Nihon Shishubyo Gakkai kaishi最新文献

Bone morphogenetic protein (BMP) is known to be a protein which induces new bone at heterotopic sites. Purification of BMP has not been perfected, and obtaining large amounts of BMP is very difficult, so it seems better to use some carrier or frame material for BMP to work effectively. Various kinds of hydroxyapatite (HAP) have been used to repair periodontal osseous defects, but they do not have osteogenetic or osteoinductive properties. If osteoinductive proteins such as BMP could retain their biologic properties after being implanted into living tissue with HAP, it would be an advantage in repairing periodontal osseous defects. In this experiment, we prepared BMP-HAP complex and investigated its osteoinductive activity. BMP was extracted from bovine cortical bones in accordance with the Urist's procedure. The ability of this BMP to stimulate new bone growth was ensured by implantation in the muscle pouch of mice. HAP was synthesized by the wet method. The BMP-HAP complex was implanted in the muscle pouch of mice, and osteoinduction was examined 3, 7, 14, and 21 days after implantation to assess its osteo-inductive ability. New bone formation was studied by roentgenographic and histologic observation. In the BMP-HAP group, new bone formation was seen on the roentgenograms and new cartilage and bone were observed histologically in the tissue surrounding the apatite. In the HAP group, no new cartilage or bone formation was noted.

It seems to be generally agreed that periodontal disease is a local manifestation of a systemic immune response. Interleukin-1 (IL-1), which has multiple biologic activities, is detected in the gingival sulcus fluid of periodontitis sites. Recent investigations have revealed that IL-1 and tumor necrosis factor (TNF) are analogous to osteoclast activating factor and promote bone resorption. These findings have suggested the possibility that IL-1 and TNF may play a significant role in the initiation and development of periodontal disease. However, it remains to be determined whether these cytokines influence periodontal tissue breakdown in periodontitis. To elucidate the mechanisms of tissue breakdown in periodontitis, we examined cytokine production by human periodontitis gingival tissue. Twelve periodontitis patients were included in this study. Control subjects with healthy periodontium consisted of nine individuals. Gingival samples were biopsied from inflamed or healthy gingival tissues. Biopsy specimens were dissected into fragments 3 mm in diameter and plated onto 24 well culture plates with RPMI 1640 medium. IL-1 activity was measured by a growth inhibition assay using melanoma cell line A 375. An enzyme-linked immunosorbent assay (ELIZA) was used for measuring levels of human IL-1 alpha, IL-1 beta. TNF alpha activity was measured by a growth inhibition assay using cell line LM2D6. IL-1 activity was detected in significantly (p less than 0.001) higher levels in culture supernatants from gingival tissues in periodontitis (48.0 +/- 23.3 units/ml) than in control tissues (2.3 +/- 0.6 units/ml), however, levels of IL-1 activity were not associated with periodontal pocket depth or extent of alveolar bone resorption in periodontitis.(ABSTRACT TRUNCATED AT 250 WORDS)

This study was designed to investigate the effect on new attachment formation using a biodegradable membrane as a barrier to the regeneration of periodontal tissue. One-wall wide periodontal osseous defects with exposed root surfaces were prepared in three adult mongrel dogs. After surgical debridement of the periodontal defects, 3 types of biodegradable membranes, [Poly(L-lactic acid); (P-L-LA)] membrane, [Poly(lactic acid-co-glycolic acid); (PLGA)] (81: 19 mole%) membrane and PLGA (50: 50 mole%) membrane, were arranged to cover the denuded root surfaces. Specimen blocks were removed 8 weeks postoperatively for histological evaluation of their effect on the regeneration of periodontal tissue. The results were as follows: 1. Gingival regions containing P-L-LA or PLGA (81: 19 mole%) membranes showed delayed wound healing macroscopically. 2. Almost all P-L-LA membranes were present in the experimental sites failing to be resorbed during the 8-week experimental period. PLGA (81: 19 mole%) membranes were also present but showed with some degree of resorption and fragility, while PLGA (50: 50 mole%) membranes were completely resorbed. 3. This showed that the membranes used in this experiment are possible barriers to the generation of new attachment. It is important to make sure keeping the membrane. 4. There was no relationship between osteogenesis and cementogenesis. It seems that osteogenesis was depressed by membrane shrinkage and the gingival pressure which limited "the regenerative space of bone." 5. Moderate resorption was observed on the root surface, and new cementum was formed at the resorbed surface. 6. Ankylosis was observed between the new cementum and bone at the experimental sites. Newly formed cementum was seen on coronal sections of this area.

The purpose of this study was to evaluate the effect of implants of granular hydroxyapatite (HAP). HAP was implanted into twenty-five vertical bone defects of twenty-one patients as bone graft material. Various clinical and radiographic examinations were performed postoperatively over a twelve month period. Redness and swelling of the gingiva, gingival bleeding, postoperative pain and increased tooth mobility developed transiently, but they all recovered in time. Open wounds and out-flow of HAP disappeared within the first month. After twelve months, mean probing depth decrease was 3.7 mm and clinical attachment gain was 2.5 mm. In all cases there was radiographic evidence of alveolar bone repair. These results suggest that HAP is clinically effective as a bone graft in periodontal therapy.

Scaling and root planing is one of the most fundamental and effective procedures in periodontal therapy. The purpose of this study was to investigate statistically whether clinical or microbiological parameters before treatment are related to changes in probing pocket depth (PD). Two kinds of numerical values represented changes in PD. One was pocket difference (A-B: A; PD before the treatment and B; PD after treatment) and the other was rate of pocket decrase [(A-B)/A x 100]. Twenty four sites in six patients with periodontal pockets deeper than 4 mm were selected for this study. Clinical parameters such as PD, probing attachment level (PAL), gingival crevicular fluid (GCF) volume, gingival bleeding index (GBI) and suppurative index (SI) were recorded at each site. Subgingival plaques sampled at the same site were evaluated by phase contrast microscopy. The results obtained were as follows: 1. Of all the clinical parameters changes in PD were most positively correlated with PD before treatment. 2. The microbiological approach revealed that total bacterial count divided by PD value was more negatively correlated with changes in PD than total bacterial number. It was further, revealed that numbers of rods and motile bacteria were more closely correlated with changes in PD than the counts of bacterial groups. At sites where coccoid cells were relatively dominant, PD tended to decrease readily. Motile bacteria, on the other hand, exhibited just the opposite relationship. These results suggest that periodontal treatment should be more effective in periodontal pockets harboring both smaller numbers of rods and motile bacteria.

The purpose of this study was to evaluate the clinical effect of mace extract and egg-white lysozyme in two brands of chewing gum on gingival condition. Ever since mace extract containing dihydroguaiaretic acid was reported to inhibit the growth of Streptococcus mutans, plans were devised to include it in commercially available chewing gum. Before starting this study, two different types of experimental chewing gum containing mace extract or egg-white lysozyme were made up. A control was also prepared containing neither agent. The periodontal condition of 68 patients with gingivitis was determined based on PMA index (PMA), gingival index (GI), gingival bleeding index (GBI) and plaque scoring system (PSS) and randomly classified into three groups. Each group was instructed to use one or the other of the above type chewing gums after every meal. The results were as follows: 1. No clinical changes were observed in the control group during this study. 2. Gingival inflammation (PMA, GI, GBI) significantly improved as a result of using the experimental gums. 3. Plaque reduction was found only in the mece-extract gum group. 4. No clinical side effects were detected during this study.

Unlabelled: The purpose of this study was to assess the methods of establishing of clinically (experimental) healthy gingiva and to evaluate the status of healthy gingiva in Macaca irus. Three monkeys (2 males and 1 female) were used. After preliminary feeding with hard food for 6 months, plaque control procedures (scrubbing method, modified Stillman method, and flossing) were started. Frequency of plaque removal was three times per week under KETALAR (SANKYO, Co. Tokyo), dissociative anesthesia. We also monitored clinical data.

Results: 1. Forty-nine days later, clinically healthy gingiva were achieved. During this period, no side effects and no tolerance occurred using 12.5 mg/kg of KETALAR, and effective time to perform the procedure was 21.8 minutes. 2. Depending on the plaque control procedure, plaque index (P11), gingival index (GI), and probing depth (PD) were reduced (especially in the first week). However, the level of marginal gingiva (LMG) did not change. 3. Initially and throughout the experiment, PII, GI, PD were lower value in lower jaws, but by the end of experiment there were no differences between the two jaws in PII and PD. However, GI was still lower in the lower jaw at this time. There were no differences between the data for the right and left sides of the jaws at any time throughout the experiment. 4. At the end of experiment, the clinically (experimental) healthy gingiva yielded the following data: PII, 1.7 +/- 0.61; GI, 0.1 +/- 0.60; PD, 1.3 +/- 0.53. No individual differences were found in any of the monkeys at the end of experiment.

