bluuebunny/crossref_metadata_2025 huggingface dataset:
Bactericidal concentrations of chlorhexidine‐digluconate, amine fluoride gel and stannous fluoride gel for subgingival bacteria tested in serum at short contact times
Authors: Oosterwaal P. J. M. , Mikx F. H. M. , van den Brink M. E. , Renggli H. H.
Published: July 2006

In vitro inhibitory and bactericidal concentrations in serum of chlorhexidine‐digluconate, amine fluoride gel, stannous fluoride gel, stannous fluoride, metronidazole and amoxicillin were determined against Bacteroides gingivalis, Bacteroides intermedius, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans and Capnocytophaga sputigena. The minimal inhibitory concentration was assessed by the agar dilution technique. The killing curves and minimal bactericidal concentration of the antimicrobial agents in inactivated bovine serum were determined after 5, 10, 20 and 60 minutes contact time. The minimal inhibitory concentration varied amongst the tested bacteria. A concentration of 128 μg/ml chlorhexidine digluconate, 20 mg/ml amine fluoride gel, 1 mg/ml stannous fluoride, 128 μg/ml metronidazole and 4 μg/ml amoxicillin inhibited the growth of the tested species. The minimal bactericidal concentration in serum for B. gingivalis, B. intermedius, F. nucleatum, A. actinomycetemcomilans and C. sputigena after 10 min contact time was 5 mg/ml for chlorhexidine digluconate and 100 mg/ml for amine fluoride gel. A concentration of 200 mg/ml stannous fluoride gel in serum was bactericidal for the tested species after 10 min contact time, with exception of F. nucleatum.
Diabetes mellitus and periodontal disease in an Irish population
Authors: Hayden Peter , Buckley Louis A.
Published: July 2006

The prevalence of periodontitis was studied in a population of 157 insulin dependent diabetes mellitus patients aged 8–78 years attending the outpatients diabetic clinic of a large general hospital in Cork, Ireland. Every third diabetic patient attending the clinic was selected for examination. The dental parameters measured were plaque index (PI), gingivitis index (GI), periodontal pocket depth (PD) and periodontal attachment loss (PAL). Diabetic control was measured by estimating percentage haemoglobin glycolysation (% Hb Ale) known duration of diabetes (KDD) and insulin dependence. It was found that none of the diabetic measurements showed any consistent pattern in relation to any of the periodontal measurements. The findings are in agreement with other studies which suggest that no significant correlation between diabetic parameters and periodonlal disease can be demonstrated. When the diabetic patient suffered periodontitis it was due to factors (such as genetic predisposition) other than impaired glucose metabolism.
Hereditary gingival fibromatosis: Report on three families and dermatoglyphic analysis
Authors: Škrinjarić IIiJa , Bačić Miljenko
Published: July 2006

Some syndromes that include gingival fibromatosis are associated with abnormalities of the hands and feel. The purpose of this work was to establish whether gingival fibromatosis, as an isolated disease, can be connected with disturbances in the development of the digitopalmar structures. In three families with 40 members, fibromatosis manifested in 16 (7 males and 9 females). The disease was transmitted as an autosomal dominant trait. Dermatoglyphics were analyzed in the proband in each family and in their fathers who had fibromatosis. The analysis showed the presence of patterns in IV interdigital areas in all patients. The fathers of 2 probands had double loops in the IV interdigital area, which is very rare in the general population (frequency, 0.6%). The position of the axial triradius was moderately distal (t′) in 1, and markedly distal (t″) in another, and in 4 it was borderline (tb). Total finger ridge count was increased, which indicated the increased size of the volar embryonal pads. Distorted dermatoglyphic findings may be considered microform abnormalities of the fingers and hands. Since dermatoglyphics are highly genetically controlled and reflect the status of the embryonal pads, the results suggest disharmony in the development of the mesodermal structures of the hands.
Immunohistochemical localization of chondroitin sulfate and dermatan sulfate proteoglycan in human gingival connective tissue
Authors: Shibutani T. , Murahashi Y. , Iwayama Y.
Published: July 2006

This study investigated the immunohistochemical localization of chondroitin sulfate (chondroitin, 4‐sulfate and 6‐sulfate) and dermatan sulfate proteoglycan (PG) in human gingival connective tissue, using monoclonal antibodies. Dermatan sulfate was found to be widespread in connective tissue, with an especially strong response shown in collagen fiber bundles under the epithelial basement membrane. Chondroitin 4‐sulfale occurred widely in connective tissue but showed only a weak response. Chondroitin 6‐sulfate was located in peripheral blood vessels. Chondroitin was not detected in gingival connective tissue.
Regulation of human gingival fibroblast growth and synthetic activity by cyclosporine‐A in vitro
Authors: Bartold P. Mark
Published: July 2006

