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Biomedical subjects

M Minabe

Publications and source records attributed to M Minabe.

At least 19 recordsLinked to original sources
PubMed2001

Clinical significance of antibiotic therapy in guided tissue regeneration with a resorbable membrane.

This study was designed to evaluate the clinical significance of antibiotic therapy combined with guided tissue regeneration (GTR) therapy with a collagen membrane. The subjects were 20 adults diagnosed with periodontitis (20 intrabony periodontal defects). Ten patients were treated with GTR alone (control group) and the other 10 patients were treated with a combination of GTR and antibiotics (antibiotic group). In the antibiotic group, minocycline ointment was applied locally before GTR therapy, and doxycycline and amoxyline were systemically administered after GTR therapy. Clinical manifestations, the presence or absence of exposed membrane, and microbiological findings were assessed 1 month before, immediately after, and 2 weeks, 6 weeks, and 3 months after GTR therapy. The results showed no significant differences in reduction of probing depth, probing attachment gain (PAG), or the ratio of PAG to intraoperative depth of the intrabony defect (vertical relative attachment gain) between the antibiotic group and the control group before and 3 months after GTR therapy. A DNA probe test and specific enzymatic activity test revealed no significant differences in the improvement and the rate of bacterial negativity before, and 6 weeks and 3 months after, GTR therapy. These findings indicate that antibiotic therapy is not clinically beneficial when combined with GTR therapy with a collagen membrane.

Absorbable Implants↗
PubMed2000

Intra-pocket antibiotic therapy using resorbable and non-resorbable slow-release devices containing tetracycline.

Since it is a disease mainly caused by plaque--an aggregate of various bacteria--periodontal disease can be considered a local infection. Thus, it has seemed reasonable to utilize antibiotics to suppress the intrapocket bacteria, specifically or nonspecifically. When antibiotics are administered orally, however, massive doses over a prolonged period of time are needed to attain a therapeutic effect. This increases the risk of adverse reactions as well as developing resistant strains of bacteria. To overcome these problems, local drug delivery systems (LDDS) were devised to combat the local infection. However, the intrapocket antibiotic delivery systems have yet to be fully evaluated for clinical effectiveness; to prove the therapeutic effectiveness of locally administered antibiotics, the drug must reach the base of the periodontal pocket and the effective concentration of the antibiotic against the pathogenic bacteria must be maintained for a long time. This concise review presents with figures, tables, and a comprehensive list of references the many studies which have used the various tetracyclines as LDDS to treat periodontal disease.

Administration, Topical↗
PubMed1994

The effect of root conditioning with minocycline HCl in removing endotoxin from the roots of periodontally-involved teeth.

Noting the acid-conditioning effect of minocycline on the root surface, we investigated the ability of minocycline to remove endotoxin on untreated, diseased cementum in vitro. Root surface specimens affected by periodontal disease were immersed in minocycline solution (10 mg/ml, 50 micrograms/ml, and 5 micrograms/ml) for 10 minutes, 1 day, 3 days, and 7 days, and endotoxin eluted was determined by the limulus amoebocyte lysate (LAL) assay. Specimens serving as controls were treated by immersion in pyrogen-free water, agitation, polishing, or exposure to citric acid (pH 1.0) for 3 minutes. When the period of immersion was the same, the root treatment with minocycline (10 mg/ml) yielded a significantly higher rate of neutralization of endotoxin than that with a 5 micrograms/ml or 50 micrograms/ml solution. However, the detoxifying effect of this method was less adequate than that of polishing or treatment with citric acid solution. There was variability in the effects of polishing among the teeth tested. To obtain the expected effect of the root treatment with minocycline solution; i.e., removal of the endotoxin, the combining of minocycline with a mechanical root preparation, such as polishing or root planing, seems to be effective.

Analysis of Variance↗
PubMed1991

Therapeutic effects of combined treatment using tetracycline-immobilized collagen film and root planing in periodontal furcation pockets.

46 upper and lower molars with furcation grade II involvement were selected from 16 patients with periodontal disease. The teeth were randomly allocated to the following groups according to treatment; (1) 4 consecutive administrations of tetracycline-immobilized cross-linked collagen film (TC film) at intervals of 1 week (TC group); (2) 1 root planing treatment (RP group); (3) combination treatment (TC + RP group); (4) no treatment (control group). The therapeutic effects of each treatment were compared both clinically and microbiologically. Records of plaque index, gingival index, bleeding on probing, probing depth, probing attachment level and microscopic counts were obtained at 0, 4, 6 and 8 weeks. The results showed marked decreases in probing depth and density of micro-organisms in both the RP and TC + RP groups. In particular, the TC + RP group was characterized by a decreased rate of bleeding on pocket probing and an increased probing attachment gain. The above findings demonstrated that root planning is effective in the treatment of furcation involvement and that the effects are enhanced by the local administration of TC films.