The purpose of this study was to evaluate the inflammatory response in dento-gingival units with or without attached gingiva in monkeys. Two different types of dento-gingival units with or without attached gingiva were established in premolar and first molar areas of three monkeys. In the experimental group, a part of the keratinized gingiva was removed with periodontal scissors following mucoperiosteal flap procedure, while in the control group, sham surgery was performed. After the surgery, plaque control was performed by mechanical tooth cleaning procedures three times a week for 3 months. As baseline examinations, width of the keratinized gingiva, probing pocket depth, position of the gingival margin, and the clinical attachment level were recorded and oral photographs were taken. Following these examinations silk ligatures were placed around the neck of the teeth to induce gingival inflammation in both the experimental and control groups. A soft diet which allowed plaque accumulation on the teeth was given during the experimental periods. The clinical examinations were carried out at 0, 1, 2, 3, 5 and 12 weeks and all monkeys were sacrificed for histological examination. The results obtained were as follows: 1. The use of silk ligature and a soft diet produced moderate to severe gingival inflammation in the monkeys. 2. The degree of gingival inflammation was greater in the experimental group which was characterized by the absence of the attached gingiva. 3. Marked marginal tissue recession with an apical shift of the attachment level was found in the gingival units of the experimental group at 12 weeks. 4. Histologically, a distance between the level of notch on the root surface and the most apical position of epithelial cell was greater in the experimental groups at 5 and 12 weeks, compared with the pre-experimental level. 5. The degree of alveolar bone resorption was higher in the experimental group at 5 and 12 weeks. These results suggest that an attached gingival tissue plays a certain role as a barrier against the extension of gingival inflammation.

The morphological characteristics of periodontal tissue in periodontal disease have been interpreted differently by a number of clinical observers. Many have reported that the malposition and functional malocclusion of teeth is injurious to the periodontium. We reported in Part I that a system for evaluating periodontal status was developed for the diagnosis and management of the interproximal area at the initial stage of bone resorption. The patient group consisted of 36 adults, from 21 to 55 years of age. The severity score represented the calculated loss of periodontal support tissues: loss of alveolar bone, evaluated roentgenologically, bone level and pattern in vertical and horizontal form, periodontal pocket and gingival inflammation. Because poor oral hygiene and other factors caused swelling by gingival inflammation, we obtained study specimens from patients with chronic periodontal disease after a few tooth brushing instructions, and scalings during initial therapy in order to detect initial and established pathological changes in periodontal tissue. The purpose of this study was to clarify the relationship between periodontal disease status and morphological diagnostic indicators and different degrees of harmony and disharmony in the lower jaw. In all age groups the average percentage of bone loss and intraosseous defects tended to be higher in the groups categorized as Type III and Type F, and in the area that showed a very deep concave Spee curve to the occlusal plane in Pattern D. We considered that these morphological characteristics might be of secondary importance for diagnosis. Oral local factors were the primary extrinsic factor in the pathogenesis of horizontal and vertical interproximal bone absorption in the area of the premolars and molars.

In order to determine the biocompatibility of glass ceramics which is one of the new biomaterials, in vitro studies were carried out by a cell culture method using four established cell lines. Materials used were glass ceramic disks with a diameter of 3 mm, and polystyrene coverslips of the same size as controls of the growth curve. Cells of each line were inoculated into 24-well multiplates at an appropriate density onto glass ceramic disks, and examined by phase contrast microscopy on the 1st, 3rd, 6th and 8th day. In addition, doubling time and saturation density were calculated from the growth curve. The results obtained were as follows. 1) Phase-contrast microscopy revealed that cells of each line attached to the disk within 24 hours and their numbers increased with time. After 8 days of cultivation, all of them reached confluence. 2) Contact with the glass ceramics did not cause cellular death or degeneration. Furthermore, the cultured cells showed the same morphological features as the control cells. 3) According to the growth curves, doubling time of all cells cultured with glass ceramics was shorter than that of the control cultures. On the other hand, saturation density was reduced to a minimum of 80% of the controls. These findings led to the conclusion that glass ceramic materials do not prevent the growth of cultured cells. According to the above results, glass ceramics possess the characteristics needed for bone grafts and implant materials.