Gingival overgrowth is an adverse side‐effect seen in a proportion of patients taking cyclosporine‐A which indicates that cyclosporine‐A may modulate the activities of cells other than T lymphocytes. Therefore, the effect of cyclosporine on human gingival fibroblasts has been studied in vitro. Cyclosporine‐A was found to stimulate DNA synthesis and the proliferative activity of these cells with maximal stimulation noted at a concentration of 10–9g/ml. Although this stimulation was most noticeable in the presence of 10% fetal calf serum, proliferation still occurred in serum‐free medium. In the presence of lipopolysaccharide, at a concentration which normally inhibits ingival fibroblast proliferation, cyclosporine retained its capacity to stimulate proliferative activity. Fibroblasts isolated from overgrown gingival tissue responded to a greater extent than those isolated from a healthy site from the same individual. This stimulatory effect was not restricted to gingival fibroblasts, since human foreskin fibroblasts responded in a similar fashion. Cyclosporine‐A did not significantly alter protein or proteoglycan production by these cells. These responses are considered to reflect the in vivo response of gingival overgrowth in patients taking cyclosporine‐A. The reversal of lipopolysaccharide inhibition of gingival fibroblast proliferation by cyclosporine‐A may explain, in part, why gingival overgrowth is most prominent in areas of heavy dental plaque accumulation.
Detection of longitudinal change in periodontitis
Authors: Aeppli Dorothee M. , Pihlstrom Bruce L
Published: July 2006

In any longitudinal study of periodontitis, it is important to determine when change in probing depth or clinical attachment level occurs as soon as possible. In this study, simulation was used to compare three statistical methods for detecting change in linear periodontal measurement under a variety of conditions including type of change, number of follow‐up visits, magnitude of linear measurement and examiner variance. The statistical methods included: 1) testing the slope of a regression line, 2) a comparison of running medians and 3) the cumulative sum (cusum) method. Three types of change and random examiner error were imposed on baseline linear measurements. The types of change included a gradual change, a burst, and rapid loss followed by regeneration. The results indicated that all three methods yielded similar results when the change was gradual. However, the regression line was less sensitive to bursts of change than the other methods. Overestimation of examiner error for the running median and cusum methods increased specificity and decreased sensitivity. Underestimation of examiner variance decreased specificity and increased sensitivity of the cusum and running median methods, while the regression was unaffected by estimates of examiner variance. If preventive or therapeutic action does not need to be taken immediately, either the running median or the cusum would be a good choice for detecting change. If immediate intervention is needed, the cusum appears to be the method of choice for detecting change at specific sites in longitudinal periodontal studies.
Patterns of healing on replanted baboon incisors coated with an allogeneic fibrin‐fibronecftin protein concentrate
Authors: Ripamonti Ugo , Petit Jean‐Claude
Published: July 2006

This study investigated the use of an allogeneic fibrin‐fibronectin protein concentrate (AFFP) in preventing ankylosis and root resorption on replanted teeth during healing. In 2 adult male baboons (Papio ursinus) after extraction of the mandibular incisors, the coronal two‐thirds of the exposed roots were planed to remove the remnant of the periodontal ligament and the cementum. The exposed dentinal surfaces were demineralized with citric acid at pH 1 for 3 min and notched at the junction between the planed and non‐planed surfaces. Before replantation, the experimental roots and alveoli were coated with the AFFP prepared from pooled fresh‐frozen baboon plasma. The animals were killed 55 days after operation and histometrical analysis was performed on serial sections cut in the buccolingual direction parallel to the long axis of the recovered specimens. An analysis of variance demonstrated significant differences between the two treatments with regard to the magnitude of ankylosis (greater for citric acid‐demineralized plus AFFP‐treated surfaces). There were variations in the magnitude of the different patterns of healing both between and within the experimental and control surfaces. Within the limits of the study, in this primate replantation model, the biochemical treatment of surgically exposed and demineralized root surfaces with AFFP did not enhance connective tissue attachment regeneration nor prevent dentoalveolar ankylosis and root resorption.
Effects of lathyrogens on the mechanical strength of the periodontal ligament in the rat mandibular first molar
Authors: Ohshima S. , Nakamura G. , Chiba M.
Published: July 2006

Effects of lathyrogens such as aminoacetonitrile (AAN), β‐aminopropionitrile (BAPN) and cysteamine – known inhibitors of cross‐linking of collagen – on the mechanical strength of the periodontal ligament of the rat mandibular first molar were examined by measuring the ultimate load required to extract the tooth from its socket in the dissected jaw. Single injections of AAN (40 ∼ 100 mg/100 g body weight) or of BAPN (100 mg/100 g body weight) caused significant decreases of the mechanical strength 24 h after administration of the drugs but that of cysteamine (30 mg/100 g body weight) did not. Significant correlations between the dose of AAN or of BAPN and the mechanical strength were found following daily administrations of the drugs for 5 days. The relative potency of AAN to BAPN was estimated to be 4.5 by a slope ratio assay. The rapid appearance and disappearance of the effect of lathyrogens on the mechanical strength of the periodontal ligament of the rat mandibular first molar provide further evidence that the turnover of the collagen in the tissue is fast. The half‐time of collagen synthesis was estimated to be approximately 3 d.
Detection of cathepsin B‐ and L‐, elstase‐, tryptase‐, trypsin‐, and dipeptidyl peptidase IV‐like activities in crevicular fluid from gingivitis and periodontitis patients with peptidyl derivatives of 7‐amino‐4‐trifluoromethyl coumarin
Authors: Cox S.W. , Eley B. M.
Published: July 2006

