The effects of amlodipine, a third generation dihydropyridine calcium antagonist, on human gingival fibroblasts were investigated in vitro. The growth of fibroblastsobtained from an intact donor was inhibited by amlodipine in a concentration-dependent manner. Amlodipine reduced the growth rate, DNA synthesis and oxygen consumption of the fibroblasts. Fuotherarore, the addition of amlodipine in culture media changed the spindle-like appearance of adherent fibeoblasts to round shapes, caused cell detachment from the culture plate and decreased cell viability. In adclition, the presence of amlodipine prevented the fibroblasts floating in suspension from attaching to the culture plate and severely decreased the viable cell rate. These results indicate that amlodipine has no profitable action, but shows inhibitory effect on human gingival fibroblast in vitro. This finding suggests that gingival hyperplasia induced by amlodipine is not ascribed to the direct action of amlodipine on gingival fibroblasts. J. Jpn. Soc. Periodontol., 41: 371-379, 1999.

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This study was designed to examine the aging effect on bone formation induced by recombinant human BMP-2 (rhBMP-2) combined with polylactate-polyglycolate-copolymer/gelatine sponge complexes (PGS) at palatal subperiosteal sites (N=72) in 36 Wister strain male rats, at 10 weeks, 30 weeks and 70 weeks of age. The rats at each age were divided into three groups: no implant (CN), PGS implant alone (CI), rhBMP-2 combined with PGS implant (E). The rats were killed at 6 weeks after implantation, and histopathologic observation and histometric evaluation were performed. In histopathologic observation, new bone formation was observed in every group at each age, and the new bone was almost completely continuous with the original palatal bone. In histometric evaluation, the new bone volume was largest in 10-week-old rats and gradually decreased by age in each group. At each age, the new bone volume in group E was significantly larger than that of groups CN and CI. These results indicate that rhBMP-2 combined with PGS induces new bone formation that is continuous with original bone not only in young rats but also in old rats which have less bone formation activity, although the volume of the new bone at the BMP-implant site shows gradual decrease by aging. J. Jpn. Soc. Periodontol., 41: 380-391, 1999.

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The purposes of this study were to evaluate the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) on induction and regeneration of cementum, periodontal ligament and alveolar bone, and on associated root resorption and ankylosis. In dogs, fenestration bony defects of critical size (5×5 mm) were surgically produced and rhBMP-2 (0.4. μg/mm³) in combination with polylactic acid polyglycolic acid copolymer and gelatin sponge complex (PGS) carrier were implanted on the planed root surface. Also the cementum and periodontal ligament surrounding the defect were damaged with an electric knife. In the control group, the same carrier material without rhBMP-2 was implanted in the same manner. The observation periods were 13-16 weeks and availability was clinically, histopathologically and histometrically analyzed.
In the control group, 2 sites were inflamed at 4 weeks after surgery. In the rhBMP-2 treated group, good progress was observed after the operation. In histometric evaluation, the rate of alveolar bone regeneration was significantly his her in the rhBMP-2 treated group (97%, cont. 81%, p<0.05). However the rate of cementum regeneration was not significantly higher in rhBMP-2 sites (54%) than in control sites (44%). In root resorption, only surface resorption was observed and the root resorption rate was 29% in rhBMP-2 sites and 41% in control sites. Ankylosis was not observed in any site.
Thus, the implantation of rhBMP-2/PGS on the planed root surface clearly increases alveolar bone and periodontal ligament regeneration without ankylosis, and may increase cementum regeneration. J. Jpn. Soc. Periodontol., 41: 392-408, 1999.

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The aim of this study was to evaluate effects of root planing and removal of inflammatory granulation tissue on periodontal tissue on guided tissue regenaration (GTR) using expanded polytetrafluoroethylene (ePTFE) membrane (Gore-Tex® periodontal material). The gingival flaps were elevated and the buccal bone was reduced to approximately 5 mm from alveolar crest on five mongrel adult dogs. The experimental region was divided into four groups and treated by the root planing and/or the removal of inflammatory granulation tissue. A notch was marked at the level of the crest of the remaining alveolar bone. After the root surfaces of the defects were conditioned with 10% Acromycin, the membranes were placed. The gingival flaps were repositioned and sutured. After 4 weeks, the membranes were removed. At the 24 weeks after surgery, the dogs were sacrificed. The results indicated that the amount of periodontal tissue regeneration in the group of only root planing was more than that in the group of only removal of inflammatory granulation tissue. And no significant difference of the amount of periodontal tissue regeneration was observed between group of both the root planing and the removal of inflammatory granulation tissue and group of only root planing. These results suggested that root planing than removal of inflammatory granulation tissue were more important for periodontal tissue regeneration on GTR. J. Jpn. Soc. Periodontol., 41: 409-416, 1999.

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To understand the interaction between neutrophils and Fusobacterium nucleatum, a periodontopathic bacteria, we investigated the effects of bacterial surface materials on activation of neutrophil functions in vitro.
Heptylthioglucoside extract (HE) and a cell envelope fraction (CE) were prepared from F. nucleatum ATCC 25586. Human peripheral neutrophils were stimulated with HE or CE in the absence of serum, and superoxide anion released from the cells was measured by chemiluminescence (CL) assay. The CLstimulation activity of HE was much higher than that of CE, and was not inhibited by proteinase K. Therefore, we obtained CL-inducing surface materials (CSM) from proteinase K-digested HE by anion exchange and gel permeation column chromatography. Analysis by SDS-polyacrylamide gel electrophoresis showed that CSM contained some polypeptides, lipopolysaccharide (LPS) and other polysaccharide materials. Although F. nucleatum LPS exhibited no neutrophil CL stimulation, CSM stimulation was inhibited by addition of polymyxin B and by pretreatment of heat or phenol. These results demonstrated that neutrophil CL was mediated by LPS and proteinaceous factors of the bacterial cell surface. Furthermore, we observed that CSM stimulated the release of interleukin-8 (IL-8) from neutrophils in the culture medium using enzyme-linked immunosorbent assay and exhibited neutrophil migration by Boyden method. The induction of IL-8 and neufrophil migration were not inhibited by addition of polymyxin B or by heat treatment of CSM. After CSM had been treated with phenol, IL-8-releasing activity was present in the phenol-extractable fraction and migration-stimulating activity was detected in the water-soluble fraction. These results indicate that the surface materials of F. nucleatum stimulate the activation and the migration of human neutrophils and are involved in the initiation and progression of periodontal tissue inflammation. J. Jpn. Soc. Periodontol., 41: 417-428, 1999.

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The aim of this study was to obtain the fundamental data to develop an algorithm for the recognition of the gingival shape. Fifty-one frontal views of upper and lower incisors (male 14, female 13 ; upper 25, lower 26) were used. All of the pictures were taken using a digital camera with a stroboscope (Kodak DC 420 and Nikon Medical Nikkor 120 mm F 4). They were saved as Tag Image File Format (TIFF) files with 2²⁴ color depth (Red 2⁸, Green 2⁸, Blue 2⁸) using the Photo Shop 3.0 J® (Image Processing Software; Adobe Systems Inc., USA). The size of each image was 1, 524×1, 012 pixels, and 4.5 MB in memory size. We used IPLab Spectrum™ (Image Processing Programing Software ; Signal Analytics Corporation, USA) for making the program. A histogram of each image was analyzed on RGB, HSV, YIQ and RsGsBs color coordinate system. These histograms were in the range of [0, 255]. The Gs-histogram peak near the 65-gray level was most valid of the 12 colors to separate the soft tissue and tooth areas. For automatic thresholding of vacant spaces, the correlation coefficient and the function between the modal values (MO) and the vacant thresholding values (VT) were calculated as follows using Red images : VT=0.527×MO+ 16.05, r=0.763 (p<0.0001). Thresholding with calculated VT using MO mistakenly identified the low brightness areas of the soft tissue as vacant space. We plan to develop an algorithm for automatic recognition of the shape and redness of the interdental papilla. J. Jpn. Soc. Periodontol., 41: 429-435, 1999.

