摘要:

Digital subtraction radiography (DSR) has been shown to be a sensitive and specific method for the detection of small bony changes in periodontitis. The purpose of this study was to perform a multicenter validation of the DSR in human subjects. Seventeen subjects were enrolled at 3 centers. Feather‐edged hydroxyapatite chips (approximately 1,7 and 10 mg) were used to simulate osseous lesions. Bilateral radiographs were taken with and without chips. Geometry was standardized using a cephalostat and the order of radiographs was determined using a randomization plan. Radiographs were subtracted, lesions isolated, and quantified at a single center without knowledge of the randomization code or location of the chips used in each subject. The overall sensitivity and specificity in detecting 1 mg changes was 87.8% and 100%, respectively. Sensitivity and specificity in detecting 7 mg and 10 mg chips was 100%. A strong linear relationship between actual lesion mass and calculated mass was observed (R2=0.94, slope=0.98, p<0.0001). No significant differences were observed by center. These data indicate that the DSR is a valid technique for the assessment of alveolar bone changes in multicenter trial

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00478.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

A new method, digital image ratio (DIR), has been developed for directly measuring changes in alveolar bone. The image on the computer monitor represents the relative mass change between two radiographs. Fourier filtering is used to reduce noise artefacts. This method is validated through an experiment with a step wedge. DIR needs only a preliminary calibration of the experimental conditions of operation and avoids tedious calibrations for each measurement as in the case of digital image substraction. Low‐voltage X‐ray techniques are suggested for long‐term quantitative studies of patients to minimize irradiation

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00479.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00480.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Guided tissue regeneration is a clinical procedure used to restore mineralized tissue that has been lost to periodontal disease or after tooth extraction. The procedure makes use of Gore‐tex® membranes or Gore‐tex® augmentation membranes (GTAM) to prevent migration of keratinocytes and gingival fibroblasts into healing wounds. To begin to characterize the regenerative cells associated with these membranes, human cells have been rescued from membranes retrieved after bone‐inductive procedures. Cell lines were established from tissue adherent to Gore‐tex® membranes used to regenerate bone around periodontally compromised teeth, and from tissue adherent to GTAM used in edentulous ridge augmentation procedures or in conjunction with implant placement. Cell lines were screened for mineralized nodule formationin vitroprior to their subsequent analysis. All but one of the lines selected for this study formed mineralized nodulesin vitrowith cells from GTAM tending to form modules more quickly than cells from Gore‐tex®. Zymograms and Western blots were used to compare protease profiles of these cells with those of human gingival fibroblasts, keratinocytes and periodontal ligament (PDL) cells. All cell types except for keratinocytes produced a 72 kD protease. In contrast, keratinocytes were the only cells that produced 92 kD gelatinase. In some cell lines, notably those removed from patients after short periods of regeneration, collagenase was the major protease detected on gelatin substrate gels. Some of these cell lines also produced additional proteases including a low molecular weight protease (30 kD) not seen in gingival fibroblasts, PDL cells or

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00481.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Evidence is currently lacking that sulcus depths of fully erupted teeth remain unchanged in the presence of excellent oral hygiene and absence of overt gingival inflammation. In 44 healthy volunteers (age range 16–34 yr) exhibiting the above criteria, sulcus probing depths (PD) were measured with a flexible measuring strip at 6 mesio‐buccal (MB) and 6 bucco‐cervical (BC) sites on 6 occasions spanning a total period of 20 weeks. Analysis of the data obtained showed that PD had a total range of 0.5–4.5 mm, varying greatly between subjects, although each had a personally characteristic distribution of PD across different sites. Mean depths of MB sites and variations were greater than at BC sites. Fluctuations at BC sites may, however, be no more than measurement error whereas those at MB sites may be real, or may reflect the greater difficulty of access to MB sites than to

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00482.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Nerve fibers with substance P‐like immunoreactivity (SP‐IR) in the junctional epithelium (JE) of 32‐42‐d‐old rats were examined by both light and electron microscopy using the avidin‐biotin‐peroxidase complex method. The density of nerve fibers with SP‐IR was highest in the middle portion of the JE; however, a few fibers were localized in the coronal portion of the JE and close to the enamel surface. Also, rich innervation was found especially in the basal cell layer of the JE. Unmyelinated axons with SP‐IR in the connective tissue underlying the JE were enveloped by Schwann cells but lost their Schwann cell sheath almost completely in the JE. The axons often formed varicosities with SP‐IR as terminals in various areas of the JE. The terminals contained numerous large granular vesicles, small clear vesicles and a few mitochondria, and were surrounded by the cytoplasmic processes of the junctional epithelial cells. These terminals were sometimes located close to neutrophils in the JE; the minimum gap distance between the terminals and the processes of junctional epithelial cells or neutrophils was about 20 nm. A few terminals with SP‐IR came close to the enamel surface, and the minimal distance between the terminals and the enamel surface was about 5 μm. SP‐IR in the nerve terminals in the JE fixed with 0.1% or 0.25% glutaraldehyde was distributed diffusely in the axoplasm or was confined to the granular vesicles. These findings show that substance P is contained in the large granular vesicles in the nerve terminals, and suggest that these terminals may function as modulators of junctional epitheli