Crevicular fluid samples were collected from 20 gingivitis and periodontitis patients using filter paper strips; these were then eluted into buffer. Portions of each sample were combined and the activities of this pooled eluate against different peptidyl derivatives of 7‐amino‐4‐trifluoromethyl coumarin (AFC) were examined with respect to their pH profiles and effector responses. Cathepsin B‐ and L‐like activity was detected with Bz‐Val‐Lys‐Lys‐Arg‐AFC; elastase‐like activity with MeOSuc‐Ala‐Ala‐Pro‐Val‐AFC; tryptase‐like activity with Z‐Ala‐Ala‐Lys‐AFC; trypsin‐like activity with Z‐Gly‐Gly‐Arg‐AFC; and dipeptidyl peptidase (DPP) IV‐like activity with Ala‐Pro‐AFC. The selectivity and sensitivity of these assays were improved by choice of appropriate conditions. The cathepsin B‐ and L‐, elastase‐, tryptase‐, and trypsin‐like activities all had properties consistent with those from host sources, whilst partial inactivation of the DPP IV‐like activity by heat treatment (60°C for 30 min) suggested that it may have represented a mixture of human and Bacteroides gingivalis enzymes. Individual patient eluates showed wide variations in enzyme concentrations, but generally elastase‐like activity was by far the highest. The sensitivity of the assays with AFC‐linked substrates was such that it should prove possible to measure all five different types of activity in crevicular fluid samples from local periodontal disease sites.
Increased interleukin‐1 beta (IL‐1β) concentration in gingival tissue from periodontitis patients
Authors: Hönig J. , Rordorf‐Adam C. , Siegmund C. , Wiedemann W. , Erard F.
Published: July 2006

Human gingival tissues from periodontitis patients were found to contain from 126 fg/mg to 2161 fg/mg interleukin‐1 beta as determined by a sensitive enzyme linked immunoassay. No IL‐ 1 β could be found in normal gingival tissue. This finding may have important consequences relevant to connective tissue destruction and episodes of alveolar bone resorption characteristic of chronic periodontitis.
Appearance of osteoclasts by injections of lipopolysaccharides in rat periodontal tissue
Authors: Umezu Akira , Kaneko Nobuo , Toyama Yosuke , Watanabe Yoshihisa , Itoh Haruo
Published: July 2006

The effect of lipopolysaccharides (LPS) on periodontal tissue was studied in 11‐week‐old Wistar rats. Four injections of 500 μg LPS induced marked osteoclastic alveolar bone resorption, whereas no alveolar bone resorption occurred after four injections of physiological saline. The osteoclast count increased progressively during the four injections of 500 μg LPS. After eight injections, however, the osteoclast count fell from the maximum level after four injections, although osteoclasts continued to increase in size and demonstrate an increased number of nuclei. Comparison of the osteoclast number between a series of four injections of 5, 50 or 500 μg LPS each revealed a dose‐dependent increase. This strongly suggests LPS induction of osteoclastic bone resorption in vivo. Combined use of indomethacin, a prostaglandin synthesis inhibitor, with LPS injections inhibited both the LPS‐induced alveolar bone resorption and osteoclast increase, suggesting a possible participation of prostaglandins in osteoclast‐mediated bone resorption.
Increased periodontal bone loss in temporarily B lymphocyte‐deficient rats
Authors: Klausen Bjarne , Hougen Hans Petter , Fiehn Nils‐Erik
Published: July 2006

In order to study the role of T lymphocytes and B lymphocytes in the development of marginal periodontitis, experiments were performed on specific‐pathogen‐free (SPF) rats with various immunologic profiles. The study comprised nude (congenitally T lymphocyte‐deficient), thymus‐grafted nude (T‐lymphocyte reconstituted), anti‐μ treated (temporarily B lymphocyte‐deficient), and normal rats. When they were 5 to 9 weeks old, some of the rats were inoculated with Actinomyces viscosus, Bacteroides gingivalis and a strain of oral spirochetes; 90 days later they were killed. A. viscosus and B. gingivalis colonized readily, but the spirochete strain could not be established permanently in the oral cavity of the rats. 95% of the inoculated rats raised serum IgG or IgM antibody against one or more of the microorganisms; nude rats tended to raise less antibody than the three other experimental groups. Inoculated rats had significantly less periodontal bone support than controls. Anti‐μ treated inoculated rats had significantly less periodontal bone support than nude and normal rats, whereas no difference was found between normal, nude, and thymus‐grafted rats. It is concluded that permanent T‐lymphocyte deficiency did not interfere with the development of periodontal disease in this model, whereas a temporary and moderate reduction in B‐lymphocyte numbers seemed to predispose for aggravation of periodontal bone loss.
Correction of density changes caused by methodological errors in CADIA
Authors: Steffensen B. , Pasquali L A. , Yuan C. , Wood R. C. , Schoolfield J. D. , Kornman K. S.
Published: July 2006

Quantitative evaluation of radiographic changes by computer‐assisted densitometric image analysis (CADIA) requires exact knowledge about method errors. In the present study, density change errors were determined from pairs of films with “no change”. From this distribution of error values, a series of threshold values for correction of changes due to method errors was selected. The threshold values were then applied to results from analysis of densitometric changes in sites with “known loss” or “no change” of the alveolar bone among films from cynomolgus monkeys. The density errors formed non‐normal distributions with no difference in magnitudes between the absolute values expressing density decreases and density increases in the same areas. Calculation of sensitivity, specificity, type 1 and type 2 errors showed that these variables were clearly influenced by selection of different threshold values for correction of the density change errors. It is therefore recommended that threshold values be determined for each analytical system initially as well as following any equipment or computer program modification. Before selecting the threshold value for a specific radiographic analysis, the desired level of sensitivity and specificity should be evaluated.
Interleukin‐2 stimulates osteoclastic activity; Increased acid production and radioactive calcium release
Authors: Ries William L. , Seeds Michael C. , Key L. Lyndon
Published: July 2006

