摘要:

A problem associated with probing measurement is that important site‐specific change may be obscured by measurement variability. Furthermore, if many sites are monitored there is an increasing likelihood that any particular “detected change” might be the result of this measurement error. Since error and multiplicity effects would tend to increase mouth‐wise false positive rate, demanding decision thresholds are often set. However, imposition of difficult criteria, increases site‐wise false negative rate and therefore reduces utility in the clinical setting. Evaluation of mean change might sometimes be a useful alternative, but also problematic as a few dramatic site‐level losses can be inconsequential among many stable or improving sites. A strategy is proposed for evaluating probing changes in a single patient, which is based on the statistical evaluation of two attributes of the change distribution. (1) Disease progression is concluded when mean probing loss increases over time, and (2) a clinically relevant asymmetry is concluded when the distribution tail corresponding to loss is skewed. Computerized simulation was used to determine α‐error for tests of mean and skew, for three different distributions of probing change. Actual α‐error was shown to be near nominal levels. Power was estimated as a function of the number and magnitude of sites with probing loss and as a function of whether there was change in both mean and skew or in skew alone. Under most conditions studied, simultaneous tests for skew and mean provided enhanced power relative to a test for loss alone and would appear to offer the clinician an additional statistical context for appraisi

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01256.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

This report describes the succession of putative peri‐implant pathogens in partially dentate monkeys after dental implantation and prosthetic reconstruction. Tooth and implant (6 root‐end form, 4 blade‐vent implants) sites in eight monkeys were monitored microbiologically and clinically during the pre‐implant stage, abutment connection stage, bridge placement stage, and three and six months after the bridge placement stage. Tooth and implant sites were cleaned monthly post‐extraction. Microbiological studies included dark field microscopy, selective and non‐selective culture, and primary phenotypic characterization of culture isolates. After implant surgery, the median proportion of several putative peri‐implant pathogens studied were significantly elevated. Following fixture placement,P. intermediareplacedP. melaninogenicaas the predominant Black Pigmented Anaerobic Bacilli (BPAB) in the mouth. After abutment connection stage, levels ofP. intermedia, A. actinomycetemcomitans, F. nucleatun, Haemophilussp. and spirochetes were significantly elevated at implant and tooth sites. Three months after bridge installations,P. intermediaandA. actinomycetemcomitansremained significantly elevated at implant sites. At six months after bridge installation, levels ofP. intermedia, F. nucleatumandA. actinomycetemcomitansdeclined significantly relative to levels at three months.Porphyromonas sp.and spirochetes were not significantly elevated although their levels correlated with gingival redness.P. intermedia, Porphyromonas sp.and spirochetes levels correlated significantly with probing depth. Correlation was detected betweenP. gingivalisand spirochetes; and betweenA. actinomycetemcomitansandF. nucleatum.Our studies show a transitional increase in levels of several organisms resembling putative pathogens of human peri‐implant infection, associated with implant placements in partially edentulous mouths and supports early prophylactic interventions to contr

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01257.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The unique features of junctional epithelium involve lack of keratinization, limited differentiation and a relatively permeable structure. In order to study the relationship between differentiation and permeability of stratified epithelium a model system was developed. Porcine periodontal ligament epithelial cells were cultured on the polycarbonate nucleopore membrane of the Transwell®two‐compartment culture system. Within 5 days of culture the cells formed a confluent multilayered structure. Subsequently, maturation of the structure and differentiation of surface cells took place. Transmission electron microscopy showed that the cells were arranged into basal and suprabasal layers with sparse desmosomal attachments and wide intercellular spaces resembling the organization of junctional epithelium. The basal cells attached to a subepithelial basal lamina through numerous hemidesmosomes. The cytokeratin profile of the cultured epithelium (K5, 6, 14, 16, 19) resembled that of the cells of junctional epithelium attached to the tooth surface. The older cultures expressed differentiation markers, K4, K13 and involucrin, theraby resembling sulcular epithelium. The epithelial permeability, measured by diffusion of phenol red, radioactive dextran or methionine tracers, and as transepithelial electrical resistance, decreased with the increased cell number and maturation of the cultures. The new model provides an organotypic culture system which allows to control differentiation of a multilayered periodontal epithelium. It thus may serve as a valuable new tool for studies on the permeability and behaviour of periodontal epithelium under the influence of exogenous and endogenous facto

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01258.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Human gingiva was stained with cupromeronic blue according to Scott's critical electrolyte concentration technique in order to localize glycosaminoglycans (GAG) in the electron microscope. Identification was performed by digestion with chondroitinase AC, ABC and heparinase. The GAG were localized in three compartments of the connective tissue: the supra‐alveolar fiber apparatus, the loose connective tissue and the basement membranes. In the supra‐alveolar fiber apparatus, consisting mainly of densely packed parallel collagen fibrils, dermatan sulfate GAG are regularly attached to the d‐band of the collagen fibrils. The precipitates (6–7 nm in diamter) aggregate to thicker precipitates (up to 16 nm), thus possibly providing stability to the fiber system. In the loose connective tissue with sparse collagen fibrils dermatan and chondroitin sulfate GAG form very large precipitates (up to 30 nm in diameter and 400 nm length) which interconnect the few collagen fibrils. The basement membranes of the epithelium and capillary endothelium contain heparan sulfate GAG as fine precipitates (4–6 nm in diameter) which form a meshwork. These findings are consistent with the Scott model (1) for the interactions among glycans and glycans and collagen fibrils in connectiv

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01259.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