Collagen↗
PubMed1991

A critical review of the biologic rationale for guided tissue regeneration.

This review discusses the rationale for using guided tissue regeneration therapy. The review not only attempts to clarify the concept of selective tissue regeneration using non-resorbable and resorbable barriers, but to discuss differences in healing events after treatment with the two types of barriers together with their significance in periodontal therapy. At present, barrier membranes have potential clinical use in promoting periodontal tissue regeneration if patients to be so treated are selected appropriately. Research is still necessary to determine the critical period for guiding the ingrowth of new attachment forming cells and also to further clarify the concept of GTR involving the "wrong cell type" which inhibits periodontal tissue regeneration.

Animals↗
PubMed1989

Clinical effects of local application of collagen film-immobilized tetracycline.

Tetracycline-containing cross-linked collagen film (TC film), or tetracycline-free placebo film, were locally applied 4 times, at 1-week intervals, to 33 teeth with periodontal pockets larger than 4 mm, in 11 patients with periodontal disease. The clinical and microbiological effects are summarized, as follows. In the group treated with the TC film, (1) the clinical indices were significantly decreased at the 4th and 7th weeks in comparison with those at the beginning of treatment. In particular, this group showed a significant decrease in the incidence of bleeding as compared with the placebo group at the 4th week. (2) Total counts of bacteria in the periodontal pockets showed an obvious tendency to decrease with time. The proportion of black-pigmented bacteroides was significantly decreased at the 4th and 7th weeks when compared with the pretreatment value. The extent of decrease in the proportion of spirochetes at both the 4th and 7th weeks was significant compared with the placebo group and the pretreatment value.

Bacteroides↗
PubMed1989

Effects of atelocollagen on the wound healing reaction following palatal gingivectomy in rats.

Collagen membrane preparations have been manufactured with the aim of enhancing wound healing following periodontal surgery. After cross-linking by various processing methods (with ultraviolet radiation or hexamethylenediisocyanate) and to various extents, atelocollagen membranes were applied into dissection sites within palatal gingival tissue. Applied atelocollagen was histopathologically compared with applied lyophilized porcine dermis (LPD) and controls in rats, with regard to the time course of healing. The atelocollagen-applied group showed more satisfactory regeneration of the epithelium and connective tissue in an artificially created gingival defect than did the control group or the LPD-applied group. Epithelial downgrowth along the root surface was significantly suppressed by the use of atelocollagen. In addition, the post-operative inflammatory reaction and foreign body giant cell reaction subsided rapidly after surgery in the atelocollgen-applied group. Our results show that the use of atelocollagen membrane in periodontal wounds should be the method of choice.

Animals↗
PubMed1989

Different cross-linked types of collagen implanted in rat palatal gingiva.

Collagen membrane preparations were manufactured with the aim of enhancing wound healing following periodontal surgery. After crosslinking by various processing methods (with ultraviolet and hexamethylenediisocyanate) and to various extents, two types of collagen (atelocollagen and tendon collagen) were implanted into a dissection site within palatal gingival tissue. The time course of healing responses was investigated histologically. Collagen implantation was found to accelerate fibrous connective tissue attachment to the root surface and inhibit apical migration of the junctional epithelium. Cross-linked atelocollagen was superior in biocompatibility to the other collagen membranes studied.

Animals↗
PubMed1989

Subgingival administration of tetracycline on a collagen film.

The purpose of this study was to evaluate the duration of therapeutic effect after administration of the collagen film immobilized tetracycline (TC film). TC film or tetracycline non-immobilized placebo film was applied one time to the periodontal pocket (greater than or equal to 4 mm) of five periodontitis patients (20 teeth). The clinical and microbiological effects are summarized as follows: The group that received TC film continued to show significantly low values for bleeding upon probing the pocket depth for 3 and 4 weeks, respectively, after administration, but there was no significant difference in the plaque index or gingival index when compared with the group that received a placebo film. In the TC film group, the density of microorganisms and the proportion of motile rods and spirochetes were also significantly decreased 3 weeks after administration. These findings suggest that topically administered TC film remains both clinically and bacteriologically effective for 2 to 3 weeks.

Administration, Topical↗
PubMed1989

Application of a local drug delivery system to periodontal therapy: I. Development of collagen preparations with immobilized tetracycline.

For the purpose of applying a local drug delivery system to periodontal therapy, atelocollagen preparations with immobilized tetracycline (TC) were prepared by modifying the form of the collagen, the concentration of the immobilized TC, and the time of the cross-link process with glutaraldehyde. The course of the TC release from the collagen preparations into an aqueous solution was determined in relation to time. The preparations were also inserted into periodontal pockets, and the amount of TC remaining in the pocket was determined daily. The results obtained were as follows: 1) The degree of drug release could be controlled to some extent by adjusting the TC concentration and the time of the cross-link process; and 2) an amount of TC exceeding the effective dose in the gingival crevicular fluid was present in the periodontal pocket even 10 days after the insertion of TC fixed in the cross-linked processed collagen film in the periodontal pockets.