Recombinant human interleukin‐2 (IL‐2) was studied to determine effects on acid production by individual osteoclasts in situ on mouse calvarial bones. This analysis was performed using a microspectrofluorimetric technique to quantify acid production in individual cells. Radioactive calcium release was determined using calvarial bones in a standard tissue culture system. This allowed us to correlate changes in acid production with a measure of bone resorption. IL‐2 stimulated acid production and bone resorbing activity. Both effects were inhibited by calcitonin. No stimulation of bone resorption occurred when IL‐2‐containing test media was incubated with a specific anti‐IL‐2 antibody and ultrafiltered. Our data demonstrated a correlation between acid production and bone resorbing activity in mouse calvaria exposed to parathyroid hormone (PTH). The data obtained from cultured mouse calvaria exposed to IL‐2 demonstrated similar stimulatory effects to those seen during PTH exposure. These data suggest that calvaria exposed to IL‐2 in vitro have increased osteoclastic acid production corresponding with increased bone resorption.
Collagen membranes prevent apical migration of epithelium and support new connective tissue attachment during periodontal wound healing in dogs
Authors: Pitaru S. , Tal H. , Soldinger M. , Noff M.
Published: July 2006

The capacity of collagen membranes to prevent the apical migration of epithelium and to support new connective tissue attachment was assessed in experimental perodontal defects in dogs. Experimental periodontal defects were produced in 8 mongrel dogs by removing the alveolar bone and the periodontal ligament over the most coronal 5 mm of the labial aspect of the maxillary canines. Experimental defects associated with the right canine and its surrounding bone were covered by collagen membranes prepared by air drying gels of rat type I fibrillar collagen. Flaps were repositioned and sutured. The contralateral control defects were sham‐operated without using collagen membranes. Animals were killed, 10 and 30 days after surgery, 4 at each time point. The experimental and control sites were processed for histologic and histomorphometric evaluation. At 10 d, the average distance between the apical margin of the epithelium and the apical level of the defect (EA) sites was 3.20±0.55 mm for the experimental sites and 0.73±0.18 mm for the controls. The experimental root surfaces apical to the epithelium and the collagen membranes were covered by connective tissue cells. At 30 d, the EA for experimental and control sites were 2.55±0.36 mm and 0.47±0.30 mm, respectively. In the experimental sites healing by long junctional epithelium was observed in the coronal 40% of apicoocclusal dimension of the defect and new connective tissue attachment with inserting fibers in the apical 55% of the defect length. No new bone formation was observed. In the control sites, pocket formation was found in the most coronal one‐third of the defect. Healing by long junctional epithelium was found in the most apical two‐thirds of the defect. Collagen membrane remnants were not identified at 30 d. These results indicate that collagen membranes have the capacity to partially prevent epithelial apical migration and to support new connective tissue attachment formation in experimental periodontal defects in the dog.
Immunohistochemical study of neurochemical markers in gingiva obtained from periodontitis‐affected sites
Authors: Luthman Johan , Friskopp Johan , Dahliöf Göran , Ahlström Ulf , Sjöström Lars , Johansson Olle
Published: July 2006

Immunohistochemical methods have been used to study the occurrence of neuronal markers in human gingiva from periodontitis‐affected sites. In periodontitis‐affected buccal gingiva densely distributed neurofilament (NF)‐immunoreactive (IR) fiber bundles were observed in the deeper parts of the propria, while NF‐IR single finbers occurred in the superficial propria and occasionally in the buccal epithelium. Periodontitis‐affected gingiva obtained from interproximal sites showed only sparsely distributed NF‐IR fibers. Single nerve fibers immunoreactive to the peptides substance P and calcitonin gene‐related peptide occurred close to or within the epithelium in both buccal and interproximal gingiva. Around blood vessels neuropeptide Y‐, peptide histidine‐isoleucine amide‐ and vasoactive intestinal polypeptide‐IR fibers were occasionally observed, while clusters of γ‐melanocyte‐stimulating hormone‐IR cells were found in the propria, in addition to γ‐melanocyte‐stimulating hormone IR nerve fibers. Somatostatin‐IR dendritic cells were seen in epithelium and propria of buccal and interproximal gingiva, although a high variability in the number of SOM‐IR cells was observed. All neuronal markers studied showed a similar distribution in material obtained from young patients with clinically healthy gingivae, although the number of NF‐IR fibers in the propria in these subjects was lower. The results demonstrate that in gingiva obtained from periodontitis‐affected sites several different biologically active peptides occur in both nerve fibers and cells. At least some of these substances could possible play a role in the inflammatory process. However, since clinically normal gingiva was shown to contain nerve fibers and cells expressing immunoreactivity to the substances studied, no unique periodontitis‐induced expression of the neuronal markers studied was found. Thus, any alteration of these substances during the periodontitis process remains to be elucidated.
Depressed helper‐to‐suppressor T‐cell ratios in early‐onset forms of periodontal disease
Authors: Kinane D. F. , Johnston F. A. , Evans C. W.
Published: July 2006

Helper (CD4+)‐to‐suppressor (CD8+) T‐cell ratios were determined by flow cytometry for 12 patients with early‐onset forms of periodontal disease and their appropriate controls. When considered as a group, patients with early‐onset periodontal disease showed a markedly depressed CD4+/CD8+ ratio relative to controls (means 0·92 and 1·50 respectively). This difference was significant at the 0·0015% level as determined by the Mann‐Whitney test. Separate analysis of patients with either the juvenile or rapidly progressive types of early‐onset periodontal disease showed both to have reduced CD4+/CD8+ ratios (means 0·91 and 0·92) relative to their controls (means 1·57 and 1·45) which were both statistically significant (p<0·05).
Inhibitory effects of rabbit antisera on mitogenic activity of Actinobacillus actinomycetemcomitans lipopolysaccharide
Authors: Nishihara T. , Maki E. , Ishihara Y. , Kato H. , Noguchi T. , Koga T.
Published: July 2006

Lipopolysaccharides (LPSs) were isolated from Actinobacillus actinomycetemcomitans strains ATCC 29523 (serotype a), Y4 (b), and NCTC 9710 (c) by the hot phenol‐water procedure. Y4 lipid A was obtained by the hydrolysis of Y4 LPS in 1 % acetic acid. All the LPS preparations and Y4 lipid A were mitogenic for C3H/HeN mouse spleen cells, but not for C3H/HeJ mouse spleen cells. Immuno‐globulin preparations partially purified by ammonium sulfate precipitation at 33% saturation from rabbit antisera against Y4 whole cells inhibited the mitogenic response of C3H/HeN mouse spleen cells to LPSs from all the strains of A. actinomycetemcomitans and Y4 lipid A. Anti‐Y4 LPS immunoglobulin preparation inhibited the mitogenic acuvity of Y4 LPS and Y4 lipid A. Furthermore, anti‐Y4 whole cell Fab fragments inhibited the mitogenic activity of both Y4 LPS and Y4 lipid A. These results suggest that antibodies against A. actinomycetemcomitans LPS may modify immune responses of lymphocytes to this organism at periodontal sites.
Heterogeneity of virulence among strains of Bacteroides gingivalis
Authors: Neiders M. E. , Chen P. B. , Suido H. , Reynolds H. S. , Zambon J. J. , Shlossman M. , Genco R. J.
Published: July 2006

The ability of fresh isolates of B. gingivalis to establish abscesses in the mouse model was studied by comparing them with established laboratory strains of B. gingivalis. Eight fresh isolates obtained from plaque associated with periodontal disease and grown under similar conditions as established strains were injected subcutaneously on the back of the mouse. All of these strains produced secondary lesions on the abdomen. Septicemia was associated with seven of the strains. Two commonly used laboratory strains, W50 and W83, also produced secondary lesions and septicemia. Five other laboratory strains produced only localized abscesses. On histologic examination, the strains that produced disseminated disease showed invasion of connective disease by individual bacteria that were not in clumps. The strains that produced localized abscesses were characterized by growing in colonies or clumps in the abscess cavity. Four synthetic enzyme substrates were examined to determine whether the differences between invasive and non‐invasive strains were due to differences in proteolytic enzyme production. No differences in enzyme production could be demonstrated with the selected substrates.
Gingival fibroblasts degrade type I collagen films when stimulated with tumor necrosis factor and interleukin 1: Evidence that breakdown is mediated by metal loproteinases
Authors: Meikle Murray C. , Atkinson Susan J. , Ward Robin V. , Murphy Gillian , Reynolds John J.
Published: July 2006

We previously suggested that periodontal pathogens might mediate connective tissue degradation in periodontal diseases through the ability of antigens from their cell walls to stimulate cytokine production by circulating mononuclear cells. Such cytokines would then induce metalloproteinase (MP) synthesis by resident gingival cells and thus initiate matrix degradation. In the present investigation human gingival fibroblasts (HGFs) were grown on [14C]‐labelled type I collagen films and stimulated with either tumor necrosis factor (TNF) or interleukin‐1 (1L‐1) for 48 h. Collagenolysis occurred in a dose‐dependent manner; the optimal dose for human rTNFα was l00ng/ml and for rIL‐lα and rIL‐lβ, 1 ng/ml. Collagen degradation was accompanied by increased synthesis and release of the MPs collagenase, gelatinase and stromelysin, and there was a reduction in free TIMP (tissue inhibitor of metalloproteinases): collagenase and stromelysin were detected in both active and latent forms. Cytokine‐stimulated collagenolysis was abolished by the addition of exogenous human rTIMP (5 units/ml). We also measured collagenase and TIMP by ELISAs which recognize all forms of collagenase (latent, active or complexed) and TIMP (free or eomplexed). These showed that while collagenase activity (0·6–1·2 μg/ml) correlated with lysis, total TIMP levels remained unchanged at approximately 0·2 μg/ml. These results demonstrate important roles for MPs and TIMP in regulating type I collagen degradation by HGFs, and support the hypothesis that connective tissue destruction during inflammatory diseases may be initiated, at least in part, by TNF and IL‐1.
Cathepsins B, H and L activities in gingival crevicular fluid from chronic adult periodontitis patients and experimental gingivitis subjects
Authors: Kunimatsu Kazushi , Yamamoto Kenji , Ichimaru Eiji , Kato Yuzo , Kato Ihachi
Published: July 2006

To clarify roles of lysosomal cysteine proteinases cathepsins B, H and L in pathological destructive process of periodontal tissues, levels of their enzymatic activities were determined in gingival crevicular fluid (GCF) from chronic adult periodontitis patients and from experimental gingivitis subjects. In periodontitis patients, higher levels of cathepsins B, H and L activities were found at sites with more serious signs of the disease activity. The total activity of each enzyme (per unit time) was positively correlated with the GCF volume. However, it had little or no correlation with the probing depth (PD). In contrast, the specific activity of each enzyme in GCF (activity units per mg protein), which reflects the selectivity of enzyme exudation, was negatively correlated with the GCF volume. These results suggest that the cysteine proteinases are selectively released into gingival crevices at a relatively mild stage of periodontitis. In experimental gingivitis subjects, no significant activity of each enzyme was detected in GCF, even when the quantity of GCF was comparable to that from periodontitis patients. These data suggest that no significant amounts of these enzymes are released at experimental gingivitis sites or that a homeostatic mechanism, including regulation by protease inhibitors, may control activities of these enzymes in GCF with acute inflammation.
Effect of cell donor age on the synthetic properties of fibroblasts obtained from phenytoin‐induced gingival hyperplasia
Authors: Johnson Bradley D. , Narayanan A. Sampath , Pieters Helen P. , Page Roy C.
Published: July 2006

Diploid fibroblasts obtained from explants of human gingiva and maintained in vitro undergo a several‐fold decrease in protein and collagen synthesis as a function of increasing donor age. Using drug‐induced gingival hyperplasia as a model, we performed experiments to learn whether fibroblasts derived from hyperplastic tissue behave in a similar manner. Fibroblast strains were established from explants of hyperplastic gingiva obtained from 10 patients chronically ingesting phenytoin and ranging in age from 9 to 45 years. Protein production and degradation were compared to previously reported data similarly obtained from periodontally normal donors ranging in age from 12 to 68 yr. The total quantity of protein and collagen produced by the phenytoin cells was significantly greater than previously reported for cells from normal gingiva. No donor agerelated decrease in protein and collagen production nor in the proportion of cell synthetic activity committed to collagen production was observed for cultures of phenytoin cells. The gross pattern of proteins produced, as assessed by 2‐dimensional gel electrophoresis, was unrelated to donor age in both normal and phenytoin cells, but three polypeptides ranging in size from about 20 kD to 40 kD that were not found in the cultures of normal cells were produced by five of seven phenytoin cells strains. The observations demonstrate that the phenytoin cells do not undergo the donor age‐dependent decrease in synthesis observed for normal cells. This abnormality may account in part for the phenytoin‐induced hyperplasia. The phenytoin cells appear to be a unique phenotype.
Relationship between gingival crevicular fluid levels of aspartate aminotransferase and active tissue destruction in treated chronic periodontitis patients
Authors: Persson G. Rutger , De Rouen Timothy A. , Page Roy C.
Published: July 2006

Data from several sources demonstrate that disease‐active and disease‐inactive periodontal pockets exist, and that disease progression occurs in bursts of activity. Currently used diagnostic procedures do not distinguish between disease‐active and disease‐inactive sites at any given point in time. We report the results of studies aimed at determining whether levels of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) are associated with disease activity as assessed by the level of gingival inflammation and probing attachment loss. 25 previously treated periodontitis patients participating in a quarterly recall maintenance program, who had experienced recurrent periodontal deterioration, served as experimental subjects. Patients were evaluated at 3‐month intervals for 2 years. Values for plaque index, gingival index, and probing attachment level were recorded, and 30‐second samples of gingival fluid harvested from the mesiobuccal aspect of the 4 first molars and the distal of the 4 lateral incisors. GCF volume was measured using a Periotron 6000, and AST activity was measured by a standard method. Sites were ranked in a hierarchy based on the degree of certainty of attachment loss as well as the severity of gingival inflammation, and the relationship of the values to AST levels was determined. Three models were used to analyze the resulting data, and all led to the same conclusion. Maximum enzyme level was significantly elevated at sites with confirmed disease activity as assessed by attachment loss, with maximum AST levels 725 units higher at these sites, on average, than at other sites (p < 0.0001). Maximum AST values were also associated with severe gingival inflammation (p < 0.005) where values were about 600 units higher than at sites with mild or with no gingival inflammation. Our data support the idea that an objective diagnostic test, based on levels of AST in GCF, that distinguishes between disease‐active and disease‐inactive sites may be possible.
Flurbiprofen in human crevicular fluid analyzed by highperformance liquid chromatography
Authors: Heasman P. A. , Ward A. , Barrett A. W. , Seymour R. A. , Edwards G.
Published: July 2006

The aim of this study was to determine whether the non‐steroidal anti‐inflammatory drug, flurbiprofen, which has been shown to be an inhibitor of alveolar bone loss in human periodontal disease, is present in human crevicular fluid (CF) following oral dosing. A method is described whereby routine highperformance liquid chromatography is used to detect the drug in only 20 μ1 of CF. 5 volunteers abstained from toothbrushing for 21 days to induce experimental gingivitis and increase the resting flow of CF. 100 mg of flurbiprofen was taken by each volunteer on d 21‐28. On d 21 and 28, serum and CF samples were taken prior to dosing and afterwards at 1, 2, 4 and 6 hours. On d 21 the mean peak concentration of the drug in serum was about 11 μg/ml and was found between 1–2 h after dosing. The respective values for CF (d 21) were 0.32 μg/ ml and 4 h. On d 28 flurbiprofen was detected in both fluids prior to dosing. The mean peak concentrations after dosing had increased to 13.13 μg/ml (serum) and 0.46 μg/ml (CF) although the levels of the drug in CF remained relatively constant throughout the observation period on d 28. The results indicate that flurbiprofen may be detected in human CF after oral administration and that the levels are in excess of the plasma level, which in beagles has been shown to inhibit alveolar bone loss in periodontal disease.
Isolation of a fibroblast attachment protein from cementum
Authors: McAllister B. , Narayanan A. S. , Miki Y. , Page R. C.
Published: July 2006

