bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphometric analysis of the intercellular space and desmosomes of rat junctional epithelium
Authors: Hashimoto Sadamitsu , Yamamura Takeo , Shimono Masaki
Published: July 2006

To elucidate the biological characteristics of the junctional epithelium (JE) in rats, ultrastructural and morphometric studies of the gingiva in the maxillary molar regions were carried out. Morphometric analysis of three different regions of the JE and the oral epithelium (OE) led to the following results. In the apical JE, intercellular space accounted for about 23% of the total epithelial tissue. At the connective tissue interface, the space accounted for 17% of total epithelial tissue. At the enamel interface, the space accounted for 35% of total JE tissue. A large number of leukocytes were detected in the enlarged intercellular spaces. In the OE, the space accounted for about 11%. In the apical region of the JE. desmosomes occupied approximately 5% of the plasma membrane perimeter; in both the enamel and connective tissue, about 3%; and in the OE, about 5%. However, desmosome densities were approximately 14/100 μm2 in the JE. while being approximately 66/100 μm2 in the OE. From these results, it is suggested that: (a) the volume of intercellular space relative to the entire JE coincides with a dynamic migration of the epithelium; (b) enlargement of the intercellular spaces in the JE causes a low incidence of desmosomes: (c) there is no physiological permeability barrier in the JE; and (d) abundant leukocytes in the intercellular spaces may play an important role in obstructing the passage of external bacteria and toxins into the tissue.
Citric acid conditioning of roots affects guided tissue regeneration in experimental periodontal wounds
Authors: Pettersson E. C. , Aukhii I.
Published: July 2006

The effect of citric acid conditioning of roots on the formation of a new connective tissue attachment was evaluated in the presence of a selective cell population. Fenestration wounds of standard sizes were made on the buccal aspects of mandibular premolars in 6 beagle dogs. The exposed root surfaces were curetted thoroughly and conditioned with citric acid (experimental) or distilled water (controls) for 3 minutes. The wounds were covered with Millipore filters to facilitate population of curetted root surfaces by cells from the adjacent periodontal ligament. Histologic analysis was made after 3 months of healing.

The extent of new connective tissue attachment varied in both the experimental and control specimens. The percentage of surgically denuded root surface showing new cementum with inserting fibers was significantly lower in the experimental group compared with the controls. Root resorption was seen in both experimental and control specimens but involved a significantly larger percentage of denuded root surface in the experimental specimens. Ankylosis occurred more frequently in the experimental group compared with the controls, while no difference was seen in the degree of bone regeneration.

The results indicate that new connective tissue attachment can form on denuded root surfaces by a selective cell population. Citric acid conditioning of roots appears to either delay or complicate healing in the presence of a selective cell population.
Healing following implantation of partially‐demineralized roots in palatal connective tissue
Authors: Aukhil I. , Suggsand C. , Pettersson E.
Published: July 2006

The present study examined the healing following implantation of partially‐demineralized roots in palatal connective tissues in beagle dogs. The maxillary second premolars were extracted, the roots planed thoroughly, superficially demineralized in citric acid (pHl) and implanted as pairs in palatal connective tissues. Histologic examination was made after 3 months of healing. Transverse sections revealed three types of healing at the root‐soft tissue interface: connective tissue encapsulation/adhesion, root resorption and ankylosis. New cementum and inserting oriented fibers were not seen in any of the specimens examined. In the present wound model, partial demineralization of roots with citric acid does not appear to promote connective tissue attachment in vivo.
Plaque levels in relation to the number of toothbrushing strokes in uninstructed English schoolchildren
Authors: Macgregor I. D. M. , Rugg‐Gunnand A. J. , Gordon P. H.
Published: July 2006

y‐seven children, aged 13 yr, were asked to brush their teeth in school and were unaware that their toolhbrushing was being recorded on tape. Plaque levels [Plaque Index] were recorded after brushing. By repealed viewing of the tapes on a monitor, the total brushing time and the number of brushing strokes used in each of 12 areas of the dentition were obtained. The mean total brushing time (±SD) was 51.1 s (±15.4). The number of brushing strokes used in each of the 12 areas of the mouth varied widely, both within and between areas, and correlated poorly with plaque levels after brushing. In only one area (maxillary right posterior buccal) was a statistically significant negative correlation observed, and less plaque (p<0.05) found in subjects who brushed this area with > 10 strokes compared with subjects who brushed with < 10 strokes. This study emphasises the need for proper toodibrushing instruction in schoolage children.
Proportions and identity of IgA1‐degrading bacteria in periodontal pockets from patients with juvenile and rapidly progressive periodontitis
Authors: Frandsen Ellen V. G. , Theilade Else , Ellegaard Birgit , Kilian Mogfns
Published: July 2006

Degradation of immunoglobulin A1 (IgAl) has previously been demonstrated in suspected periodontal pathogens. The present study revealed that a considerable proportion of the microbial flora in periodontal pockets of patients with juvenile periodontitis (median 29%) and rapidly progressive periodontitis (median 27%) was capable of degrading IgAl. Four different types of degradation occurred: Complete degradation of IgAl; extensive degradation leaving the Fc part of the molecule intact; traditional IgAl protease activity yielding intact Fc and Fab fragments, and removal of carbohydrate side chains on the IgAl molecule. Apart from species already known to degrade IgAl. IgAl protease was, for the first time, demonstrated in strains of Veillonella spp. The ability to cleave off carbohydrate side chains was a feature of a wide variety of bacteria belonging to the species Streptococcus sanguis, S. mitior, S. milleri, Veillonella spp., Actinomyces naeslundii. A. viscosus. Arachnia propionica, and Bacterionema matruchotii. The ability of subgingivally colonizing bacteria to degrade IgA may be a factor contributing to aggravation and perpetuation of the inflammatory reaction in the periodontal tissues.
Flurbiprofen treatment of periodontal disease in beagles
Authors: Jeffcot M. K. , Williams R. C. , Wechter W. J. , Johnson H. G. , Kaplan M. L. , Gandrup J. S. , Goldhaber P.
Published: July 2006

The effect of the non‐steroidal anti‐inflammatory drug flurbiprofen on the progression of periodontal disease was studied in 12 beagle dogs over a 2‐yr period. Standardized radiographs were used to measure the rate of bone loss; bone‐seeking radiophormaceutical uptake was used to assess the effect on bone metabolism, and gingival inflammation was scored. Following a 6‐month pretreatment baseline period. 6 dogs were dosed daily with 0.02 mg/kg flurbiprofen for a 12‐month treatment period. Also, one side of the mouth in each dog was treated with periodontal flap surgery at the beginning of the treatment period. After 12 months, flurbiprofen was discontinued and the dogs were studied for a 6‐month post‐treatment period. In flurbiprofen‐treated dogs the rate of bone loss was significantly decreased about both surgically and non‐surgically treated teeth throughout the 12‐month treatment period. This decreased rate was sustained through 3 months of the post‐treatment period, but was lost 6 months following the termination of flurbiprofen therapy. No similar effect on reducing the rate of bone loss was observed in the placebo‐treated dogs. A significant decrease in bone‐seeking radiopharmaceutical uptake was observed in the flurbiprofen‐treated teeth, which corresponded with the radiographic findings. Changes in gingival inflammation with flurbiprofen treatment were not observed. These data indicate that flurbiprofen is a potent inhibitor of alveolar bone loss in beagles and within 6 months of the termination of flurbiprofen the effect on slowing the rate of bone loss is lost.
Human complement activation by purified Capnocytophaga exopolysaccharide. Measurement by radioimmunoassay
Authors: Bolton R. W. , Dyer J. K.
Published: July 2006

Exopolysaccharide (EP) purified from spent culture fluid of three Capnocytophaga species was examined for its ability to activate the human complement system. Heparinized plasma was absorbed with bacterial cells to remove natural antibody. Aliquots of plasma were then incubated with EP for 1 h at 37 C and complement activation was evaluated by a radioimmunoassay specific for C3a (Upjohn Diagnostics). EP from each species of Capnocytophaga activated the complement system. The amount of C3a generated was dose‐dependent over a range from 1 to 1000 μg EP/ml plasma and reached a maximum of 28 μg C3a/ml plasma. Chelation of Ca++ with EGTA inhibited complement activation by EP, which suggested that activation occurred by the classical pathway.
Reproducibility of bleeding tendency measurements and the reproducibility of mouth bleeding scores for the individual patient
Authors: Janssen P. T. M. , Faber J. A. J. , van Palenstein Helderman W. H.
Published: July 2006

The aim of this study was to determine the accuray of bleeding tendency measurements in order to assess the probability values of differences in number of bleeding sites at successive examinations in the individual patient. Duplicate bleeding tendency measurements were performed in patients who had received initial treatment. Measurements in deep and shallow pockets showed different reproducibility values. The proportion of agreement on lack of bleeding was relatively high (86%) in shallow‐pockets (≤4 mm) and decreased significantly in deep pockets (> 4 mm). The proportion of agreement on bleeding was relatively low (36%) in shallow pockets and increased significantly in deep pockets. Chance distributions were calculated on basis of the reproducibility values of bleeding and non‐bleeding on probing. It was found that only large differences in the number of bleeding sites between two examinations can indicate a possible change in the periodontal condition of the individual patient. The sensitivity of the individual mouth bleeding score can be increased by recording as many sites as possible.
The influence of cigarette smoking on the development of experimental gingivitis
Authors: Bergström Jan , Preber Hans
Published: July 2006

The aim of this investigation was to study the influence of cigarette smoking on the development of gingivitis. Experimental gingivitis was induced in the mandibular anterior region by abstention from oral hygiene for 28 days. The study group consisted of 20 healthy dental students, 10 of whom were regular smokers. The clinical parameters studied were gingival bleeding on probing (60 g), gingival redness and gingival exudate. The results showed that the plaque formation rate was similar in both groups. However, smokers displayed a less pronounced gingival inflammatory reaction as compared with non‐smokers. Concerning gingival bleeding and gingival redness, the reaction in smokers was significantly less elevated from d 14 through d 28 and concerning the amount of gingival exudate it was significantly less elevated from d 21 through d 28. The differences between groups tended to increase with time. These results suggest that the inflammatory gingival response to accumulating plaque may be suppressed under the influence of cigarette smoking.
Effect of experimental periodontitis on fibroblast progenitor populations in hamster gingiva
Authors: McCulloch C.A.G.
Published: July 2006

The purpose of this study was to examine the effects of experimental periodontitis on the fibroblast progenitor populations of hamster gingiva. Two groups of 5 hamsters per group were examined after 60 d. The control group was fed laboratory chow, and the experimental group was fed Diet 2000 (Keyes & Jordan 1964). I h prior to killing all animals were injected with 3H‐thymidine. Plastic‐embedded sagittal sections through the first and second molar regions of the mandibles were prepared for enzyme histochemistry and radioautography. Experimental animals exhibited significantly higher numbers of osteoclast nuclei per mm of interdental bone than controls (p<.05) and significantly more bone loss as measured from the alveolar crest to the cementoenamel junction (p<.01). The number of alkaline phosphatase‐positive cells in apposition to the interdental bone surface and exhibiting osteoblast‐like morphology was similar in control and experimental animals. In the transseptal fiber zone, the number of cells per 1000 μm2 was not significantly different between control and experimental animals. The percentage of cells expressing non‐specific esterase activity and with the morphology of macrophages was significantly increased (p<.02) in the gingival connective tissue subjacent to thejunctional epithelium but not in the transseptal fiber zone of experimental animals. The percentage of cells labeled with 3H‐thymidine was significantly increased in the transseptal fiber zone (p<.02). The data suggest that, in spite of alveolar bone loss, the hamster maintains its connective tissue cell populations in zones superior to the alveolar crest. Maintenance of tissues homeostasis is achieved in part by increasing the size of the fibroblast progenitor pool.
In vitro study of crevicular fluid sampling methods: Sampling variability and effect of volume and orientation on fluid removed
Authors: Ralls Stephen A. , Cohen Mark E. , Junes Trevor R.
Published: July 2006

An in vitro system was designed to evaluate properties of gingival crevicular fluid (GCF) sampling. Four polysiloxane test wells were fabricated with volumes of 2.7. 4.3. 6.2 and 11.0 μl. Wells were sampled for a test solution of 50% fetal call serum in phosphate buffered saline, while in upright and inverted orientations, using capillary micropipettes and filter paper strips. With the pipette method. 6 sample volumes removed from each well were calculated directly. With the paper method, 1μ(Ci/ml of 3H‐lbymidine was added to the test solution, and countsper‐minute (CPM) were determined at 24 hours for 10 test samples in each condition and for 10 standard samples. For both sampling methods, well volume and well orientation had significant effects on amount of fluid removed. Larger volumes/increased CPM were obtained from both deeper and inverted wells. For upright wells only, a quadratic relationship, associated with a ceiling effect, was found between total well volume and volume removed/CPM. Coefficients of variation of measurements involving the paper method were higher than those for the pipette method when wells were inverted but not when they were upright. Pocket depth and tooth arch (analogs of variables tested in vitro) may affect GCF sampling variability in vivo.
Efficacy of supervised rinsing with chlorhexidine digluconate in comparison to phenolic and plant alkaloid compounds
Authors: Siegrist B. E. , Gusberti F. A. , Brecx M. C. , Weber H. P. , Lang N. P.
Published: July 2006

The experimental gingivitis model was used to compare the antigingivitis, antiplaque, and antimicrobial efficacies of two commercially available (a phenolic and a plant alkaloid) compounds used as mouthrinses with those of a mouthrinse containing chlorhexidine digluconate. Thirty‐one male and female volunteers with healthy gingivae and clean teeth ceased all oral hygiene procedures for 21 days during which they rinsed twice daily with: a) a phenolic compound (Listerine®), b) sanguinarine (Viadent®), c) 0.12% chlorhexidine digluconate, or d) a placebo mouthrinse. After 21 days of rinsing, virtually no signs of clinical gingivitis were observed in the chlorhexidine group. Subjects rinsing with Listerine, Viadent, or placebo developed clinical signs of gingivitis as measured by gingivitis occurrence, severity, and the proportion of gingival bleeding sites. At the same time, plaque accumulation was only slightly higher than at baseline in the chlorhexidine group, while the Listerine, Viadent, and placebo groups had significantly greater plaque accumulations, particularly during the initial period of treatment between day 0 and day 7. Microbiological enumeration of supragingival plaque collected at the end of the treatment period showed that chlorhexidine digluconate reduced plaque bacteria by 62–62% compared to the placebo group. No significant reductions in plaque bacteria were found among subjects using Listerine or Viadent.

This study demonstrated that 0.12% chlorhexidine digluconate was superior to Listerine and Viadent in its ability to maintain optimal gingival health during the entire three weeks of mouthrinse use. It was of particular interest to note these effects during the final 14 to 21‐day period of extreme challenge in this experimental model when gingivitis severity and bleeding site occurrence are most pronounced in the placebo group.
Blood flow in healed and inflamed periodontal tissues of dogs
Authors: Hock J. M. , Kim S.
Published: July 2006

The objectives of this study were to determine if increased blood flow associated with gingivitis would decrease following resolution of gingival inflammation in dogs with periodontitis; if increased blood flow in inflamed gingiva was associated with changes in the blood flow of alveolar bone, and if blood flow in gingiva and alveolar bone increased if periodontitis was reactivated by ligating teeth. Regional blood flow was measured in dogs with pre‐existing periodontitis, using radioisotope‐labelled, plastic microspheres. In the first experiment on 4 adult Beagle dogs, teeth in the left jaws were treated to resolve the periodontitis, while teeth in the right jaws were not treated. Gingival and bone blood flow were measured after 12 wk. Blood flow was significantly (p<0.05) lower in non‐inflamed healed gingiva (32.1±2.7 ml/min/100 g) than in inflamed gingiva (46.1±5.3 ml/min/100 g). No differences in the blood flow of alveolar bone underlying inflamed or non‐inflamed gingiva were present. In the second experiment, the right mandibular teeth of 5 dogs were treated to resolve periodontitis while teeth in the other quadrants were ligated for 4, 10 or 12 wk. The duration of ligation did not alter blood flow. Gingival blood flow around ligated maxillary and mandibular teeth was comparable and approximately 54% higher than around non‐ligated teeth (p±0.03). The difference in blood flow between gingiva with G.I. ± 1 and gingiva with G.I.±2 was significant (p±0.04). Blood flow in bone was not altered by changes in the inflammatory status of the overlying gingiva. The findings suggest that changes in blood flow associated with inflammation are reversible and that blood flow in alveolar bone is regulated independently of gingival blood flow.
Human periodontal ligament cells in vitro
Authors: Rose George G. , Yamasaki Akira , Pinero Gerald J. , Mahan Charles J.
Published: July 2006

This paper reports on ultrastructural features of human periodontal ligament (PDL) cells growing in vitro as primary outgrowths and as continuous lines. The two most striking features of these cells were: 1) their branching bands of micro filaments containing semiperiodic dense nodes; and 2) the massive amounts of glycogen (α and β particles) found in many cells. Both of these features, particularly the glycogen, were found in an earlier study of the human PDL in vivo. In that study, of 22 teeth, glycogen was located universally in the cementoblasts and superjacent fibroblasts but not in the PDL fibroblasts more distant from the cementum.
Progesterone metabolism by rat oral mucosa. III. Participation of granulation tissue and fibroblasts
Authors: Ojanotko‐Harri Anita , Hurttia Helena , Harri Matti‐Pekka
Published: July 2006

The metabolism of progesterone by rat granulation tissue was studied. Experimental granulation tissue was produced by implanting viscose‐cellulose sponges beneath the dorsal skin of female and male rats for 21 days. The granuloma capsules and fibroblasts in the sponges were homogenized, and mitochondrial, microsomal and soluble fractions were prepared with differential centrifugation. The subcellular Preparations were incubated with 4‐14C‐progesterone and NADPH for 30 min at PH 7.4 and 37°C. The metabolites were identified with column and multiple thinlayer chromatography and radioautography and quantitated with liquid scintillation counting. The granulation tissue and fibroblasts showed much less activity in metabolizing progesterone than the gingival tissue of either sex. As reported earlier, gingival tissues contain Δ4‐5α‐ and,Δ4‐5β‐steroid hydrogenases and 3α‐, 3β‐, 20α‐ and 20β‐hydroxysteroid dehydrogenases. The granulation tissue and fibroblasts lack 3 β‐hydroxysteroid dehydrogenase activity. In addition, the fibroblasts show no 20 β‐hydroxysteroid dehydrogenase activity. The enhanced metabolism of progesterone during gingival inflammation is thus probably not due to the formation of granulation tissue.
Quantitation and optimization of enzymatic and mechanical procedures to produce high‐yield single cell suspensions from human gingiva
Authors: McCulloch C. A. G. , Knowles G. , Overall C. M.
Published: July 2006

Existing enzymatic and mechanical techniques of cell release from human gingiva were quantitated in regard to: cell yield; viability; freedom from cell clumping; and debris formation. To optimize these parameters methodologies were modified and combined with new procedures which included incubation with a variety of enzymes. Fibrous and inflamed tissues from 17 patients were examined. The optimal procedure that was selected included thorough mincing of the tissue plus the addition of DNA‐ase, elastase and hyaluronidase to a standard bacterial collagenase mixture. Consistently, up to 3.4 × 106 cells per 100 mg of tissue were released after tissue digestion, with a mean viability of 85%. The cell suspensions were relatively free of debris and cell clumps. Data from Coulter particle counting was in close agreement with hemocytometer counts. The composition of the cell suspension was not significantly different from the original tissue sample. Tissue remnants following the digestion procedure only contained an estimated 1 % of the original number of cells in the sample. The single cell suspensions produced using this method were found to be suitable for analysis by flow cytometry. The possible selective cytotoxicity of the enzymatic technique on cell populations in the DNA‐synthesis phase of the cell cycle was examined in healthy gingival tissue of a Cynomolgus monkey. The gingiva was injected with 3H‐thymidine and the percentage of labeled fibroblasts was enumerated in radioautographs either of sections prepared from undigested tissue or in smears of single cell suspensions. There was no significant difference in the percentage of labeled cells between sections or smears. The data suggest that the method reported here can be applied to flow cytometry analysis of progenitor cell populations in gingival tissues.
Immunoelectron microscopic studies on the distributions of fibronectin and actin in a cellular dense connective tissue: the periodontal ligament of the rat
Authors: Pitaru S. , Aubin J. E. , Bhargava U. , Melcher A. H.
Published: July 2006

Mouse monoclonal anti‐fibronectin antibodies and rabbit affinity‐purified actin antibodies were used with gold‐labelled secondary antibodies to study the distributions of fibronectin and actin within the periodontal tissues of the rat. Following perfusion fixation, demineralization, and embedding in glycolmethacrylate, sections 70–80 nm thick were obtained from the gingiva, periodontal ligament and the supporting bone of the first and second mandibular molars. In both gingiva and periodontal ligament, fibronectin was located over the collagen fibers and at certain sites at the cell‐collagen interface. In addition, unbanded fibrillar material 10–20 nm thick was decorated by fibronectin antibodies. Actin was localized primarily in the peripheral cytoplasm and at the cell‐extracellular matrix interface. Labelling for actin was detected at a few sites within the extracellular matrix. In double labelling experiments, fibronectin and actin were observed to co‐distribute at cell‐matrix interfaces. These data support the concept that fibronectin within the dense connective tissue of the rat gingiva and periodontal ligament, as in other soft connective tissues, may mediate the interaction between different components of the extracellular matrix and between these components and the cell membrane. In addition, they strengthen the hypothesis that actin filaments may be active in vivo in the formation of cell‐matrix contacts, and that actin and fibronectin may form fibronexus‐like structures similar to those described for fibroblasts in culture.
Protein production by human gingival fibroblasts is enhanced by guanidine EDTA extracts of cementum
Authors: Somerman M. J. , Archer S. Y. , Shteyer A. , Foster Ft. A.
Published: July 2006

Nonconfluent cultures of human gingival fibroblasts were exposed to both guanidine and guanidine EDTA extracts of cementum for 48 hours. To compare the effects of cementum extracts on fibroblasts with other mineralized tissue extracts, cells were also exposed to guanidine and guanidine EDTA extracts of dentin and alveolar bone. The cells were radioactively labeled during the last 24 h. Total protein production was measured via the incorporation of radioactive proline. Collagen production was estimated by digestion of the radioactive protein mixture with bacterial collagenase. All guanidine EDTA extracts elicited statistically significant increases in total protein production compared to controls. At 50 μg/ml of extract, the increases in protein production were 340%, 143% and 338% for bone, cementum and dentin, respectively. Similar results were obtained for collagen production. In contrast, the guanidine extracts had no effect on either protein or collagen production by human gingival fibroblasts. These data indicate that the functions of gingival fibroblasts can be altered by proteins from associated mineralized tissues. Identifying such proteins and understanding their biological functions will enhance our knowledge of the mechanisms that regulate connective tissue regeneration.
Demonstration of tissue collagenase activity in vivo and its relationship to inflammation severity in human gingiva
Authors: Overall Christopher M. , Wiebkin Ole W. , Thonard John C.
Published: July 2006

To directly demonstrate both the presence and in vivo activity of tissue collagenase (EC 3.4.24.7) during gingival inflammation, tissue extracts from 54 specimens of variously inflamed human gingiva were analyzed individually for: a) collagenase‐specific collagen degradation products, and b) collagen‐bound collagenase. The TCA collagen degradation product, identified using SDS‐PAGE, was shown in 13/19 (68.4%) of insoluble tissue‐residue fractions extracted from moderate‐to‐severely inflamed gingiva, but in only 2/21 (9.6%) slight‐to‐mildly inflamed gingival specimens, suggesting differences in the in vivo collagenase activity between the two groups. Using in vitro collagenase assays, gingival collagenase (as bound to insoluble collagen) was demonstrated in 92.8% of the moderate‐to‐severely inflamed gingival specimens and in 50% of the slight‐to‐mildly inflamed gingival specimens. A relationship was established between the active and latent forms of the enzyme and the degree of inflammation. Active enzyme was present in 78% of the moderate‐to‐severely inflamed specimens and in 14% of the slight‐to‐mildly inflamed gingiva. In contrast, latent collagenase was predominant in the slight‐to‐mildly inflamed group (86% of coliagenase‐positive samples) compared with 46% of coliagenase‐positive moderate‐to‐severely inflamed gingival samples. The collagen‐bound gingival collagenase was inhibited by metal ion chelators, sulphydryl reagents and 10% FBS, but not by serine nor thiol‐proteinase inhibitors and is therefore a neutral metalloproteinase.
Solubilized dental plaque is mitogenic for nylon wool‐purified human cord blood T lymphocytes
Authors: Baker John J. , Tondreau S. P.
Published: July 2006

Human cord blood T lymphocytes were purified by filtration through nylon wool columns and tested for their ability to synthesize DNA in response to stimulation with solubilized dental plaque, phytohemagglutinin and streptolysin O. Ninety out of 106 cord blood T lymphocyte preparations (85%) responded significantly (p≤0.05) to solubilized dental plaque. DNA synthesis was maximal after 7 days of culture; 20 μg of solubilized dental plaque was the optimal dose. A similar frequency of significant responses (89%) was obtained with the T lymphocyte mitogen, phytohemagglutinin; however, streptolysin O, an antigen, stimulated only 23% of the T lympyhocyte preparations significantly. The high frequency of significant cord blood T lymphocyte responses to solubilized dental plaque was not affected by maternal periodontal status, nor could any evidence be found for the removal of adherent suppressor cells by the nylon wool purification. Furthermore, cord blood leukocyte and mononuclear cell cultures responded about as frequently as, and synthesized more total DNA than T lymphocyte cultures to solubilized dental plaque. Freshly prepared solubilized dental plaque was shown to contain inhibitors as well as activators of lymphocyte transformation, and was significantly less immunogenic (mitogenic) than an older, frozen preparation of solubilized dental plaque. These results indicate that solubilized dental plaque contains one or more mitogens for human T lymphocytes.
Local Shwartzman activity of lipopolysaccharides from several selected strains of suspected periodontopathic bacteria
Authors: Koga Toshihiko , Odaka Chikako , Moro Itaru , Fujiwara Taku , Nishihara Tatsuji , Okahashi Nobuo , Hamada Shigeyuki
Published: July 2006