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The acute phase of periodontitis (periodontal abscess) has been thought to be related with rapid periodontal breakdown. The effects of topical application of 2% minocycline hydrochloride ointment into the periodontal pockets in the acute phase of periodontitis were studied. One hundred patients with acute periodontitis including periodontal abscesses participated in this study. Patients were assigned randomly to either the test or control groups and compared by a blind method. Acute periodontitis including the periodontal abscesses were treated by subgingival irrigation plus application of 2% minocycline hydrochloride (test group) or by subgingival irrigation only (control group), and examined clinically at baseline, third and seventh days. Microbiological samples were also collected at the baseline and seventh days. The study was performed based on the standards of Good Clinical Practice (GCP). Though the clinical improvements were observed in both groups after treatment, the test group had better results than the control group. The test group showed better improvement of probing depth and attachment level than the control group. On bacteriological examination, both groups exhibited reduction of colony-forming units (CFU) of subgingival plaque bacteria, and higher reduction was observed in the test group. In a comparison of periodontopathic bacteria detection, the frequencies of detection of Bacteroides forsythus, Porphyrornonas gingivalis and Treponema denticola were reduced only in the test group. These results indicate that the topical application of 2% minocycline hydrochloride ointment was effective for treatment of the acute phase of periodontitis. J. Jpn. Soc. Periodontol., 41 : 436-449, 1999.

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The effect of toothpaste containing a bacteria adsorbing agent on plaque removal was evaluated under a double-blind cross-over experimental design as compared with an inactive control. The subjects were 80 dentate volunteers of dental students (42 males, 38 females, age: 18 to 42 years, average 21.7 years). The representative 6 teeth (upper right 1^st molar, lateral left 1^st premolar, lower right 1^st premolar, left lateral 1^st molar) were examined for plaque removal. The height of plaque from the cervical gingival margin of the tooth was measured. Each subject was allocated a toothpaste according to predetermined randomization. During the 1St week and the 5th the week (washout week), the subjects toothbrushed with the same assigned toothbrushes and toothpastes. The subjects were instructed to brush with placebo or test toothpaste during the 1^st and the 2^nd 4-week study period. The subjects brushed with their ordinary brushing method, and refrained from using any other oral hygiene products during the 10-week experimental period. Scoring of plaque was performed at the end of each 4-week study period. Also, at the beginning of each 1^st week, one-shot plaque removal was evaluated for each toothpaste. Moreover, the toothpastes' side effects on oral soft tissues, teeth, restorations and change in oral bacterial flora were observed, using phase contrast microscopy.
The following results were obtained: 1) Toothbrushing with the test toothpaste was statistically more effective (p<0.05) for plaque removal than that with the placebo. 2) No side effects were observed with either toothpaste; 3) Effectiveness for plaque control was obtained with the test toothpaste containing a bacteria adsorbing agent. J. Jpn. Soc. Periodontol., 41: 450-460, 1999.

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The present study aimed to investigate long-term responses to periodontal therapies of periodontitis patients with high levels of serum IgG antibody titers to both A. actinomycetemcomitans and P. gingivalis before treatment. Sixteen patients showing high titers to both pathogens (AaPg group) and 36 patients with high serum antibody responses to P. gingivalis only (Pg group) before treatment participated. Initial alveolar bone-loss ratio per tooth was measured in each patient. Eleven and 13 patients in the AaPg and Pg groups, respectively, were followed up for more than 3 years. Teeth extracted average and the teeth ratio average with severe disease progression per year were determined in all cases. Also the patients were assigned as well maintained (WM), downhill (D), and extreme downhill (ED) cases according to their teeth extracted average. The AaPg group showed significantly higher initial bone-loss ratio (44.6%) as compared to the Pg group (33.2%). In the cases treated for more than 3 years, significantly higher initial bone loss (44.2%), teeth extracted average (0.96), and teeth ratio average with disease progression (4.0%) were observed in the AaPg group than in the Pg group (31.0%, 0.17, 1.0%, respectively). Seven of 11 in the AaPg group were assigned as ED cases, whereas 9 of 13 among the Pg group were categorized as WM cases. Patients showing a mean initial bone loss between 20% and 50% were selected for further comparison between the 2 groups. In such comparison, the AaPg group demonstrated higher in extracted teeth values and in disease progression ratio than the Pg group (0.67 vs 0.14, 2.5% vs 1.1%, respectively) with no significant difference, and 4 of 6 in the AaPg group were categorized as D or ED cases, while 7 of 9 in the Pg group were assigned as WN cases. These results indicate that patients showing high serum antibody titers to the above mentioned pathogens demonstrate severe bone loss and poor responses to periodontal therapies. Therefore, the measurement of serum antibody titers may be a useful tool for diagnosis and/or prognosis of periodontitis. J. Jpn. Soc. Periodontol., 41: 461-468, 1999.

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