Bacteria↗
PubMed1989

The effect of various concentrations of collagen barrier on periodontal wound healing.

Collagen membrane preparations were manufactured with the aim of enhancing wound healing following periodontal surgery. In order to clarify effects of different concentrations of collagen on wound healing, a basic study was performed. Solutions containing 0.5%, 1.0%, and 1.3% atelocollagen were treated with hexamethylenediisocyanate (HMDIC) for cross-linking, and collagen membranes were prepared with each solution. Periodontal flap surgery was performed on the palatal gingiva beside the maxillary first molar teeth in rats. The root surface of the tooth was exposed and curretted. Then, a piece of atelocollagen membrane was implanted. The healing of the wound was studied histologically and the following findings were made. (1) Apical migration of the junctional epithelium occurred within 2 weeks postoperatively. (2) The implantation of atelocollagen membrane significantly reduced the apical migration. (3) The apical migration of the epithelium did not vary with collagen concentration.

Animals↗
PubMed1989

[Application of beta-tricalcium phosphate to periodontal therapy. Part 1. Fundamental studies and biological tests of beta-TCP prepared by mechanochemical method].

Physical, chemical, biological and implant tests on calcium phosphate prepared by the mechanochemical method with wet milling were performed to determine their applicability for periodontal therapy. 1. Materials synthesized by the new method had a stoichiometric ratio of Ca/P = 1.50 and a density of 3.70 g/cm3 and coincided with the standard pattern of beta-TCP (ASTM Card) very well. 2. The surface structure of dense type sintered at 1,100 degrees C showed fewer fine pores than the dense type sintered at 1,050 degrees C. The surface structure of the porous type sintered at 1,050 degrees C showed finer pores, except for a continuous large pore than the porous type sintered at 1,000 degrees C. 3. Specific conductivity tests should higher solubilities of the porous type than of the dense type in pure water, and of materials sintered at low temperature than at high temperature. 4. Cytotoxicity studies with V-79 cells showed no significant differences from the controls, and other biological tests revealed no abnormalities. 5. At three and six weeks after implantation in muscles, all of beta-TCP was enclosed with collagen fiber. The porous type of beta-TCP was almost completely fused to cranical bone in rabbits three weeks after implantation. The dense type of beta-TCP was completely fused to cranical bone six weeks after implantation. From these results, it can be concluded that beta-TCP prepared by the new method is of high purity and biocompatibility. Consequently beta-TCP is expected to be effective in clinical use.

Biocompatible Materials↗
PubMed1989

[Application of local drug delivery system to periodontal therapy. 4. Comparison of the therapeutic effects of administration of a TC film or root debridement on human periodontal disease].

In 8 patients with periodontal diseases under good supragingival plaque control, 22 test teeth each having a pocket not more than 4 mm deep were treated respectively with 3 consecutive administrations of tetracycline immobilized cross-linked collagen film (TC film) at intervals of 1 week, with onceroot planing and with both of these. The therapeutic effects were compared both clinically and micro biologically. The results revealed improvements in clinical symptoms such as reduction in the depth of the pocket, bleeding on pocket probing and the like for each treatment group in 6-12 weeks. The second and third groups also showed remarked gingival recession. Further more, the density of intrapocket microorganisms showed a remarked decrease up to the 8th week for each treatment group and the population of spirochetes showed a decrease up to the 6th week for the first treatment group and up to the 8th-12th week for the second and third treatment group. The results show that both local application of the TC film and root planing are effective in periodontal treatment, but not the combined treatment.

Collagen↗
PubMed1989

[Application of local drug delivery system to periodontal therapy. 5. Clinical and microbiological effects of TC film application in furcation involvements].

Two molars having furcation grade II involvements were selected from each of six patients with periodontal diseases. One molar received a local application of tetracycline immobilized cross-liked collagen film four times at one-week intervals (TC film-treated group) and the other received no treatment (non-treated group). The clinical and microbiological effects were, as follows, 1. Throughout the experimental period, no significant differences in pocket depth, attachment level, bleeding on pocket probing, periotron unit, gingival index and plaque index were noted between the TC film-treated group and the non-treated group. 2. One week after TC-film application, the treated group showed significant decreases in the density of microorganisms and the proportion of spirochetes compared with the non-treated group. The results revealed the insufficient effectiveness of the local application of TC film by itself for the treatment of teeth having furcation grade II involvements.

Collagen↗