Cementum forms the interface through which soft connective tissue of the periodontium is attached to the root surface. The interactions between cementum and connective tissue are not completely understood and whether cementum influences periodontal connective tissue formation and regeneration is not clear. We have examined the effect of cementum components on the attachment of gingival fibroblasts. Cementum was harvested from healthy human and bovine teeth and extracted sequentially in 0.5 M CH3COOH, 4 M guanidine and bacterial collagenase. Fibroblast attachment was measured using 51Cr‐labelled human gingival fibroblasts on tissue culture plates previously incubated with cementum components. Results showed that all three extracts mediated fibroblast attachment and attachment was dependent on concentration and incubation time. The attachment activity was not destroyed by digestion with bacterial collagenase or by antibodies to fibronectin and laminin. However, it was inhibited by a peptide containing the amino acid sequence RGD. By gel filtration or HPLC using a DEAE‐cellulose column several proteins with attachment activity were fractionated. SDS‐polyacrylamide gel electrophoresis revealed that HPLC fraction eluted by 0.2–0.3 M NaCl contained a protein with molecular weight 55 kDa as a major component. This protein was isolated and shown to promote fibroblast attachment, and optimal attachment occurred at a concentration of 2 μg/ml. We conclude that cementum contains substances capable of mediating fibroblast attachment and that these substances play an important role in periodontal connective tissue formation and regeneration by facilitating fibroblast attachment to root surfaces.
Effect of phenytoin medication on the metabolism of epidermal growth factor receptor in cultured gingival fibroblasts
Authors: Modéer T. , Mendez C. , Dahllöf G. , Andurén I. , Andersson G.
Published: July 2006

Human gingival fibroblasts derived from 2 patients before and 9 months after the start of phenytoin (PHT) therapy were studied with respect to the effect of epidermal growth factor (EGF) on the incorporation of 3H‐thymidine into DNA, binding of EGF to its cell‐surface receptor, internalization of EGF‐receptor‐ligand complexes and, finally, with respect to EGF receptor mRNA levels. In fibroblasts derived from the patient who developed gingival overgrowth during the PHT medication (responder) as well as in the fibroblasts derived from the patient where gingival overgrowth did not develop (non‐responder), the affinity of the EGF receptor for EGF was not significantly changed. In the non‐responder patient the internalization of EGF receptor ligand was decreased, whereas it was increased in the fibroblasts derived from the responder patient after PHT therapy. The steady‐state level of EGF‐r mRNA increased significantly (p < 0.001) in the cultured fibroblasts derived from the non‐responder but decreased (p < 0.05) in the responder patient following PHT therapy. Ligand affinity cross‐linking studies revealed one major component of EGF receptor with a molecular weight of 170 KDa in fibroblasts from the non‐responder as well as from the responder. The study indicates that PHT medication results in a down‐regulation of EGF receptor metabolism in fibroblasts derived from a responder patient, whereas in the non‐responder patient EGF receptor metabolism is up‐regulated.
Estimation of sensitivity and specificity of site‐specific diagnostic tests
Authors: Hujoel P. P. , Moulton L. H. , Loesche W. J.
Published: July 2006

Clinical trials designed to estimate the sensitivity and specificity of periodontal diagnostic tests often use multiple sites per patient as experimental units of analyses. Since site‐specific test results within a patient are dependent observations, a correlated binomial model should be employed to estimate the sensitivity and specificity of these diagnostic tests. Ignoring the within‐patient correlation can result in an over‐ or underestimation of the true standard errors.
Sulfadiazines prevent plaque formation and gingivitis in beagles
Authors: Howell T. H. , Reddy M. S. , Weber H. P. , Li K. L. , Alfano M. C. , Vogel R. , Tanner A. C. R. , Williams R. C.
Published: July 2006

The effect of zinc sulfadiazine (ZnSD) and silver sulfadiazine (AgSD) on developing plaque formation and gingivitis was studied in 12 beagle dogs over a 14‐week period. Plaque and gingival indices were used to measure plaque formation and gingivitis. During a 2‐wk baseline period each dog was brought to optimal gingival health with prophylaxis and tooth brushing. Thereafter, 4 dogs were treated twice daily with topical application of 3.0% zinc sulfadiazine; 4 dogs were treated with 2.0% silver sulfadiazine while 4 dogs treated with placebo gel served as controls over a 12‐wk treatment period. At wk 2 of treatment, all three groups of dogs showed an increase in plaque build‐up on their teeth from baseline. By wk 6, plaque accumulation on the teeth was significantly less in dogs treated with either ZnSD or AgSD compared to control dogs. At wk 2 of treatment, gingival inflammation was increased from baseline in all three groups. Thereafter, over the course of the 12‐wk treatment period, gingival inflammation in the ZnSD and the AgSD treated dogs was significantly less than the placebo treated dogs. The data indicate that both ZnSD and AgSD inhibit developing plaque formation in beagles. This significant inhibition of plaque formation was accompanied by a significant reduction in gingival inflammation.
The release of interleukin‐1β, tumor necrosis factor‐α and i nterferon‐γ by cultured peripheral blood mononuclear cells from patient swith periodontitis
Authors: McFarlane Christine G. , Reynolds John J. , Meikle Murray C.
Published: July 2006