When neutrophils are incubated with bacterial lipopolysaccharide (LPS), they become primed for enhanced release of superoxide anion (O2−) in response to stimulation by FMLP. We investigated the human neutrophil‐priming activity of LPS from the periodontal pathogens,Porphyromonas gingivalis (Pg),Prevotella intermedia (Pi) and Actinobacillus actinomycetemcomitans (Aa)in comparison with that of LPS fromEscherichia coli (E. coli). The optimum conditions for LPS to prime neutrophils were assessed for every LPS and found to be as follows: Neutrophils were incubated with LPS in the presence of 10% heat‐inactivated plasma and 1 mM EDTA at 37°C for 30 min and then stimulated with 1 μM FMLP at 37°C for 7 min. Under these conditions, half‐maximum priming was observed at 6.2 ng/mlPg‐LPS, 45 ng/mlPi‐LPS, 1.5 ng/mlAa‐LPS and 1.5 ng/ ml E.coli‐LPS. The priming activity of each LPS was neutralized by polymyxin B. Anti‐CD14 monoclonal antibody inhibited priming by all LPS. The priming byAa‐LPS and E.coli‐LPS was inhibited by LA‐14‐PP, a synthetic lipid A precursor IVA, but that byPg‐LPS andPi‐LPS was not. Priming by tumor necrosis factor alpha was not affected by polymyxin B, anti‐CD14 antibody or LA‐14‐PP. Gelation ofLimulusamebocyte lysate occured at 10 pg/mlPg‐LPS, 30 pg/mlPi‐LPS, 3 pg/mlAa‐LPS and 3 pg/ml E.coli‐LPS. Thus LPS from different periodontal pathogens primed neutrophils with different efficacy. The difference in the sensitivity to LA‐14‐PP among the four LPS tested raises the possibility that the mechanism of host response toPg‐LPS orPi

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01260.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Studies were performed to investigate the effect of microbial culture supernatants of periodontal pathogens on the metabolism of radiolabelled testosterone in the presence or absence of human gingival fibroblasts. Subgingival plaque samples were obtained on paper points from 3 sites with probing depth values of 6–8 mm. Samples were incubated with 14C‐testosterone for 24 h in brain heart infusion (BHI) broth. Similar incubations were also carried out with strains ofA. actinomycetemcomitans, P. IntermediusandP. gingivalisto study the metabolism of radiolabelled testosterone by these periodontal pathogens. At the end of a 24 h incubation period with fibroblasts and supernatants or sonicates, the radioactive metabolites were extracted with ethyl acetate, evaporated and subjected to thin layer chromatography. The separated metabolites were quantified by scanning the radioactive plates using a Berthold linear analyser. When three sub‐gingival plaque samples were incubated with radiolabelled testosterone there were 50‐fold. 10–12‐fold and 15–17‐fold increases in 5α‐dihydrotestosterone (DHT) synthesis over 4‐androstenedione production in these mixed microbial cultures. The two strains ofP. intermediusproduced 3‐ and 20‐fold increases in 4‐androstenedione production and DHT synthesis respectively. Both strains ofA. actinomycetemcomitansandP. gingivalisshowed 3–4‐fold and 12–28‐fold increases respectively in 4‐androstenedione synthesis over that of DHT. Culture supernatants ofP. intermediusandP. gingivaliscaused 3‐fold and 2‐fold increases in DHT synthesis by fibroblasts over controls. There was little change in the case of the third pathogen. Since DHT has implications on matrix synthesis by fibroblasts in the environment of plaque associated inflammatory periodontal disease, bacterial metabolism and the effect of bacterial supernatants on human gingival fibroblasts can inf

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01261.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The plasminogen activator (PA)‐plasmin system is implicated in the degradation of the extracellular matrix in inflammation through activation of metalloproteases and prekallikrein. We examined the activation of the PA‐plasmin system in human gingival fibroblast cells (Gin‐1 cells) following treatment with lipopolysaccharide (LPS) fromCampylobacter rectus, which is frequently detected at sites of periodontal disease. TheC. rectusLPS stimulated the plasmin activity in the conditioned medium of Gin‐1 cells in a time‐and dose‐dependent manner, andC. rectusLPS also stimulated the PA activity in the conditioned medium. The PA produced by Gin‐1 cells was determined to be urokinase PA (uPA), as prein‐cubation of Gin‐1 conditioned medium with anti‐uPA antiserum completely in‐hibited the PA activity while that with anti‐tPA antiserum had no inhibitory effect. The concentration of PA inhibitor‐1 (PAI‐1) in the conditioned medium was decreased by the addition ofC. rectusLPS. Therefore, the enhancement of plasmin activity in the conditioned medium was dependent on increased uPA activity via the decrease of the PAI‐1 level of Gin‐1 cells treated withC. rectusLPS. Furthermore, the conditioned medium of Gin‐1 cells treated withC. rectusLPS showed significantly increased kallikrein activity, indicating the conversion of prekallikrein to kallikrein, which converts kininogen into kinin. These findings suggest thatC. rectusLPS is a potent stimulator of inflammation of gingival tissue which acts through sti

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01262.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

It has been shown that the vesicles produced byPorphyromonas gingivalisunder certain growth conditions contribute to its pathogenicity. In this study, we demonstrate the cytotoxic effect of the vesicles using two methods: on quantitative (the colorimetric cytotoxicity test using sulforhodamine B) and the other qualitative (flow cytometry).

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01263.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Two methods for the determination of sample volumes between 0.2 and 0.6 μl were compared by preparing standard curves for volumes over this range. The first method used a Periotron and the second the sample mass. A linear model was fitted and 95% confidence limits for volumes estimated by each method were calculated. This showed that use of either the maximum Periotron reading or the sample mass allowed estimation of volumes to within ±0.056 mUl and ±0.047 mUl respectively. It is proposed that measurement of sample mass provides a simple and accurate method to determine sample volume when analysing drug concentrations at specific sites in the oral cavi

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01264.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb01265.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY