bluuebunny/crossref_metadata_2025 huggingface dataset:
Dark‐pigmented Bacteroides species in subgingival plaque of adult patients on a rigorous recall program
Authors: Wolff Larry F. , Liljemark William F. , Pihlstrom Bruce L. , Schaffer Erwin M. , Aeppli Dorothee M. , Bandt Carl L.
Published: July 2006

This study was designed to examine human subgingival plaque for the presence of dark‐pigmented Bacteroides (DPB) species in a large adult population that had been following a rigorous oral hygiene and recall program for 2 years. Subjects received scaling and root planing and oral hygiene instructions at the time of entry and then a prophylaxis and/or oral hygiene instructions at frequent intervals. Clinical measurements were determined and microbial flora identified in subgingival plaque. The DPB species were found in 63% of the subjects and 47% of the total sites. The N‐acetyl‐B‐glucosaminidase‐positive DPB species (B. melaninogenicus, B. denticola or B. loescheii), B. intermedius, B. gingivalis and strains of unclassified pigmenting Bacteroides were found in 25, 50, 3 and 40% of the subjects, respectively, and at 15, 35, 2 and 25% of the sites, respectively. Plaque and bleeding indices, probing depth and mean proportions of motile rods and spirochetes were higher at sites with DPB as compared to sites without DPB species. Sites with B. intermedius had higher plaque and gingival indices and greater loss of probing attachment than sites with DPB other than B. intermedius. The prevalence of B. intermedius and other DPB species was high even though subjects were on a rigorous oral hygiene and recall program.
Progenitor connective tissue cell populations in the gingival papilla of the rat
Authors: Render N. , Heaney T. G. , Pycock D. , West C. R.
Published: July 2006

The purpose of this study was to demonstrate the presence and anatomical positions of connective tissue progenitor cell populations in the gingival papilla of the rat. Ten male hooded Lister rats aged 4 wk were killed 1 h after flash labelling with tritiated thymidine. Paraffin sections were cut through the molar regions of 19 mandibles parallel to the occlusal plane. Sections immediately apical to the epithelium of the col and just coronal to the crest of the interdental septum (levels 1 and 5) were chosen for autoradiography, as were a further three sections (levels 2, 3 and 4), spaced equidistantly between levels 1 and 5 in a subsample of 10 of these mandibles. Mean labelling indices (LIs) for all 19 specimens were significantly higher within 5 μm of the teeth at levels 1 and 5, and in a zone 15–25 μm from the teeth in level 5. LIs for the subsample of 10 mandibles were also significantly higher within 5 μm of the teeth in levels 3 and 5, and within 15–20 μm in levels 4 and 5. Nuclear densities were highest at all levels within 10 μm of the teeth and at 20 μm (levels 1–3) or 30 Jan (levels 4 and 5) from the teeth. The data are consistent with the existence of ostensible connective tissue progenitor cell populations, one in contact with cementum and junctional epithelium, the other lying in the body of the papilla at its most apical levels, 15–25 μm from the teeth.
The effect of periodontol proteolytic Bacteroides species on proteins of the human complement system.
Authors: Schenkein Harvey A.
Published: July 2006

Proteolytic strains of Bacteroides gingivalis, Bacteroides intermedius, Bacteroides loeschii and Bacteroides denticola were assessed for their ability to inactivate select complement proteins in pooled human serum and for their effect on purified complement components C3, C4, and factor B. Under conditions of bacterial concentration resulting in limited C3 consumption in pooled serum, it was found that EDTA‐inhibitable consumption of C3, C4, and factor B occurred with nearly all strains. However, identical concentrations of B. gingivalis were also capable of inactivating purified C3, C4, and B. This property was not entirely inhibitable by EDTA. Further examination of the effect of B. gingivalis on the structure of C3 demonstrated that one strain (33277) converted purified fluid‐phase C3 to a C3b‐like molecule, while the other strain (W83) completely degraded the a‐chain of C3. In contrast, only minor cleavage of the α‐chain of C3 was apparent following incubation with B. intermedius, and no destruction of hemolytic complement activity was induced by the non‐proteolytic periodontal pathogen Actinobacillus actinomycetemcomitans. It was thus concluded that B. gingivalis is capable of proteolysis of purified complement proteins, but that the consumption of complement proteins in serum, which is completely inhibited by EDTA, is not appreciably affected by the proteolytic capacity of B. gingivalis.
Serum antibodies against the trypsin‐like protease of Bacteroides gingivalis in periodontitis
Authors: Ismaiel M. O. , Greenman J. , Scully C.
Published: July 2006

Antibody levels of IgG, IgA and IgM reactive to the trypsin‐like enzyme of B. gingivalis were measured by enzyme‐linked immunosorbent assay in serum samples from control subjects with clinically healthy gingiva, patients with adult periodontitis (AP) and patients with rapidly progressive periodontitis (RPP). Both AP and RPP patients had significantly higher levels of specific IgG and IgA antibodies than control subjects with healthy gingiva (p<0.001 in both cases). No significant difference was observed between the specific IgM antibody activity in the AP group compared to the control group. However, a significant difference was seen (p<0.01) for IgM activity in the RPP group compared to controls. The results indicate that the trypsin‐like enzyme of B. gingivalis is produced in vivo in sufficient amounts to be immunogenic to the host and particularly in patients with AP or RPP.
Collagenase activity and protein content of sulcular fluid after scaling and occlusal adjustment of teeth with deep periodontal pockets
Authors: Hakkarainen K. , Uitto V‐J. , Ainamo J.
Published: July 2006

Three teeth from each of 14 adult patients with advanced periodontitis were included in this study. The Test Tooth was an incisor or canine with increased mobility associated with an occlusal interference and a ≥ 5 mm deep pathologic pocket. The Infected Control Tooth was a non‐mobile incisor or canine with a ≥ 5 mm pocket. A non‐mobile incisor or canine with pockets ≤3 mm served as the Healthy Control Tooth. At least 7 d prior to Day 0 the patients were taught an effective oral hygiene regimen and received a supragingival prophylaxis. At Day 0, sulcular fluid for assay of protein content and Collagenase activity was collected from each chosen pocket. Immediately thereafter the Test Teeth of 7 subjects were scaled and root planed and the Test Teeth of 7 subjects occlusally adjusted. At Day 14, the treatments were reversed for the two groups. Sulcular fluid for the assays was again collected at Days 14 and 28. The protein content and collagenase activity in deep pockets was elevated during periodontitis in both mobile and immobile teeth. After establishment of a supragingivally clean oral environment, a rapid decrease of the collagenase activity took place following scaling and root planing of the root surfaces within the periodontal pockets (p≤0.05). Also, occlusal adjustment of the hypermobile teeth with deep pathological pockets reduced the protein content and collagenase activity in sulcular fluid (p ≤ 0.02). There was a further reduction of collagenase activity when occlu‐sally adjusted teeth were scaled and root planed (p≤0.02). No change in the protein content or collagenase activity was observed in the deep pockets of the untreated Control Teeth in the same patients.
Ibuprofen: An inhibitor of alveolar bone resorption in beagles
Authors: Williams R. C. , Jeffcoat M. K. , Howell T. H. , Reddy M. S. , Johnson H. G. , Hall C. M. , Goldhaber P.
Published: July 2006

The effect of the non‐steroidal anti‐inflammatory drug, ibuprofen, on the progression of periodontal disease was studied in 22 beagle dogs over a 13‐month period. Standardized radiographs were used to measure the rate of bone loss. Following a 6‐month pretreatment baseline period. 6 dogs were treated daily with 4 mg/kg ibuprofen, 5 dogs were treated with 4 mg/kg ibuprofen in a sustained release preparation, 5 dogs were treated with 0.4 mg/kg ibuprofen and 6 untreated dogs served as controls. In the untreated control dogs the rate of bone loss in the treatment period did not change significantly from baseline, although the rate was increased. In both the 4.0 mg/kg and sustained release 4.0 mg/kg ibuprofen‐treated dogs the rate of bone loss in the treatment period was significantly less than the pretreatment period rate. In the 0.4 mg/kg ibuprofen‐treated dogs the rate of bone loss, although reduced, was not significantly less than the pretreatment rate. When the rate of bone loss in the control dogs was compared with the rate of bone loss in the ibuprofen‐treated dogs, all three ibuprofen‐treated groups of dogs had significantly less bone loss than the control dogs. The untreated control dogs lost 10 teeth during the treatment period, whereas the 4.0 mg/kg and 0.4 mg/kg ibuprofen‐treated dogs lost 6 teeth and the sustained release 4.0 mg/kg ibuprofen‐treated dogs lost 2 teeth during the treatment period. The data indicate that a propionic acid derivative, the non‐steroidal anti‐inflammatory drug, ibuprofen, can significantly inhibit alveolar bone loss in beagles. Sustained release ibuprofen. which gave consistently greater blood levels over 24 h, was overall more effective.
Glomeruli in the molar gingival microvascular bed of germ‐free rats
Authors: Sims M. R. , Sampson W. J. , Fuss J. M.
Published: July 2006

TEM stereopair imaging of prepolymerized, methyl methacrylate, microvascular casts of germ‐free rats, with clinically healthy gingivae, demonstrated glomeruli in the gingivae of all molars. Glomeruli exist in the buccal, lingual and interproximal gingivae of the maxilla and mandible. Morphologically, glomeruli presented in different forms; principally as intertwining arterial and venous stalks surmounted by a multilobed glomerulus in the buccal and lingual aspects of the gingiva, and aggregations of complex glomeruli in the interproximal gingivae. Histologic examination of matched animals did not reveal any evidence of acute or chronic gingival inflammation with leukocyte infiltration. These findings provide support for the view that glomeruli develop as a normal component of the healthy gingivae and not primarily as a response to gingival inflammation.
A contrast‐correction method for digital subtraction radiography
Authors: Ohki Masafumi , Okano Tomohiro , Yamada Naoyuki
Published: July 2006

A contrast correction method for digital subtraction radiography has been developed. Optical density of radiographs was digitized into gray levels using a drum‐scanning microdensitometer with high accuracy. Gray levels of one image are converted to be equal to that of the other image using the equation obtained from gray level relations of both images. The reliability of this method was tested using radiographs of a copper step wedge which was exposed and processed under different conditions. The results show that the minimal detectable difference of the optical density was 0.04 for optimal conditions and 0.05 even for the different conditions. These indicate that the digital subtraction with contrast correction using a microdensitometer may be useful for extracting radiographic changes exclusively and it holds the potential for evaluating periodontal therapy quantitatively.
In situ activated T lymphocytes in active versus stable periodontal lesions†
Authors: Reinhardt R. A. , McDonald T. L. , Bolton R. W. , DuBois L. M. , Feely D. E. , Kaldahl W. B.
Published: July 2006