The extracellular release of IL‐1β by cultured peripheral blood monocytes from 26 periodontitis patients and 26 control subjects was measured by radioimmunoassay. Unstimulated monocytes from periodontitis patients released significantly more IL‐1β than controls during 24 h of culture; there was a wide variation in the amount of IL‐1β released (0.45–13.00 ng/ml per 106 cells) which did not correlate with either the degree of bone loss or pocket formation observed clinically. When stimulated with lipopolysaccharide (LPS; Actinobacillus actinomycetemcomitans; 5 μg/ml) monocytes from periodontitis patients produced significantly more IL‐1β than those from control subjects. Monocyte culture supernatants from another 10 periodontitis patients and 10 control subjects were also assayed for both IL‐1β and TNF‐α by enzyme‐linked immunosorbent assays. Spontaneous and LPS‐stimulated (Bacteroides gingivalis; 5 μ/ ml) IL‐1β release were again significantly higher for periodontitis patients. TNF‐α was detected in the periodontitis cultures (0–765 pg/ml per 106 cells), but the mean value was not significantly different from controls. LPS‐stimulated TNF‐α release, however, was significantly higher than for control subjects, and there was a strong correlation between spontaneous IL‐1β and TNF‐α release by monocytes from the periodontitis group. Measurement of interferon‐γ (IFN‐γ) in lymphocyte cultures from these patients by immunoradiometric assay showed that IFN‐γ levels in periodontitis cultures were consistently low, but not significantly so when compared to controls; both groups responded equally to concanavalin‐A (5 μg/ml). Although the precise roles of IL‐1β and TNF‐α in periodontitis remain unclear, these data provide evidence that both cytokines may participate in the pathogenesis of the disease.
Migration of epithelial cells on materials used in guided tissue regeneration
Authors: Salonen Jukka I. , Persson G. Rutger
Published: July 2006

Materials used in guided tissue regeneration were examined in an in vitro model for regenerating human junctional epithelium. The extent of epithelial migration from gingival explants (epibolus) between the explant and an experimental substratum was significantly greater with a Millipore® filter (HA) than with a teflon membrane (Biopore®; BO) and a teflon periodontal material (Gore‐Tex®; GT). Epithelial cells attached to HA, formed a morphologically and functionally distinct layer of proliferating cells along the substratum. In contrast, epithelial cells did not attach to either teflon material. The cells adjacent to the teflon substrata were nonproliferative and exhibited signs of degeneration or cell differentiation. Furthermore, epithelial cell migration along BO was significantly greater than along GT. Our results suggest that the low protein‐binding capacity of the teflon material and the rough‐textured surface of GT inhibit epithelial cell migration. The results may provide a rationale for understanding the differences in epithelial behavior after conventional therapy for periodontitis and during guided tissue regeneration.
Assessment of the efficacy of a nonsteroidal anti‐inflammatory drug, Naprosyn®, in the treatment of gingivitis
Authors: Johnson Robert H. , Armitage Gary C. , Francisco Carol , Page Roy C.
Published: July 2006

A double‐blind, placebo‐controlled trial was conducted to determine the effects of the nonsteroidal anti‐inflammatory drug Naprosyn® (naproxen) on gingival inflammation. The enrollment of 114 patients provided 102 patients valid for efficacy evaluation, each having a mean gingival index (GI) score of 1.5 or greater at test‐teeth sites. Patients were given oral Naprosyn 500 mg b.i.d. or placebo for 30 days. At 28 d, full‐mouth prophylaxis was performed. Gingival index, modified sulcular bleeding index (SBI), and plaque index (PI) scores were taken at baseline, at 28 d, and at 30 d. When the 28‐d index measurements were compared to baseline, the drug had no significant effect on plaque index scores or gingival inflammation. Statistically, Naprosyn enhanced the resolution of gingival inflammation following removal of microbial plaque. Thus, although this drug does not suppress the inflammation‐inducing properties of plaque, Naprosyn may enhance recovery following plaque removal.
Effect of sampling time and repetition on gingival crevicular fluid and aspartate aminotransferase activity
Authors: Persson G. Rutger , Page Roy C.
Published: July 2006

Tests based on the composition of gingival crevicular fluid (GCF) for detection of active periodontitis require a better understanding of sampling variables than currently exists. We have studied the effects of sample time and repetition on the presence and activity of aspartate aminotransferase (AST). Two 30‐second samples of GCF were harvested within 10‐minute intervals from 192 teeth with periodontitis. GCF sample size and AST activity were measured. GCF volume and AST activity of first samples were each approximately 10% greater than for second samples. The differences were significant. AST activity correlated positively with gingival index scores and probing pocket depth. Samples were also harvested from groups of 4 teeth during 5‐, 10‐, 20‐ and 30‐s periods with 1‐min intervals and varying sample order. For these samples, first samples contained the greatest amount of enzyme activity, regardless of sample time. When only first samples were considered, the 5‐ and 10‐s samples showed more total activity than the 20‐ and 30‐s samples, and differences were statistically significant. Flow rate for the 5‐s sample was always higher than for all other samples, regardless of its position in the sampling sequence. Our observations are consistent with the existence of a reservoir of AST activity that is, in major part, depleted during the first 5 to 10 s of sampling, and that requires a time period of more than 10 min to reequilibrate. Five‐ to 10‐s samples may distinguish active disease better than 20‐ or 30‐s samples, since most of the activity is taken onto the strip in the first few seconds, and the activity is subsequently partly inactivated or diluted by the uptake of fluid less rich in enzyme activity.