Lipopolysaccharides (LPSs) were isolated fromFusobacteriumspecies,Bacteroidesspecies,Actinobacillus actinomycetemcomitansandEscherichia coliby the phenol water procedure, and their capacity to induce the local Shwartzman reaction was determined. Preparatory and provoking injections of homologous LPS preparations caused LPSs fromE. coliandF. nucleatumto induce a hemorrhagic necrosis, indicating a typical Shwartzman reaction. On the other hand, LPSs fromA. actinomycetemcomitansandB. gingivalisinduced a weak inflammatory lesion, but no necrotic lesion. The provoking activities of LPSs fromF. nucleatumandA. actinomycetemcomitansin inducing an inflammatory lesion were comparable to that of LPS fromE. coli, but the activity of LPS fromB. gingivaliswas low. The preparatory activities of LPSs fromB. gingivalisandB. oralisin inducing an inflammatory lesion were comparable to those of LPSs fromF. nucleatum, F. necrophorumandA. actinomycetemcomitans.
Methodological aspects and quantitative adjuncts to computerized subtraction radiography
Authors: McHenry K. , Hausmann E. , Wikesjö U. , Dunford R. , Lyon‐Bottenfield E. , Christersson L.
Published: July 2006

The methodology for the use of subtraction radiography in the study of human periodontal disease is described in detail to include: 1) design and fabrication of a system for taking standardized radiographs; 2) generation of interpretable subtraction images; 3) adjunctive, quantitative methods for analyses of digitized radiographic images; 4) reference standard for periodontally healthy individuals. Correct use of our system for taking standardized radiographs can provide a sufficient number of pairs of radiographs for the study of patients with severe periodontitis using subtraction radiography. Changes in bone mass observed on subtraction images can be quantified by measurement of their areas and their relationship to the alveolar crest.
Tissue pressure in rat oral mucosa measured by micropuncture technique
Authors: Johannessen Anne Christine , Fjærtoft Marie , Heyeraas Karin J.
Published: July 2006

Tissue pressure or interstitial fluid pressure (IFP) was measured in 68 rats in different areas of the oral mucosa (free gingiva, attached gingiva in front and molars, alveolar mucosa, hard palate, cheek) by glass pipettes (diameter 2‐4 μm) connected to a servocontrolled counterpressure system. All the measurements of IFP were considerably above ambient pressure. The highest IFP was measured in the hard palate (14.8 mm Hg) and in attached gingiva (8.6, 9.2 mm Hg), while free gingiva, alveolar mucosa and cheek showed lower values (2.3, 3.6, 1.5 mm Hg respectively). Venous stasis resulted in an immediate rise in IFP in the attached gingiva. Repeated measurements of IFP at the same location gave the same results 3 h after induction of anesthesia, and there was no change in IFP in continuous recordings for up to 30 min. Administration of indomethacin did not change IFP. The results show that IFP in oral mucosa is high and that there is a marked regional variation in IFP, which may reflect regional differences in aspects of anatomy and function. The great difference between IFP in attached and free gingiva shows that there is a pressure gradient between these tissues, possibly maintained by the anatomical structure and the drainage of gingival fluid into the gingival sulcus.
The effect of chlorhexidine on blood cells
Authors: Gabler Walter L. , Roberts Daniel , Harold William
Published: July 2006

Chlorhexidine was cytotoxic to both neutrophils and red blood cells over a narrow concentration range of 0.01 to 0.02% drug. Serum provided significant protection against the cytotoxic effects of the antimicrobial agent. At a concentration of 0.01%, chlorhexidine acted as a potent activator of the neutrophil's oxidative burst, stimulating the cells to produce oxygen radicals such as super‐oxide (O−2). Chlorhexidine ranging from 10−4 to 10−2 caused spontaneous degranulation of neutrophils. If neutrophils were pretreated with chlorhexidine and then activated by the chemoattractant tripeptide FMLP, chlorhexidine inhibited the induced Of generation and degranulation. If, on the other hand, neutrophils were activated with phorbol myristate acetate (PMA) following chlorhexidine treatment, the antimicrobial agent enhanced both O−2 synthesis and degranulation. It appears that the responsiveness of chlorhexidinetreated neutrophils to subsequent activators is dependent upon the nature of the activator.
Effect of spiramycin therapy on human periodontal disease
Authors: Sznajder N. , Piovano S. , Bernat M. I. , Flores L. , Macchi R. , Carraro J. J.
Published: July 2006

The aim of this study was to evaluate the effect of spiramycin on subgingival microflora and periodontal tissues in 10 patients, divided into 2 groups of 5 patients each, with 14 sites studied in each group. The 28 sites were examined at baseline, immediately before drug or placebo intake and then 2 and 4 weeks later. The assessment included oral hygiene status, gingival conditions, bleeding on probing, crevicular fluid and morphotype count by darkfield microscopy. On a double blind basis, patients received, at random, placebo (control group) or spiramycin (test group) 3 g the first day and 2 g daily during a fortnight. In the test group, results at 2 wk examination showed a statistically significant increase (p<0.05) in coccoid cells, and reduction of motile rods and spirochetes, as well as pocket depth decrease. Plaque Index, Gingival Index and Crevicular Fluid only changed at 4 wk examination. No changes were recorded for the control group. The above improvements were maintained up to 15 d following drug administration. The authors suggest that spiramycin could be used profitably as an adjunct to mechanical therapy in reducing the periodontopathic flora.
Qualitative and quantitative studies of Gc (vitamin D‐binding protein) in normal subjects and patients with periodontal disease
Authors: Krayer Joe W. , Emerson David L. , Goldschmidt‐Clermont Pascal J. , Nel Andre E. , Werner Philip A. , Galbraith Robert M.
Published: July 2006

Qualitative and quantitative studies of Gc (Vitamin D‐binding protein) were carried out with whole and parotid saliva from 13 patients with periodontal disease, and 19 control subjects. Using an ELISA technique, a low concentration of Gc was found in the parotid saliva of all subjects. The whole saliva of patients with periodontal disease contained concentrations of Gc which were significantly increased over those in either dentulous or edentulous control subjects (p<0.01). In addition, the Gingival Index scores of these patients correlated with the concentration of Gc (r = 0.87; p<0.01). Rocket immunoelectrophoresis showed that > 90% of Gc in saliva from these patients was complexed with G‐actin.
Human gingival fibroblasts secrete non‐dialyzable, prostanoid‐independent products which stimulate bone resorption in vitro
Authors: Lerner Ulf , Hänström Lennart
Published: July 2006

Conditioned media from human gingival fibroblasts stimulate release of radioactive calcium, stable calcium and inorganic phosphate from mouse calvarial bones in organ culture. In addition, human gingival fibroblast‐conditioned media decrease the hydroxyproline content in the bones. Stimulation of mineral mobilization could be reduced by calcitonin, bisphosphonates and glucocorticoids, but not by cyclooxygenase inhibitors. The production of stimulating factors by fibroblasts was unaffected by indomethacin, meclofenamic acid and naproxen. Dialysis of human gingival fibroblast‐conditioned media showed that the product(s) had a molecular weight larger than 3000 daltons. Bone resorbing activity in human fibroblast‐conditioned media was heat‐labile. These data show that human gingival fibroblasts can secrete non‐prostanoid products with the ability to stimulate osteoclastic bone resorption in vitro.
Collagenolytic activity of black‐pigmented Bacteroides species
Authors: Sundqvist G. , Carlsson J. , Hänström L.
Published: July 2006

Strains of black‐pigmented Bacteroides were examined for their ability to degrade collagen, albumin and benzoyl‐D‐L‐arginine‐p‐nitranilide (BAPNA). B. gingivalis was the only species that showed activity against collagen and BAPNA. This activity was cell‐bound, stabilized by dithiothreitol and inhibited by sulphy‐dryl‐modifying reagents such as mercuric, cupric and zinc ions, 5.5′‐dithiobis‐2‐nitrobenzoic acid, p‐chloromercuriphenylsulfonic acid and hydrogen peroxide. The activity was also inhibited by the chelating agents EDTA and EGTA. This indicated that B. gingivalis has cell‐bound thiol proteinase activity dependent on metal ions.
The effects of phenytoin (5, 5‐diphenylhydantoin) on human gingival fibroblasts in culture
Authors: Vernillo Anthony T. , Schwartz Nancy B.
Published: July 2006

Macromolecular biosynthesis in monolayer cultures of normal and responder human gingival fibroblasts derived from tissue explants was evaluated in the presence or absence of phenytoin (5μg/ml) from the 5th to the 8th day after plating and a labeling period with 14C‐proline (0.2 μCi/ml) for the last 48 hours. Collagenase digestion and hydroxyproline determinations indicated an increase in collagen product. At least part of the increase may have been due to a drug‐modulated decrease in collagen degradation. Phenytoin (PHT) also stimulated synthesis of glycosaminoglycan as indicated by an approximately 2‐fold increase in sulfate‐labeled product. Ultrastructural examination revealed a pronounced change in the protein synthetic apparatus of PHT‐treated cells. Tritiated phenytoin bound to fibroblasts and appeared to undergo internalization as indicated by trypsin treatment.
Immunocytochemical localization of extracellular matrix components in beagle periodontium: I. Collagen types I and III in healthy gingival connective tissue
Authors: Cho Moon‐II , Lee Yu Lin , Garant Philias R.
Published: July 2006

The localization and identification of types I and III collagen in healthy gingival connective tissue of the beagle dog were investigated using indirect immunofluore‐scent and immunoferritin electron microscopic techniques with affinity purified antibody or IgG. Type I collagen was evenly distributed throughout the lamina propria and the underlying connective tissue in the form of thick collagen fibers. In the lamina propria, these fibers appeared to run from the underlying connective tissue in a perpendicular orientation to the overlying gingival epithelium. Localization of type III collagen was restricted to the lamina propria and the connective tissue around blood vessels. Immunoferritin electron microscopy clearly revealed that type I collagen fibrils have a diameter ranging from 40 to 100 nm and a clear 640 Å cross‐banding pattern. Thin and short collagen fibrils, 18 to 32 nm in diameter, were labelled with antitype III collagen IgG. A 640 Å cross‐banding pattern was rarely observed in these fibrils. Type III collagen fibrils coexisted with type I collagen fibrils in a mixed pattern within the lamina propria and the perivascular space.
Regeneration of the connective tissue attachment on surgically exposed roots using a fibrin‐fibronectin adhesive system. An experimental study on the baboon (Papio ursinus)
Authors: Ripamonti U. , Petit J. ‐C. , Lemmer J. , Austin J. C.
Published: July 2006