A double labeling technique was developed to detect T cell phenotype and HLA‐DR (activation) antigens on infiltrating cells in gingival biopsy sites classified as either periodontally active (≥ mm attachment loss within past 3 months), clinically similar but stable, or healthy. Serial cryostat sections were obtained from each of the above disease category biopsies in 13 periodontal maintenance patients, and were processed with sequential Leu series (T cell subsets) avidinbiotin‐peroxidase followed by anti‐HLA‐DR indirect alkaline phosphatase labeling protocols. Labeled cells were counted in repeatable fields in the sulcular, middle and oral thirds of each section, and HLA‐DR+ T cells (activated) were calculated. Total HLA‐DR‐labeled cells and HLA‐DR‐positive pan‐T cells and T helper cells (Th) were all more numerous in active specimens than in healthy sites (p<0.05), and in sulcular fields than in the oral third of the section (p<0.05). Although activated T suppressor cell (T5) densities did not vary statistically according to tissue location, active biopsies had more cells per field than either stable or healthy specimens (p<0.05), especially in the sulcular third. A majority of pan‐T, Ts and Th cells appeared to display activation markers in active, stable and healthy biopsies. This study supports the functional role of T lymphocytes in modulating the immune response in periodontal tissues.
Effects of race and periodontal status on antibody reactive with Actinobacillus actinomycetemcomitans strain Y4
Authors: Gunsolley J. C. , Tew J. G. , Gooss C. M. , Burmeister J. A. , Schenkein H. A.
Published: July 2006

Higher levels of serum antibody reactive with Actinobacillus actinomycetemcomitans strain Y4 (AAY4) have been demonstrated in localized juvenile periodontitis than in other forms of periodontal diseases. However, in studies which reported the racial distribution of the clinical groups, a predominantly black juvenile periodontitis population has been compared with a non‐periodontitis control population that was predominantly white. The purpose of this study was to determine the effect of race (black or white) on antibody reactivity to AAY4 for subjects with clinical diagnoses of adult periodontitis (AP), non‐periodontitis (NP), juvenile periodontitis (JP) and severe generalized periodontitis in young adults (SP). A radioimmunoassay (RIA) was utilized to detect and quantitate antibody to AAY4. Within clinical groups of NP, JP and SP a higher prevalence of seropositive black subjects than white subjects was found. The association between a high prevalence of positive antibody responses to AAY4 in JP subjects compared to NP subjects still exists, but was reduced compared to previous reports. White non‐periodontitis subjects, used as control subjects in previous reports, were found to have a significantly lower frequency of seropositivity to AAY4 than black non‐periodontitis subjects. This relationship held whether the periodontatly healthy subject was ascertained from a family with a JP or SP family member or was ascertained solely on the basis of a diagnosis of non‐periodontitis. The difference in the prevalence of seropositivity to AAY4 between JP and SP subjects was entirely due to the racial composition of the two groups, as nearly half the SP subjects were white compared with only 15% of the JP subjects. Thus, antibody reactivity to AAY4 was found to be related to both clinical diagnosis and race.
Production of chemotactic factors for neutrophils following the interaction of Bacteroides gingivalis with purified C5
Authors: Schenkein H. A. , Berry C. R.
Published: July 2006

The aim of this study was to determine whether complement‐derived chemotactic factors are produced following the interaction of B. gingivalis with purified C5 protein. B. gingivalis strain ATCC 33277 was incubated with purified human C5 under anaerobic conditions; assay of the supernatants by SDS‐PAGE demonstrated proteolysis of C5 protein and functional hemolytic assay demonstrated inactivation of C5 activity. Supernatants were then tested for chemotactic activity for PMN's in the modified Boyden chamber, and for the presence of C5a des Arg by specific radioimmunoassay. It was noted that increased bacterial concentrations produced increased concentrations of immunoreactive C5a des Arg, and that PMN chemotactic activity was observed in the reaction mixtures. In contrast, the non‐proteolylic pathogen Actinobacillus actinomycetemcomitans Y4 failed to cleave C5 or to generate chemotactic activity from C5. When C5 was incubated with B. gingivalis under conditions resulting in maximal generation of chemotactic activity and supernatants were reacted with IgG fractions of goat anti‐C5, chemotaxis was inhibited; similar treatment of FMLP with a‐C5 failed to inhibit FMLP‐induced chemotaxis. Therefore, B. gingivalis is capable of producing C5 derived chemotactic activity by direct interaction with purified C5.
Blastogenic response and immunoglobulin production by inflamed gingival lymphocytes from dogs
Authors: Yamashita K. , Ohfuji Y. , Yoshie H. , Hara K.
Published: July 2006

The present study evaluated blastogenic responses and immunoglobulin production (IgG, IgM) by inflamed gingival lymphocytes from dogs. The excised tissues were cut finely, digested in collagenase for 60 min, then passed through a mesh, teased with a 24 G needle several times and centrifuged over a ficoll gradient. Responses to PHA, Con‐A and PWM were assessed using peripheral blood lymphocytes (PBLs) and submandibular lymph node cells (SNLs) as controls. Blastogenesis was evaluated from the uptake of 3H‐thymidine and the presence of IgG and IgM in culture supernatants was quantified using ELISA. The extraction procedure resulted in a mean 2.09 ± 0.44 × 105 lymphocytes per 100 mg tissue (wet weight). These cells had a mean viability of 84.4 ± 3.0%. The responses of PBLs and SNLs to PHA, Con‐A and PWM were substantial, as expected, while the responses of gingival lymphocytes to any mitogen remained at the level of unstimulated lymphocytes. However, gingival lymphocytes produced and secreted IgG and IgM. IgG production by gingival lymphocytes was elevated when compared with those of PBLs and SNLs, while IgM production by gingival lymphocytes was less than PBLs and SNLs. The responses of PBLs and SNLs are not parallel to the response of gingival lymphocytes.
Purification and characterization of Eikenella corrodens aggregating factor from submandibularsublingual saliva
Authors: Ebisu Shigeyuki , Fukuhara Hironobu , Okada Hiroshi
Published: July 2006

Eikenella corrodens 1073, which has been shown to induce periodontal disease in experimental animals, was found to aggregate when mixed with human submandibular‐sublingual (SM‐SL) saliva. The purpose of this study was to isolate, purify and chemically characterize the substance that agglutinates E. corrodens cells (E. corrodens aggregating factor [Ec‐AF]). Ec‐AF was detected in SM‐SL saliva of all the donors tested, whereas E. corrodens aggregating activity was not detected in parotid saliva. Ec‐AF was purified from SM‐SL saliva by ECTEQLA‐cellulose column chromatography, ultrafiltration and gel filtration high performance liquid chromatography. An 81‐fold increase in the specific activity of purified Ec‐AF was achieved with a yield of 16.7%. Polyacrylamide gel electrophoresis of Ec‐AF in sodium dodecy) sulfate and β‐mercaptoethanol produced a single protein band corresponding to a subunit molecular weight of 140 000. Treatment of an identical gel with periodic acid‐Schiff reagent resulted in staining only of material coinciding with the Coomassie blue‐staining band, indicating that the Ec‐AF was a glycoprotein. Chemical analysis indicated that Ec‐AF is composed of protein (27.3%), neutral sugars (30.3%), hexosamines (24.9%), and sialic acid (17.3%). The polypeptide backbones of Ec‐AF contained 33% serine plus threonine and 36% proline plus alanine. The carbohydrate moety of Ec‐AF consisted of N‐acetylgalactosamine, galactose, fucose, sialic acid, N‐acetylglucosamine, with their molar ratio being approximately 2:2:1:1:1, respectively.
Host modulation of adherence of oral bacteria: the effect of human neutrophil myeloperoxidase on the attachment of Actinomyces viscosus and Actinomyces naeslundii to saliva‐coated hydroxyapatite
Authors: de Camargo Paulo M. , Miyasaki Kenneth T. , Wolinsky Lawerence E.
Published: July 2006

Host neutrophils, by virtue of their ability to secrete lysosomal enzymes and reduced oxygen metabolites, may play a fundamental role in altering the composition and pathogenic potential of dental plaque by modulating bacterial adherence. The adherence of Actinomyces viscosus and Actinomyces naeslundii to salivacoated surfaces is known to be saturable and mediated by proteinaceous fimbriae. In this study, we examined the abhesive effects of the human neutrophil enzyme, myeloperoxidase (MPO), on the adherence of A. viscosus T14V and A. naeslundii ATCC 12104 to saliva‐coated hydroxyapatite (SHA) beads. Microorganisms were treated with MPO in the presence of hydrogen peroxide (H2O2) and physiologic concentrations of chloride (forming the MPO‐H2O2‐Cl‐ system) and incubated with SHA beads. Treatment of cells with the isolated MPO‐H2O2‐C1‐ system reduced the percentage of cells that bound. This abhesive effect was inhibited by sodium azide, exogenous catalase, taurine, and potassium thiocyanate. The three major chromatographic forms of MPO (I, II, and III) were effective in blocking adherence of A. viscosus. We conclude that the MPO‐H2O2‐Cl‐ system can interfere with the adherence of A. viscosus and A. naeslundii, and therefore may be important in modulating the microbiai colonization of oral surfaces.
Periodontal ultrasonic diagnosis: experiments on thin bony platelets and on a simulated periodontal ligament space
Authors: Löst C. , Nüssle W.
Published: July 2006

In this study we tried to determine whether it is fundamentally possible to image the periodontal ligament space over the buccal and lingual root surface in the ultrasonic graph. The imaging of the space is an essential requirement for the exact determination of the thickness of the facial or oral alveolar bony plate. In addition, the clear visual differentiation of bone and root enables an exact and reliable determination of the contour of the facial alveolar crest. The following devices were used:—a digital ultrasound imaging system developed on the basis of many preliminary experiments;—three high‐resolution transducers which can theoretically display a space width of 0.2 mm. Studies were performed on bone specimens and on a simple model of the periodontal space ideal for ultrasonic experiments. It was shown that the ultrasonic pulses emitted by the transducer can penetrate plane parallel‐cut bony platelets which are up to 2 mm thick. Aside from this, we succeeded in acquiring a resolved image of each interface of very thin bony platelets (minimum 0.12 mm). In another series of experiments the sonographic representation of simulated periodontal spaces having clinically relevant dimensions is demonstrated on an ideal model.
Distribution of 3H‐fucose in the transseptal ligament of the mouse
Authors: Johnson Roger B.
Published: July 2006

The present study demonstrated 3H‐fucose distribution in three regions of the transseptal ligament; the middle, mesial (adjacent to the first molar tooth) and distal (adjacent to the second molar tooth) thirds; of 6‐week‐ and 6‐month‐old Swiss mice. Incorporation of the isotope was rapid and maximal peaks occurred at 3 hours in most regions of 6‐month and at 12 h in most regions of 6‐wk animals: highest grain counts were over the middle third of the ligament of 6‐wk animals (p<0.001). During incorporation, mean grain counts were significantly different as a function of age (p<0.001), region (p<0.01) and time (p<0.001) and there was a significant interaction between region and time (p<0.005). Grain removal occurred at a slower rate: there were significant differences in mean grain counts as a function of age (p<0.001), region (p<0.001) and time (p<0.001) and a significant interaction between time and region (p<0.001) and between time, region and age (p<0.001). The highest rate of grain removal was in the middle third of the ligament of 6‐wk animals. Half‐life of labeled glycoproteins was shortest in the ligament of 6‐wk animals. The study suggested regional differences in metabolism of fucose‐containing glycoproteins of the transseptal ligament: highest turnover rates in the 1) middle third, and 2) young animals.
Evaluation of test statistics in split‐mouth clinical trials
Authors: Hujoel P. P. , Moulton L. H.
Published: July 2006

This study was undertaken to examine the appropriateness of test statistics used for split‐mouth clinical trials. Twenty‐two published trials were reviewed and the primary test statistics were labeled as appropriate, inappropriate, or absent. Only 5 of the 22 trials reported an appropriate test statistics. Of the remaining 17 trials, 12 used an inappropriate test statistics, and 5 did not report or did not use statistical tests. A serious problem is that more than half of the reviewed trials have reported the use of a one‐way analysis of variance or a two‐sample t test to investigate the data of the split‐mouth trial. This mistake may have led to a large increase of the Type II errors due to the correlated nature of split‐mouth data. Failure to detect genuine therapeutic differences because of inadequate attention to the data analysis can occur with inappropriate use of test statistics. It is concluded that there should be more concern for the use of appropriate test statistics.
Flurbiprofen treatment of human periodontitis: effect on alveolar bone height and metabolism
Authors: Jeffcoat M. K. , Williams R. C. , Reddy M. S. , English R. , Goldhaber P.
Published: July 2006

The effect of the non‐steroidal anti‐inflammatory drug, flurbiprofen, in reducing periodontal disease activity was assessed in 15 patients with periodontitis. Eight patients received 50 mg flurbiprofen b.i.d. for 2 months, and 7 patients received placebo in this double‐blind study. Alveolar bone height was determined using standardized radiography and alveolar bone metabolism was assessed using 99m‐Tc‐uptake prior to dosing and 2 months later. Radiopharmaceutical uptake was significantly reduced in the alveolar bone of teeth undergoing active bone loss at the start of the study in patients receiving flurbiprofen (p<.04), whereas no significant change was observed in the placebo‐treated patients. There was significantly less bone loss during the 2‐month study period in the flurbiprofen‐treated patients when compared to the placebo‐treated patients (p< .02). These results indicate that flurbiprofen administration may affect bone metabolism and reduce bone loss in patients with periodontitis.
Comparison of interstitial collagenases from human gingiva, sulcular fluid and polymorphonuclear leukocytes
Authors: Sorsa Timo , Uitto Veli‐Jukka , Suomalainen Kimmo , Vauhkonen Matti , Lindy Seppo
Published: July 2006

Mammalian collagenases (EC 3.4.24.7) have been suggested as playing an essential role in the initiation of the collagen degradation in periodontal diseases. Two distinct types of interstitial collagenases have been characterized in vertebrate tissues. These enzymes, the fibroblast‐ and the neutrophil‐type collagenases, differ in molecular weight and antigenic properties, as well as substrate specificity and mechanism of activation. In order to determine the cellular origin and mode of action of collagenase in periodontal tissue, we studied the molecular size, the substrate specificity and the activation of collagenases partially purified from inflamed human gingival extracts, sulcular fluid, gingival explant culture medium and polymorphonuclear leukocytes (PMN). Types I, II and III collagens used as substrates were purified from bovine tendon, cartilage and amnion membrane, respectively. Apparent molecular weights of 70–75 k were obtained for gingival extract, sulcular fluid and PMN collagenases and 45 k for gingival explant culture collagenase by gel filtration technique. The gingival extract and sulcular fluid collagenases as well as PMN collagenase could be activated by gold thioglucose and gold thiomalate: no activation of gingival explant culture collagenase was noted. The gingival extract collagenase, sulcular fluid collagenase and PMN collagenase degraded preferentially types I and II collagens relative to type‐III collagen. In contrast, gingival explant culture collagenase degraded preferentially types I and III collagens relative to type‐II collagen. The results indicate that collagenase in extracts of inflamed human gingiva and in sulcular fluid during inflammation is mostly derived from PMN cells. On the other hand, collagenase produced by gingival explants in culture is probably synthesized by fibroblasts.
Comparison of NK‐cell (Leu‐7 + and Leu‐11b +) populations in clinically healthy gingiva, chronic gingivitis and chronic adult periodontitis
Authors: Cobb Charles M. , Singla Om , Feil Philip H. , Theiesen Frank C. , Schultz Rudane E.
Published: July 2006

Various investigations have reported the presence of cytotoxic lymphocyte activity in inflammatory periodontal disease. The collective evidence indicates that the inflammatory infiltrates of gingivitis and periodontitis should feature a major component of large granular lymphocytes (NK‐cells) possessing cytotoxic potential. Thus, the purpose of this study was to determine and compare, by use of immunohistochemical methods, the numbers of NK‐cells in biopsies of clinically healthy gingiva, chronic gingivitis and chronic adult periodontitis and their relationship, if any, to the T and B‐lymphocyte populations. Gingival biopsies were obtained from 8 patients in each of three disease groups selected on the basis of predetermined clinical criteria. Using the avidin‐biotin immunoperoxidase technique, four consecutive serial sections from each biopsy specimen were stained with a panel of antihuman monoclonal antibodies for T‐lymphocytes (UCHL‐l) B‐lymphocytes (CD‐45R), and NK‐cells (Leu‐7 and Leu‐11b). Analyses of variance yielded a statistically significant main effect for each cell immunophenotype. The Newman‐Keuls Sequential Range Test showed statistically significant differences for all but two mean comparisons (p < 0.01). The comparisons for UCHL‐1 and Leu‐7 between chronic gingivitis and periodontitis specimens did not demonstrate significance. Although T and B‐lymphocyte populations increased approximately 20 × progressing from healthy to gingivitis to periodontitis specimens, the NK‐cell population showed only a 3 × increase which represented 19%, 6.6% and 7% of the total of all positively stained lymphocytes across biopsy groups.
Effect of x‐ray beam vertical angulation on radiographic alveolar crest level measurement
Authors: Hausmann E. , Allen K. , Christersson L. , Genco R. J.
Published: July 2006

Utilizing intraoral radiographs of human skulls taken at known vertical angulation, we have demonstrated that expression of the crest level as a distance between cej and the crest is as accurate as a ratio of bone height to root length. The degree of inaccuracy of either of these measures is related to the magnitude of the angular deviation of the x‐ray beam from 90°. Angular deviation can be estimated from calculation of a cusp height score (ratio of lingual cusp height to buccal cusp height × 100). Based on the analysis of cusp height scores it was determined that the x‐ray beam angulation for posterior bitewings ranged between 90° and 80° whereas for posterior periapicals the angulation range was between 90° and 70° Therefore, it is recommended that, for longitudinal studies of bone height, measurements of the crest to cej distance, particularly in the region of the molars, be made utilizing bitewing radiographs. For the premolar and incisor regions, deviation of the vertical angulation of an x‐ray of up to 20° from a 90° baseline resulted in little, if any, change in crest level by either one of the two measures used. An appendix is provided for the theoretical modeling of the types and magnitude of change in crest level observed for projection images of different anatomical configurations.
Tryptase‐like activity in crevicular fluid from gingivitis and periodontitis patients
Authors: Cox S. W. , Eley B. M.
Published: July 2006

Crevicular fluid was collected from gingivitis and periodontitis patients on filter paper strips and then eluted into buffer. The eluates hydrolyzed ZAlaArgArgAFC at alkaline pH and the effector response at pH 8.5 indicated serine proteinase activity. The results, particularly the substantial increase in activity produced by heparin, were suggestive of mast cell tryptase. They were also consistent with the properties of the tryptase‐Iike enzyme identified in extracts of inflamed human gingiva (Cox and Eley, Arch Oral Biol, in press). Partial inhibition of crevicular fluid eluate activity by soybean trypsin inhibitor suggested the additional presence of a second trypsin‐like enzyme which might be of host or bacterial origin.
The relationship between connective tissue and its microvasculature in the healthy dog gingiva
Authors: Nobuto Takahiro , Tanda Hiromi , Yanagihara Kazuaki , Nishikawa Yoshihiro , Imai Hisao , Yamaoka Akira
Published: July 2006

The morphological consistency of subepithelial connective tissue and its vascular architecture was studied in the healthy gingiva of adult mongrel dogs. Corrosion‐cast specimens of the vasculature and specimens of well‐separated connective tissue from the lamina propria were observed by SEM. Specimens injected with india ink also were examined employing light microscopy. Summarizing the results: 1) Beneath the buccal gingival epithelium, short conical papillae were seen in the subepithelial connective tissue. The capillary structure throughout this region was basically of the loop type, the overall appearance of which replicated the papillae. The papilla disappeared at the muco‐gingival junction, so that after the transition to the alveolar mucosa, no papillary formation was observed. The vasculature had transformed from loop to network structure. 2) Beneath the sulcular gingival epithelium, the subepithelial connective tissue displayed a smooth concavity with no papillae. In this region, the capillaries formed a flat, dense network in accordance with the morphology of the connective tissue. The capillary network suddenly disappeared at the terminal edge of the inner epithelium. The vessels of the lamina propria located immediately beneath the network reduced their lumina at the margin and formed the plexus of the periodontium, displaying a rather open network.
The effects of beam hardening on digital subtraction radiography
Authors: Webber R. L. , Tzukert Arlk , Ruttimann Urs
Published: July 2006

Quantitative assessment of osseous changes attributable to periodontal disease is made possible by digital subtraction radiography. Tissues through whjch x rays travel to produce dental radiographs essential to this process alter the energy spectrum of the beam such that calibration errors result when densitometry is attempted using a homogeneous calibration standard such as a step wedge. The following controlled in vitro investigation evaluates the extent of such errors caused by these spectral differences, called beam hardening. Simulated osseous lesions of known size were computed densitometrically using selectively filtered radiation to produce the x‐ray images. The resulting data confirm the theory and demonstrate with statistically meaningtul accuracy that beam hardening can contribute a significant component of variance to absolute estimates of lesion size. They also suggest that other errors (probably attributable to low contrast) may be even more important at high peak kilovoltages.
Reduction of dental plaque formation by chlorhexidine dihydrochloride lozenges
Authors: Kaufman Arieh Y. , Tal Halm , Perlmutter Shemuel , Shwartz Marian M.
Published: July 2006

The effect of chlorhexidine dihydrochloride (chlorhex HCl) in lozenges on plaque growth was assessed on 21 subjects with fresh plaque of 7 days duration. The lozenges, which contained 5 mg chlorhex HCl, were sucked three times daily after meals, for 2 weeks. The study was a single‐blind crossover. Placebo lozenges had all the ingredients except chlorhex HCl, These were used as a control. Results indicated that lozenges containing chlorhex HCl were a potent plaque inhibitor. The mean plaque score was reduced by 62.8% from an initial mean plaque score (DO) of 2.38 ± 0.48 to (D7) 0.89 ± 0.26 (p < 0.0001), after 1 wk of usage. A further reduction to plaque score (DI4) of 0.56 ± 0.27 (p < 0.0001) was recorded by theend of the 2nd wk. Usage of the placebo during the same time period did not show significant differences in the plaque score (DO=2.38; D7=2.33; D14=2.42). Inhibition of plaque formation to the 1104 test surfaces revealed a total elimination of the higher levels of plaque (scores 4 and 5), a considerable reduction of the middle levels (scores 2 and 3) and a significant increase (44.7%) of low level plaque (score 1). Total elimination of plaque (score 0) was observed in 50.3% of the test group surfaces. Lozenges containing 5 mg chlorhexidine dihydrochloride, taken three times daily, were an efficient, comfortable and potent agent for reducing and inhibiting plaque formation. These lozenges are a more convenient alternative to chlorhexidine moulhrinses and may prove to be superior to these.
Changes in cyclooxygenase metabolities in experimental periodontitis in Macaca mulatta
Authors: Offenbacher S. , Odle B. M. , Braswell L. D. , Johnson H. G. , Hall C. M. , McClure H. , Orkin J. L. , Strobert E. A. , Green M. D.
Published: July 2006

The four principal metabolites of cyclooxygenase (CO) were examined during the progression of experimental periodontitis in the rhesus monkey Macaca mulalla. Thirty‐two monkeys were divided in four disease‐matched groups. Three groups were treated with flurbiprofen a potent CO inhibitor, at either 0.027, 0.27 or 7.1 mg/kg/day delivered systemically by a subcutaneously‐implanted osmotic mini‐pump. We have previously described the findings indicating that flurbiprofen treatment significantly retarded clinical attachment loss (ALOSS), redness and radiographic bone loss (BLOSS). This investigation focuses on the changes in CO metabolites which occur during disease progression of ligature‐induced periodontitis and on the dose‐response relationship of flurbiprofen, as it relates to disease inhibition and the suppression of ARA metabolites within the crevicular fluid (CF). In untreated animals there was a statistically significant 3‐fold increase in CF levels of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) at 3 months, as compared to baseline, which positively correlated with increases in redness, bleeding, ALOSS and BLOSS. CF‐PGE2 and TxB2 levels reached a 6‐fold peak at 6 months and returned to baseline by 12 months. Flurbiprofen (Fb) prevented the 3‐month rise in TxB2, but did not affect the increase in PGE2. At 6 months, Fb administration caused a dosedependent inhibition of both PGE2 and TxB2. Probit analysis of the doseresponse data revealed that the concentration of Fb which caused a 50% inhibition of CF‐TxB2 level (the IC50 value for TxB2 synthesis) was approximately two logs lower than the IC50 value for PGE2 synthesis, i.e. TxA2‐IC50= 0.013 vs. PGE2‐IC50 1.35 mg flurbiprofen/kg/d. The slopes of the PGE2, and TxB2 inhibition curves were identical, consistent with a similar mechanism or singular enzyme for the site of action of Fb inhibition of CO activity. However, the kinetics and sensitivity of Fb inhibition were significantly different for the CO activity responsible for TxB2 and PGE2 synthesis, perhaps due to different compartmentalization of CO within different cell types.
The effect of a dentifrice containing zinc citrate and Triclosan on developing gingivitis
Authors: Saxton C. A. , van der Ouderaa F. J. G.
Published: July 2006

A partial mouth experimental gingivitis model was employed to establish the potential efficacy of a dentifrice containing a zinc salt and the antimicrobial agent Triclosan to prevent or delay the development of gingivitis over a period of 28 days. Initially, gingival health was established in 34 subjects following a 6‐week period of professional tooth cleaning and oral hygiene instruction. A toothshield was constructed to fit 4 posterior mandibular teeth. Undiluted test or placebo dentifrice was applied to the experimental teeth via the tooth shield, which also prevented plaque removal from these teeth during habitual brushing of the remainder of the dentition. The presence of plaque, bleeding after probing and visual signs of inflammation were independently assessed. Plaque accumulated rapidly and gingivitis developed in both groups. At the 2‐wk assessments, lower mean plaque scores were recorded for the group using the test dentifrice. At the 4‐wk assessment a significantly lower level of gingivitis was recorded for the test group. It is concluded that (a) the model can be used to establish the potential efficacy of a dentifrice to maintain gingival health, (b) the dentifrice containing zinc citrate and Triclosan was efficacious and (c) the Gingival Index possibly overestimates the proportion of healthy gingival sites.
Analysis of the serum antibody responses to type 1 and type 2 fimbriae in mice immunized with Actinomyces viscosus T14V
Authors: Haber* Jerome , Grinnell Christine
Published: July 2006

The antibody responses of inbred mice immunized with Actinomyces viscosus T14V cells were analyzed using enzyme‐linked immunoabsorbent assays (ELISAs) for measuring serum antibodies reactive with A. viscosus Tl4V cells and type 1 and type 2 fImbriae. In A/I mice immunized intraperitoneally on days 0 and 14, the serum antibody responses approached peak levels during d 19–35, and a dose of 108 cells/injection elicited optimal responses. Analysis of the responses of three genetically diverse strains of inbred mice indicated striking variations in the amounts of anti‐type 1 (6.5‐fold) and anti‐type 2 (14.3‐fold) antibodies elicited. The observed variations in the magnitude of the anti‐fImbrial antibody responses are theoretically of sufficient magnitude to account for signifIcant differences between mouse strains in their ability to inhibit adherence of A. viscosus T14V to saliva‐coated hydroxyapatite and other bacteria. These studies provide a model with which the effects of variations in anti‐fimbrial antibody responses on bacterial adherence may be analyzed.
Microbiota and crevicular fluid collagenase activity in the osseointegrated dental implant sulcus: A comparison of sites in edentulous and partially edentulous patients
Authors: Apse P. , Ellen R. P. , Overall C. M. , Zarb G. A.
Published: July 2006

The soft tissues adjacent to osseointegrated dental implants (OII) were investigated using clinical, biochemical and microbiological methods. Tooth and implant crevices were compared in 15 partially edentulous patients, examining 28 peri‐implant and 19 periodontal sites, and in 6 edentulous patients, examining 13 implant sites. Sites were classified by standard periodontal indices; the crevicular fluid flow determined; crevicular fluid was collected for collagenase assays; and the subgingival bacterial flora was examined and cultured. Differences in clinical parameters were noted in that implants had significantly less keratinized gingiva and deeper probing depths. Crevicular fluid was present in the OII sulcus but the crevicular fluid flow did not differ from that observed from tooth sites either in the partially edentulous or edentulous patients. Tissue collagenase activity and collagenase inhibitor were detected in the implant crevicular fluid and, as in periodontal sites, a strong inverse relationship was found between the levels of active collagenase and collagenase inhibitor. Microbiology included darkfield microscopy, anaerobic culturing for total colony forming unit counts and identification of black pigmented Bacteroides (BPB). Few differences were observed between implants and teeth in partially edentulous patients, indicating that crevices around teeth may act as reservoirs of bacteria which can colonize implant sites. A higher percentage of BPBs and wet spreaders (Capnocytophaga) was noted at partially edentulous implant sites when compared with edentulous implant sites, perhaps reflecting the lower numbers of periodontal pathogens present in edentulous mouths. Overall, the characteristics of implant sulci appear to be similar to periodontal sulci with respect to crevicular fluid flow and microflora.
T cells and T‐cell subsets in periodontal diseases
Authors: Meng Huanxin , Zheng Linfan
Published: July 2006

Acetone‐fixed cryostat gingival tissue sections from marginal gingivitis (MG), juvenile periodontitis (JP), adult periodontitis (AP) patients and clinically healthy subjects (H) were immunohistochemically stained with monoclonal antibodies to aid in identification and quantification of T cells and T‐cell subsets in the inflammatory infiltrates. T cells were present in all specimens studied. The number of T cells in the connective tissue (CT) zone of AP was much greater than in any other groups. The amounts of T cells in oral epithelium and sulcular (pocket) epithelium zones of diseased groups were larger than in the healthy group. There was a significant positive correlation between the number of T cells and the percentage of infiltrated connective tissue. While there were no significant differences between the mean ratios of T‐helper/T‐suppressor cells from diseased and healthy tissues, large individual variance existed in the three diseased groups. The existence of a high or low T4/T8 ratio in inflamed gingiva might be related to an abnormal immunoregulation.
Saccharide residues in human gingiva as revealed with fluorochrome‐coupled lectins
Authors: Hormia M. , Virtanen I.
Published: July 2006

The histochemical binding of 16 fluorochrome‐conjugated lectins to human marginal gingiva was investigated. Of a total of 14 galactose/N‐acetylgalactosamine (Gal/GaINAc)‐specific lectins, Dolichos biflorus (DBA), Helix pomatia (HPA), and Helix aspersa agglutinins (HAA) were blood group A‐reactive whereas Griffonia simplicifolia I‐B4 (GSA‐I‐B4) and Sophora japonica (SJA) agglutinins were blood group B‐reactive. HPA, HAA and GSA‐I‐B4 bound to all suprabasal epithelial cells and to vascular endothelia in tissues with compatible blood groups and detected only upper epithelial cells in tissues lacking the respective blood group antigens. SJA, on the other hand, bound to suprabasal epithelial cells and to endothelial cells in specimens from blood group B, AB and A individuals. DBA gave a heterogeneous labeling of upper epithelial cells in blood group A, AB and B specimens but not in O specimens and did not react with endothelia in any of the tissue samples. DBA bound, instead, consistently to mast cells in gingival lamina propria. Of the other Gal/GalNAc‐reactive lectins, 2 bound to suprabasal epithelial cells and 7 to all viable cell layers in gingival epithelium. The binding of these lectins was blood group‐independent. Of the fucose‐specific lectins, Ulex europaeus agglutinin I (UEA‐I) gave an intense suprabasal cell membrane‐type of epithelial fluorescence in blood group O specimens and a more diffuse staining in other specimens and recognized endothelial cells in a blood group‐independent way. Anguilla anguilla agglutinin (AAA) gave a blood group‐independent epithelial staining and bound hetero‐geneously to endothelial cells only in blood group O samples. Neuraminidase digestion uncovered fucose, Gal and GalN Ac residues, some of which were blood group‐related. The results of the present study show that, in gingival epithelium, various cellular domains may express different terminal saccharide moieties. The pattern of glycosylation is, however, not strictly related to the maturity of the cells but depends to some extent on the blood group status of the tissue donor.