting that all of these microbes areable to exist in inflamed gingival tissues. As for the distribution of the four fimA genotypes of P. gingivalis, type II was most frequently detected in gingival tissues, followed by a co-existent combination of types I and II.
During the maintenance phase, the distribution of most of the microbes in the plaque samples decreased significantly. As for the four fimA genotypes of P. gingivalis, the positive rate of type II decreased markedly, when compared to just before the operation.
These results indicate that P. gingivalis type II fimA is predominant in the gingival tissues of periodontitis patients, suggesting it could play an important role in the onset and/or progression of adult periodontitis. J. Jpn. Soc. Periodontol., 43: 33-42, 2001.

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To study the bone interface around implants and microcirculation, we placed All Dimple System Implants (ADS) in the mandibles of beagle dogs. Superstructures were attached and occlusionpermitted for 9 months. Specimens of microvascular resin casts with bone tissue were prepared and examined using scanning electron microscopy (SEM). We found that tissues in contact with the implant consisted of bone (interface bone) and small masses of fibrous connective tissue. These masses contained a few capillaries having a characteristic structure and configuration. Some lacunae resulting from bone resorption (Howship's lacunae) were seen on the surface of interface bone adjacent to the small masses of fibrous connective tissue. In contrast, Howship's lacunae were not present on the surface of interface bone that lacked blood vessels. The interface as a whole had very few blood vessels.
Behind the interface bone, i.e., on the marrow side, were dense areas of closely intertwined, characteristic capillary networks. Numerous Howship's lacunae were found on the surface of interface bone at this site.
Our results indicate that the thickness of interface bone is controlled on the bone-marrow side. Once formed, the rate of metabolism of interface bone is very low. The inability of tissue to rapidy adapt to environmental changes is suggested by characteristics of microcirculation. J. Jpn.Soc. Periodontol., 43: 43-51, 2001.

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We studied the effects of basic fibroblast growth factor (b-FGF) and carriers on heterogenetic bone formation in subcutaneous tissues of rats using hybrid materials compounded with osteogenetic cells, which were first subcultured cells of rat bone marrow, and 3 types of carrier. We evaluated the optimal concentration of b-FGF needed to differentiate rat bone marrow cells in to osteoblasts. We measured the number of cells, alkaline phosphatase (ALP), and calcium concentration in cultured cells after 0, 2, 4, 6, 8, and 14 days of culture using 2.5 ng/ml and 25 ng/ml b-FGF. In the presence of 2.5 ng/ml b-FGF, ALP activity and calcium concentration were stimulated more than with 25 ng/ml b-FGF.
Hybrid materials compounded with osteogenetic cells and hydroxyapatite (HAP), true bone ceramic (TBC), and BioOss® were cultured for 2 weeks with and/or without 2.5 ng/ml b-FGF. These were incubated in PBS for 3 hours before implantation, and implanted into the subcutaneous tissues of rats. At 5 and 8 weeks after implantation, these samples were retrieved and examined histologically. In the hybrid materials of HAP, we observed better bone formation and maturation in the test group than in controls. Hybrid TBC and BiuOss® materials, however, did not reveal good bone formation in either the test group or controls. Results indicate that hybrid material using of 2.5 ng/ml b-FGF and HAP increases bone forming activity. J. Jpn. Soc. Periodontol., 43: 52-64, 2001.

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We studied the effects of Porphyromonas gingivalis infection and a high-carbohydrate diet (D 2000) feeding on suture-ligation-induced experimental periodontal disease in hamsters. Hamsters underwent suture ligation at lower first molars 3 weeks before of experiments. Sutures were cut and religated. Animals were divided into the following groups: normal diet (CE-2), CE-2 diet plus P. gingivalis infected, D 2000 and D 2000 plus P. gingivalis infected. Alveolar bone loss was the highest in the D 2000 diet plus P. gingivalis infected group, and higher in the CE-2 diet plus P. gingivalis infected group, or the D 2000 feeding group, than the CE-2 feeding group 4 weeks after religation. The number of osteoclasts was also highest in the D 2000 diet plus P. gingivalis infected group, and higher in the CE-2 feeding plus P. gingivalis infected group, or the D 2000 diet group, than the CE-2 diet group during the experiment. Subgingival microflora consisted of Gram-negative rods, Gram-positive cocci, and Gram-positive rods 1 week after religation, but Gram-negative rods predominated 4 weeks after religation in each group. P. gingivalis was recovered 3 to 4% to the total number of bacteria, but recovered 35 to 37% 4 weeks after religation. J. Jpn. Soc. Periodontol., 43: 65-71, 2001.

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We evaluated flap operation (FOP) surgical time per patient and per tooth from April 1, 1996, to March 31, 1999, in the conservative clinic at Tsurumi University Dental Hospital. Subjects number 459-157 men and 302 women with a mean age of 47.4. We analyzed surgical time per patient, per tooth, by tooth type, and by the surgeon's clinical experiences. Only 180 cases-66 men and 114 women with a mean age of 47.4.were analyzed for time per tooth, excluding cases with additional surgery. Surgeons was categorized by experience in periodontal surgery-up to 2, 3-5, and 6 years.
The following results were obtained:
1. Mean FOP surgical time was 96 23 minutes per patient and 34±19 minutes per tooth.
2. Mean FOP surgical time without additional surgery was 31±18 minutes per tooth, FOP with osteoplasty or osteoectomy (OST) 31±18 minutes per tooth, with hemisection or trisection 39±17 minutes per tooth, with extraction 39±20 minutes per tooth, and with guided tissue regeneration (GTR) 44±23 minutes per tooth. Surgical time differed significantly between FOP without additional surgery and GTR, OST and GTR (p<0.05).
3. Mean surgical time of anterior areas was 24±17 minutes per tooth, premolar 35±9 minutes per tooth, and molar 58±124 minutes per tooth. Surgical time differed significantly between anterior and premolar, anterior and molar, and premolar and molar areas (p<0.05)
. 4. No difference was seen in surgical time per tooth for the surgeon's clinical experience. J. Jpn. Soc. Periodontol., 43: 72-79, 2001.

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A case of single facial gingival recession on tooth 31 occuring after orthodontic treatment is described. Factors predisposing. a site to gingival recession are elucidated by evaluating the anatomy of the area including the width of keratinized and attached gingiva, the facial-to-lingual dimension of both soft tissue and the alveolus, and position and angulation of the teeth. If orthodontic treatment improves the position of the tooth within the bony housing, the potential for gingival recession to be reduced in coverage of the exposed root using periodontal plastic surgery is anticipated. The clinical results in this case showed the outcome of orthodontic treatment and periodontal plastic surgery to be almost complete root coverage and esthetic improvement. J. Jpn. Soc. Periodontol., 43: 80-82, 2001.

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