To evaluate the regeneration of the connective tissue attachment promoted by a fibrin‐fibronectin adhesive system, the buccal, interradicular and interproximal alveolar bone to one half of the length of the roots was removed from the maxillary molars and premolars of 2 chacma baboons. The exposed roots were planed and demineralized with citric acid. On flap closure a fibrin‐fibronectin adhesive system (Tisseel®) was introduced between the root surfaces and the mucoperiosteal flaps in the experimental quadrants. To avoid immunological reactions, Tisseel prepared from baboon plasma was used. Histometrical analysis was performed on a total of 13 experimental and 12 control specimens obtained 95 d post‐operatively. The analysis of variance demonstrated significant differences between the experimental and control specimens with regard to the length of connective tissue attachment or adaptation (p = 0.0234), the extent of newly formed cementum with inserted connective tissue fibers (p = 0.0033) and the amount of bone regeneration (p=0.0068). This limited study indicates that the potential for connective tissue attachment and bone regeneration may be enhanced by the use of specific attachment glycoproteins and plasma factors.
Wolinella recta, Campylobacter concisus, Bacteroides gracilis, and Eikeneila corrodens from periodontal lesions
Authors: Tanner A. C. R. , Dzink J. L. , Ebersole J. L. , Socransky S. S.
Published: July 2006

The fastidious gram negative asaccharolytic rods Wolinella recta, Campylobacter concisus, Bacteroides gracilis, and Eikeneila corrodens have been isolated from lesions of advanced periodontal disease. In this investigation, three methods were compared for their ability to identify fresh isolates of these species: 1) biochemical tests and sensitivities to dyes and other inhibitors, 2) serological reactions, and 3) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). SDS‐PAGE of total cell proteins appeared to be the most sensitive and accurate method to identify isolates, although many strains were successfully identified using serology. Biochemical tests including sensitivities to inhibitors were the least reliable. W. recta, B. gracilis, and E. corrodens were found more frequently and in higher numbers in progressive (active) disease sites of many of the subjects. E. corrodens was also found to be significantly elevated in inactive sites of certain subjects. After successful treatment with Widman flap surgery and systemically administered tetracycline, the proportions of W. recta and E. corrodens were reduced, while those of C. concisus were elevated.
Collagen membranes prevent the apical migration of epithelium during periodontal wound healing
Authors: Pitaru S. , Tal H. , Soldinger M. , Azar‐Avidan Orna , Noff M.
Published: July 2006

Collagen membranes were interposed between full thickness periodontal flaps and denuded root surfaces of right upper canines in 3 mongrel dogs; the left canines were sham‐operated without the use of collagen membranes. Animals were killed 10 d after surgery. Tissue blocks were removed, and experimental and control sites were processed for histometric and histologic examination. The results indicate that collagen membranes: (i) prevent apical migration of the epithelium during initial stages of healing; and (ii) are colonized by connective tissue cells and incorporated within the healing connective tissue.
Microbiology of periodontal disease
Authors: Moore W. E. C.
Published: July 2006

There is a perception of conflicting data and opinions among research laboratories that are studying periodontal microbiology. In response to this perception I was asked to discuss recent literature in this field at the 1986 Annual Meeting of the American Association of Dental Research. This review is based on that discussion which primarily concerned all of the relevant papers that were available to me and that had been published in the last 2 years (1984 and 1985). In order to determine what the data (rather than what our biases) may tell us, accurate comparisons of published reports in this field require an appreciation of the reasons for different results in different laboratories. Therefore, before we compare data, let's consider some of the reasons why results from different laboratories may differ. The periodontal flora is complex. We have found over 325 distinct bacterial species in the human gingival crevice (1). Many of these species have never been formally described, most of them are ignored by some laboratories, identified differently by others, or lumped together in various groups by still others. Some of the predominant species have special growth requirements and are not detected on some media that are widely used. Identification criteria differ among laboratories. Even with rigorous testing, identification of some species is questionable. With minimal testing it is even less reliable.
Human periodontal ligament in vitro: Cell culture passage effect on collagen gel contraction
Authors: Murphy Kevin G. , Daniel Jon C.
Published: July 2006

Fibroblasts seeded within a lattice of a Type I collagen gel will exert tension on collagen fibrils and eventually contract the gel, forming a three‐dimensional network. Using adult human tissue, the ability of PDL fibroblasts (HPDL) and human gingival fibroblasts (HGF) to contract collagen gels was compared. All cells were grown in monolayer and cell passage was performed as confluency was reached. Gel diameter was measured for a 10‐d period after seeding the cells in the matrix. At d 1 through 10, the HGF contracted the gel to a greater extent than the HPDL. HPDL did not contract at a significantly different rate than fibroblasts derived from human sclera or human foreskin. When early passage HPDL and HGF were compared, the early passage HPDL cells contracted gels at a significantly reduced rate. The early passage HPDL cells demonstrated a large population of cells that did not display a normal extension of pseudopodia. However, the late passage HPDL gels contained a majority of cells displaying a normal cellular process extension, suggesting a heterogeneity of the cell population. This data supports the hypothesis that the cell culture monolayer environment may alter the functional characteristics of the HPDL, possibly by selecting against a subpopulation of cells which is present in primary culture and in vivo.