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00483.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Thirteen periodontally healthy subjects were monitored clinically for 6–12 months. Clinical measurements at 6‐weekly intervals included duplicate PD measurements, presence of plaque, redness, and bleeding on probing. Baseline measurements consisted of 2 visits I wk apart. Microbial samples were taken from 11 of the subjects who had completed at least 8 months of monitoring. Levels of serum antibodies to 12 periodontal species were determined from 10 subjects. Standard deviations of replicate PD measurements, computed for each subject, ranged from 0.2–0.3 mm over the monitoring period. Plaque and redness increased during monitoring, and showed a weak association with PD change. Baseline and follow‐up distributions of PD changes indicated that changes of>1.5 mm could reasonably be considered to represent active sites. Five subjects demonstrated at least 1 site deepening by 1.5 mm over the period monitored, and these were considered putative active subjects. Sites from 2 subjects showed PD increases in the 6 wk just before sampling, and these were considered to represent active sites. Species associated with putative active subjects includedActinomyces naeslundii, Veillonella parvula, Selenomonas noxiaandPrevotella nigrescens. Streptococcus sanguis, S.gordoniiandPeptostreptococcus microswere associated with inactive subjects.S. gordoniiandS. oraliswere associated with health, whereasP. nigrescenswas associated with gingivitis. Elevated serum antibodies were detected toA. actinomycetemcomitansin 4 subjects. The predominant microbiota of putative active subjects included some species previously associated with gingivitis, and some species previously associated with progressing period

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00484.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Growth factors are potent bioactive molecules responsible for the co‐ordination of many cell functions and interactions. Of these agents PDGF and IGF have shown particular promise as agents which may be used to stimulate periodontal regeneration. In order to further understand the mechanisms by which growth factors may work, a simple model ofin vitrowound healing has been utilized to assess the effects of PDGF on human periodontal ligament fibroblasts and its potential to stimulate wound healing. Human periodontal ligament fibroblasts were plated into 24‐well plates and upon reaching confluence were wounded by creating uniform discoid lesions stripped of cells. The influence of various concentrations of PDGF on cell proliferation, cell migration and extracellular matrix synthesis was monitored. The results of this study indicated that in the presence of 10 ng/ml PDGF and 0.2% fetal calf serum, both cell proliferation and cell migration were significantly stimulated. In the wounded cultures, PDGF appeared to cause a moderate stimulation of proteoglycan synthesis compared to unwounded cultures. In conclusion, the model system tested appears to be useful for studying fundamental cellular and biochemical events associated with wound healing. The effects of PDGF in this system confirm that it is capable of modulating fibroblasts in a manner compatible with the events associated with wound rep

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00485.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The present study was carried out to examine the antigen‐presenting cell (APC) functions of human gingival fibroblasts (HGF) elicited with IFNy. Stimulation of HGF with IFNy clearly induced HLA‐DR expression and enhanced expression of intercellular adhesion molecule‐1 (ICAM‐1) on HGF. Despite the phenotypical resemblance of IFNγ‐treated HGF to so‐called APC, HLA‐DR positive HGF were unable to induce proliferation of allo‐reactive peripheral blood T cells (PBT) isolated from different donors. The failure of IFNγ‐treated HGF to stimulate unprimed allo‐reactive PBT was not due to the lack of production of IL‐1 or the immunosuppressive effect of PGE2from HGF. On the other hand, the fact that detectable expression of CD80, ligand for CD28, was not found on IFNy‐treated HGF may at least in part explain the ineffective function of HGF as APC. Interestingly, IFNγ‐treated HGF induced proliferation of primed allo‐reactive CD4+T cells in a HLA‐DR dependent manner, suggesting that IFNγ‐treated HGF may have the ability to stimulate pre‐activated T cells. We then confirmed that high levels of IFNγ mRNA were detectable in inflamed gingival tissue. Although it cannot be concluded from this study that HGF are incapable of effectively presenting antigenic peptides to autologous T cells bearing appropriate T cell receptors, present results suggest that HGF may be affected by locally‐secreted IFNy and that the IFNγ‐stimulated HGF may play a role in regulating immune respons

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1996.tb00486.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY