bluuebunny/crossref_metadata_2025 huggingface dataset:
Levels of phosphate buffered saline‐ and citrate buffer‐elutable immunoglobulins in healthy and inflamed gingiva of dogs
Authors: Yamashita Satoshi , Hara Kohji , Nohara Hiroyoshi
Published: July 2006

The amounts of phosphate buffered saline (PBS)‐elutable IgG, IgA, and IgM and citrate buffere‐elutable IgG derived from insoluble immune complexes in healthy and inflamed gingiva of dogs were determined. To obtain healthy gingiva, the dogs' teeth were brushed for 6 wk. After achieving clinically healthy gingiva, plaque formation was induced by placement of silk floss ligatures in the cervical area of teeth and inflamed gingiva was obtained after 1 wk and 1 and 3 months of plaque accumulation. The PBS‐elutable IgG was measured by single radial immunodiffusion, IgA and IgM by electroimmunoassay, and citrate buffer‐elutable IgG by enzyme‐linked immunosorbent assay. The PBS‐elutable IgG and IgM in inflamed gingiva showed a tendency to increase with the progress of the disease. Particularly, the amount of IgG after 3 months of plaque formation increased to 183.2 μg/100 μg DNA and was significantly higher than that of the healthy gingiva, 88.2 μg/100 μg DNA (p < 0.05). The IgM value was highest 1 wk after plaque accumulation. On the other hand, the amount of citrate buffere‐lutable IgG in inflamed gingiva was significantly higher than that in healthy gingiva at all experimental periods (p < 0.05) and the increase showed a close parallel with the progression of inflammation.
The adherence of Eikenella corrodens to guinea pig macrophages in the absence and presence of anti‐bacterial antibodies
Authors: Miki Y. , Ebisu S. , Okada H.
Published: July 2006

The interaction of oral bacteria with host cells may play an important role in the pathogenesis of periodontal disease. The purpose of this study was to investigate the adherence mechanism of Eikenella corrodens 1073 to guinea pig peritoneal macrophages in the absence or presence of anti‐bacterial antibodies. The first experiments were focused on the mechanism of E. corrodens adherence to macrophages in the absence of antibodies and complements. The adherence was dependent on time, bacterial concentration and pH. The adherence was inhibited by ethylendiaminetetraacetic acid and restored by adding calcium ions. Heating (100°C for 5 min) or protease (trypsin or pronase) treatment of bacterial cells abolished their capacity to adhere to macrophages. The specificity of E. corrodens adherence to macrophages was also proved using a hapten inhibition assay with saccharides. Among the sugars tested, the adherence was sensitive to N‐acetyl‐D‐galactosamine (GalNAc)‐ and D‐galactose (Gal)‐containing sugars. GalNAc was the most potent inhibitor, being 10 times greater than Gal. These results suggest that the adherence of E. corrodens to macrophages in the absence of antibodies and complements may require the interaction between bacterial cell surface lectins and GalNAc‐like receptors on the surface of macrophages. The second group of experiments was aimed at comparing the adherence mechanism of anti‐body‐nontreated E. corrodens to macrophages with that of antibody‐treated E. corrodens. The adherence of antibody‐treated E. corrodens reached a plateau after incubation for 10 min, whereas that of antibody‐nontreated E. corrodens reached a plateau after incubation for 30 min. The adherence of antibody‐nontreated E. corrodens was completly inhibited by GalNAc, whereas the adherence of antibody‐treated E. corrodens was only slightly inhibited by GalNAc. Treatment of macrophages with heat aggregated IgG before incubation with antibody‐treated E. corrodens caused an 80% decrease in adherence. These results show that E. corrodens adherence to GalNAc‐like receptors on the macrophage surface via bacterial lectin in the absence of antibodies is quite different from the mechanism of E. corrodens adherence to Fc receptors in the presence of bacterial antibodies.
Root resorption caused by mechanical injury of the periodontal soft tissues in rats
Authors: Nakane Satoshi , Kameyama Yoichiro
Published: July 2006

The purpose of the present investigation was to study, histologically, the effect on the root surface of mechanical injury to the periodontal soft tissues in rats. The animals were subjected to mechanical injury with a flat, needle‐like instrument only in the gingiva and the cervical periodontal ligament of the first maxillary molar. Odontoclastic root resorption occurred in part of the root surface at the alveolar crest level at 1 day. It extended gradually in the coronal direction over the following days, reaching part of the root surface at the cementoenamel junction at 14 d, and undermining part of the dentin below the enamel just above the cementoenamel junction at 21 d. The result of the present study indicated that mechanical injuries of human gingival soft tissues being sustained accidentally or during dental treatments might cause odontoclastic resorption of the root surface.
Indomethacin or flurbiprofen treatment of periodontitis in beagles: Comparison of effect on bone loss
Authors: Williams R. C. , Jeffcoat M. K. , Howell T. H. , Hall C. M. , Johnson H. G. , Wechter W. J. , Goldhaber P.
Published: July 2006

The effect of two non‐steroidal anti‐inflammatory drugs, indomethacin and flurbiprofen, on the progression of periodontal disease was studied in 16 beagle dogs over a 12‐month period. Standardized radiographs were used to measure the rate of bone loss. Following a 6‐month pretreatment baseline period, 5 dogs were dosed daily with 1.0 mg/kg indomethacin, 5 dogs were dosed daily with 0.02 mg/kg flurbiprofen, and 6 dogs were dosed with empty gelatin capsules for a 6‐month period. In the untreated control dogs, the rate of bone loss in the treatment period significantly increased from baseline. In contrast, the rate of bone loss significantly decreased from baseline in the flurbiprofen‐treated dogs. In the indomethacin‐treated dogs, rate of bone loss in the treatment period was not significantly different from baseline. The data indicate that both flurbiprofen and indomethacin inhibit alveolar bone loss in beagles compared to untreated controls. The data also indicate that with the dosages employed flurbiprofen is overall more effective.
Axial periodicity in periodontal collagens. Human periodontal ligament and gingival connective tissue collagen fibers possess a dermis‐like D‐period
Authors: Gathercole L. J. , Porter S. , Scully C.
Published: July 2006

The use of synchrotron X‐ray diffraction has enabled us to record for the first time the first few orders of the collagen meridional low angle pattern from small, weakly diffracting native specimens of human periodontal ligament and gingival connective tissue, and to measure the D‐period (fibrillar axis molecular overlap plus hole repeat) accurately. Comparison with human and other mammalian tendon and dermal specimens indicates that the D‐period in both periodontal tissues resembles the value for dermal collagen, 65 nm, rather than that for tendon collagen, 67 nm.
Epithelial cell rests of Malassez bind epidermal growth factor intensely
Authors: Thesleff Irma
Published: July 2006

The binding of 125I‐labelled epidermal growth factor (EGF) in the dental follicle was studied by autoradiography. The follicle of a surgically removed impacted premolar was cut into small pieces which were incubated in the presence of 125I‐EGF. Very intense binding was localized in the epithelial cell rests of Malassez, whereas only background labelling was seen in fibroblastic cells. EGF is a hormone‐like molecule which is believed to exert its effects locally and through binding to a specific cell surface receptor. The number of EGF receptors in many cells – e.g., basal epidermal cells ‐ is related to cell proliferation. The present observations indicate that EGF receptors are expressed in high amounts by the cells of the epithelial rests, and that these cells are thus potentially responsive to the actions of EGF. It can be speculated that activation of the epithelial rest cells in various pathologic conditions is associated with a local rise in the tissue level of EGF.
Periodontal treatment requirements of recently incarcerated prison inmates
Authors: Barnes G. P. , Parker W. A. , Fultz R. P. , Rees T. D. , Lyon T. C.
Published: July 2006

The purpose of this study was to determine the needs for preventive dentistry counselling, prophylaxis and calculus removal and periodontal therapy among recently incarcerated state prison inmates. As a result of clinical and radiographic examinations of 637 male inmates, these requirements were determined for the total sample and for four age groups, three ethnic groups, six crime‐type groups, three residency groups, five intelligence quotient groups and first offenders and recidivists. Among the total sample, 93% of the men needed preventive counselling, prophylaxes and calculus removal; 32% required Type I and/or Type II periodontal treatment. Young men required less periodontal therapy than older inmates. Caucasians needed fewer segments of treatment than Hispanics. Sex offenders required less prophylaxes and calculus removal than men convicted of burglary, larceny and drug‐related crimes. Treatment requirements were not related to residency, recidivism or intelligence quotient. The findings indicate extensive requirements for periodontal and adjunctive therapy among incarcerated men and should influence resource allocation in prison dental care delivery systems.
Serum antibodies to Bacteroides ginglvalis in periodontitis: A longitudinal study
Authors: Mouton C. , Desclauriers M. , Allard H. , Bouchard M.
Published: July 2006

The level of systemic antibodies to B. gingivalis was assessed longitudinally in a group of 11 adult patients with chronic periodontitis and in 9 periodontally healthy subjects. Immunoglobulin G (IgG), IgA and IgM‐specific antibodies were measured by an enzyme‐linked immunosorbent assay in serum samples obtained during the natural course of the disease and following scaling and root planing. A serological dichotomy was observed throughout the study in the chronic periodontitis patients. A first subgroup was characterized by a virtual absence of IgA antibody and by IgG and IgM levels similar to those of healthy individuals, suggesting a low level of colonization by B. gingivalis. The patients of the second subgroup had detectable IgA and a significantly higher IgG antibody level that probably reflected the presence of a B. gingivalis infection. There was no statistical difference between the two subgroups for Plaque Index, Gingival Index, probeable pocket depth and age. No cyclic pattern of the antibody levels was observed over the monitoring interval. No peak level of antibody was observed in the immediate posttreatment period, suggesting that scaling and root planing may not provoke active immunization with B. gingivalis. Antibody titres reduced by half 1 year following scaling and root planing were observed in patients presumably infected with B. gingivalis, suggesting that the procedure effectively reduced the immune challenge.
The influence of chlorhexidine on superoxide generation by induced human neutrophils
Authors: Gabler W. L. , Bullock W. W. , Creamer H. R.
Published: July 2006

Chlorhexidine directly stimulates the generation of superoxide anion (O2) by neutrophils at nontoxic concentrations of the drug (less than 0.01%). The kinetics of drug‐induced O2 generation simulated that of receptor‐mediated FMLP induction of O2, but not that of PMA‐induced synthesis. Nontoxic concentrations of chlorhexidine inhibited FMLP‐induced generation of O2 if the neutrophils were pretreated with chlorhexidine or if chlorhexidine and FMLP were added simultaneously. Cells activated first by FMLP were unaffected by chlorhexidine. These data support the concept that chlorhexidine interferes with the binding of FMLP to its receptor. Chlorhexidine inhibited both the velocity and the duration of FMLP‐induced O2 synthesis. In contrast, chlorhexidine promoted PMA‐induced O2 generation irrespective of the sequence of addition of chlorhexidine and PMA. Chlorhexidine decreased the lag interval between PMA induction and O2 synthesis, and increased the velocity of synthesis, which leads us to propose that chlorhexidine increases PMA penetrance of neutrophils. Since neither nonionic detergents nor polycationic polymers separately minic the effect of chlorhexidine treatment, it appears that more than surfactant or charge effects are involved. The interrelation between the positive charge and the hydrophobic domain of chlorhexidine plays a role in the drug‐neutrophil interaction which directly stimulates O2 generation, and which modulates neutrophil responsiveness to FMLP and to PMA.
Blood group substances as differentiation markers in human dento‐gingival epithelium
Authors: Steffensen B. , Lopatin D. E. , Caffesse R. G. , Hanks C. T.
Published: July 2006

The level of cellular differentiation of human oral, sulcular, and junctional epithelium was compared by immunohistochemical analysis of cell membrane‐associated blood group‐specific carbohydrates. Identification of the blood group A‐specific carbohydrate and its two immediate precursor substances, type 2 chain H and N‐acetyllactosamine, was accomplished by an indirect immunofluorescence technique. Murine monoclonal antibodies reacting specifically with the antigenic determinants of the blood group substances were used as markers. The blood group A substance, indicating the highest level of cellular differentiation, was demonstrated on the cells in the upper layers of the oral epithelium. In the sulcular epithelium, the A substance was present on a few cells only, while type 2 chain H was observed frequently. This indicates an intermediate differentiation level of sulcular epithelium. The type 2 chain H precursor, N‐acetyllactosamine, the indicator of the lowest level of cell differentiation among the tested substances, was the only blood group substance detected on the junctional epithelial cells and on the basal cells of the sulcular and oral epithelium. Based upon previous studies of cell renewal and differentiation in oral epithelium, the present results indicate that the variations in distribution of the different blood group substances correspond with the regional rates of cell division and the levels of cellular differentiation. The findings also suggest that the cells in the junctional epithelium differentiate to a level similar to that of basal cells in the oral epithelium.
Suppression of lymphocyte and fibroblast proliferation by Actinomyces viscosus‐activated murine macrophages
Authors: Metzger Z. , Hoffeld J. T. , Charon J. , Mergenhagen S. E.
Published: July 2006

Actinomyces viscosus, a normal inhabitant of the oral cavity, has previously been shown to evoke immune responses in the host. Macrophage activation by this microorganism was studied in a murine system. Peritoneal macrophages, activated in vivo by A. viscosus had a suppressive effect on lymphocyte proliferation in vitro; total suppression occurred at a PEC to lymphocyte ratio of 6:10. A. viscosus‐activated macrophages also suppressed the proliferation of normal syngeneic fibroblasts, with a 96% suppression at a PEC to fibroblast ratio of 9:1. Resident peritoneal macrophages had no suppressive effect on either target cell population. Suppression of fibroblast proliferation by A. viscosus‐activated macrophages was partially reversed by catalase (20000 U/ml) or indomethacin (10‐5M), suggesting involvement of hydrogen peroxide and cylo‐oxygenase product(s). A. viscosus‐activated macrophages produced, upon stimulation, large amounts of H2O2 (256 nmole per mg protein, in 120 min) which were comparable to those produced by C. parvum‐activated macrophages. Resident peritoneal macrophages produced only minor quantities of H2O2 under the same conditions. The suppressive effects observed suggest that A. viscosus, by activating macrophages, may modulate the host's immune response and may hamper the repair potential of chronically inflamed connective tissue by inhibition of fibroblast proliferation. Other constitutents of the plaque may share this effect.
Effects of flurbiprofen on the progression of periodontitis in Macaca mulatta
Authors: Offenbacher S. , Braswell L. D. , Loos A. S. , Johnson H. G. , Hall C. M. , McClure H. , Orkln J. L. , Strobert E. A. , Green M. D. , Odle B. M.
Published: July 2006

The effect of the nonsteroidal anti‐inflammatory drug flurbiprofen has been studied in the ligature‐induced and spontaneous periodontitis model in the rhesus monkey, Macaca mulatta. Twenty‐four adult monkeys with incipient periodontitis were divided into three disease‐matched groups. Two groups received flurbiprofen at dosages of either 0.27 mg/kg/d or 7.1 mg/kg/d delivered systemically via osmotic minipump. A split‐mouth approach was used, placing ligatures on one side and monitoring the progression of periodontitis at regular intervals for 6 months. Clinical measurements included standardized radiographs, Ramfjord attachment level determinations and assessments of redness, edema and bleeding on probing. There was a statistically significant inhibition of attachment loss (p < 0.05), gingival redness (p < 0.05) and bleeding on probing (p < 0.05) in ligatureinduced and spontaneous periodontitis in the flurbiprofen‐treated animals at 6 months. Eight of 8 ligated control monkeys lost significant attachment (mean loss of 1.06 mm/site). Only 3 of 15 flurbiprofen‐treated ligated monkeys lost any significant attachment, with an overall mean loss of 0.34 mm/site, which was significantly less than the control loss of 1.06 mm/site at p = 4.46 times 10‐3. The odds of a control ligated monkey undergoing significant attachment loss in 6 months are elevated 29.3‐fold, as compared to the flurbiprofen‐treated, cohort monkey group. Flurbiprofen treatment also significantly inhibited spontaneous attachment loss for 6 months as compared to control monkeys, at p < 0.05. These data provide further evidence for the central role of cyclooxygenase products in the progression of periodontal disease. The ability of flurbiprofen to inhibit periodontal attachment loss, even in the presence of gross plaque accumulation, has significant implications for the potential use of flurbiprofen as an adjunctive periodontal therapeutic modality.
Isolation and characterization of protease from culture supernatant of Bacteroides gingivalis
Authors: Otsuka M. , Endo J. , Hinode D. , Nagata A. , Maehara R. , Sato M. , Nakamura R.
Published: July 2006

Caseinolytic protease was isolated and purified, with high yield, from culture supernatant of Bacteroides gingivalis 381 by procedures including acetone fractionation, gel filtration on Sepharose CL‐6B, solubilization with 0.8% 1‐O‐N‐octyl‐β‐D‐glucopyranoside and affinity chromatography on arginine‐Sepharose 4B. By the affinity chromatography, the protease was separated into three isoenzymes, one of which was unadsorbed on the arginine‐Sepharose 4B, but the other two of which were adsorbed and eluted with the buffer at a different concentration of arginine. Caseinolytic activities of the latter two were highly dependent on dithiothreitol and were inhibited by both thiol‐blocking reagents and some microbial protease inhibitors; but such inhibition was not found in the former isoenzyme. The higher the affinity of the enzyme to arginine‐Sepharose, the stronger the thiol dependency and the inhibition by these inhibitors. Phosphoramidone and ethylenediamine tetraacetate had no effect on the activity of any of the three peaks, indicating that the enzyme is not a metaloprotease. Besides the enzymehydrolyzed synthetic substrates of trypsin, such as BApNA, TAME, substrates of chymotrypsin and kallikrein were also hydrolyzed. The salivary and egg‐white lysozymes were also degraded by this enzyme. These findings suggest that the protease produced by B. gingivalis may play a role as a periodontopathogen not only in directly destroying periodontal tissues but also in weakening the oral antibacterial mechanism.
Effect of ultrasonic instrumentation on dental plaque microflora in vitro
Authors: Thllo B. E. , Baehni P. C.
Published: July 2006

The aim of the present study was to investigate in vitro the effects of an ultrasonic scaler on the composition of dental plaque and selected bacterial isolates. Plaque samples obtained from patients with periodontitis were submitted for 10 s, 20 s, 30 s and 60 s to ultrasonication. Bacterial suspensions were then examined by dark field microscopy and cultured on solid medium to evaluate bacterial growth. Dark field microscopic counts showed that percentages of spirochetes and motile rods decreased sharply after 10 s of sonication and could no longer be detected after 60 s. Conversely, a relative increase in the percentage of coccoid cells as well as others was observed. Cultures of plaque samples following ultrasonication demonstrated a marked increase in CFU between 0 and 10 s to reach a maximum at 30 s. When bacterial suspensions containing Treponema vincentii LA‐1 and Streptococcus mutans OMZ 176 were submitted to ultrasonication, a net decline in the percentage of spirochetes and a concomitant increase in cocci were observed by dark field. After 30 s there were exclusively cocci in the suspensions and spirochetes were virtually undetectable. The effect of ultrasonication on spirochetes viability was also evaluated using pure cultures of T. vincentii LA‐1 and T. denticola CD‐1. The data indicated that 10 s or 30 s of sonication had an adverse effect on both species because no growth could be observed in these cultures. It can be concluded that vibrations generated by an ultrasonic scaler have the potential to alter the composition of dental plaque and to kill spirochetes in vitro.
Injection of an antigen into the gingiva and its effect on an experimentally induced inflammation in the knee joint of the mouse
Authors: Lens Jan Willem , Beertsen Wouler
Published: July 2006

Antigen was injected into the gingiva and tested for its ability to induce a flare of a chronic arthritis. Joint inflammation was established by a local injection of 100 μg methylated bovine serum albumin (mBSA) in the right knee joint of immune mice. About 4 wk later, 0·5‐1 mg mBSA was injected into the gingiva. It was found that this antigenic challenge induced a flare of the arthritis as measured with the 99mTechnetium (99mmTc) uptake method. Light microscopic examination of the knee joints revealed an increase of inflammatory cells in the synovial tissue and the joint space. The results indicate that, under certain experimental conditions, antigenic material administered to the gingiva can influence an inflammation elsewhere in the body.
Endotoxin‐stimulated mononuclear phagocytes secrete soluble factors with boneresorbing activity
Authors: Gregory Stephen H.
Published: July 2006

An in vitro co‐culture system composed of bone marrow‐derived mononuclear phagocytes (obtained from endotoxin‐responsive mice) and 45Ca‐labeled calvaria (obtained from endotoxin‐hyporesponsive mice) was established in order to examine the direct effect of bacterial endotoxin on bone resorption mediated by mononuclear phagocytes. Co‐cultures treated with endotoxin exhibited a significant increase in bone resorption assessed in terms of the %45Ca released. This increase was observed in the absence of direct contact between the mononuclear phagocyte population and bone, indicating that enhanced resorption occurred as a function of soluble factors secreted by mononuclear phagocytes in response to endotoxin. Co‐cultures which contained devitalized 45Ca‐calvaria failed to exhibit an increase in the %45Ca released following endotoxin treatment. Consequently, the soluble factors secreted by endotoxin‐stimulated mononuclear phagocytes appeared to modulate the activity of endogenous bone‐resorbing cells. Two soluble factors with bone‐resorbing activity were distinguished upon subsequent analysis. These results suggest that the interaction between plaque‐associated bacterial endotoxin and mononuclear phagocytes may have important consequences relevant to the resorption of alveolar bone characteristic of chronic periodontal disease.
Glycosaminoglycans of human cementum
Authors: Bartold P. Mark , Miki Yasuo , McAllister Bred , Narayanan A. Sampath , Page Roy G.
Published: July 2006

The glycosaminoglycans in human cementum have been studied. Following proteolytic digestion of guanidine/EDTA and collagenase extracts of cementum, glycosaminoglycans were isolated and then separated by cellulose acetate membrane electrophoresis. After specific elimination by enzymatic and chemical treatments the glycosaminoglycans were identified as hyaluronic acid, chondroitin sulfate and dermatan sulfate. Neither heparan sulfate nor keratan sulfate were observed. Quantitation of the glycosaminoglycans in both extracts revealed chondroitin sulfate to represent the major species present. Hyaluronic acid was observed predominantly in the guanidine/EDTA extract while dermatan sulfate was a quantitative minor component of both extracts.
Serological classification of Bacteroides from the human oral cavity
Authors: Ebersole J. L. , Taubman M. A. , Smith D. J. , Frey Deirdre E.
Published: July 2006

Studies were initiated to investigate the antigenic relationship among oral species of Bacteroides. Antigenic differences among the Bacteroides were assessed with an ELISA using antisera from immunized rabbits and sera obtained from subjects with periodontal disease. Multiple species of Bacteroides were examined, including: B. gingivalis, 2 homology groups of B. intermedius, B. melaninogenicus, B. denticola, B. loescheii, B. oralis, B. levii, B. gracilis, B. buccae. and B. corporis. Both rabbit and human sera reacted with distinct surface antigenic determinants in each of the species of Bacteroides. Additional relationships were defined, such that the 2 homology groups of B. intermedius exhibited a similarity of approximately 30–40%, while the B. melaninogenicus and B. loescheii showed a 20–25% similarity of surface antigens. B. denticola was antigenically related to the B. intermedius and B. melaninogenicus strains by 10–15%. The remaining cross‐reactivities were generally less than 5% among the Bacteroides species. The findings are consistent with specific surface antigenic determinants on the oral Bacteroides spp. and suggest the ability to detect specific responses to these organisms in periodontal disease patients.
Do collagen fibrils of the periodontal ligament shrink with age?
Authors: Luder Hans U. , Zimmerli Irene , Schroeder Hubert E.
Published: July 2006

Do collagen fibrils of the periodontal ligament shrink with age? Certainly not! Based on the quantitative estimation of over 25000 periodontal ligament collagen fibrils at 3 periodontal levels of 28 freshly extracted human teeth, using 10‐ to 75year‐old subjects and high resolution electron micrographs evaluated planimetrically, the present study demonstrates with data obtained from 2 sampling procedures that the diameter of the average collagen fibril, i.e., 54 to 59 nm, is rather constant throughout the human life span. This is particularly true for the vast majority of comparatively large fibrils (i.e., 57 to 64 nm), while a numerically limited population of small fibrils (i.e., 40 to 48 nm) in fact increased in diameter with age. These results are discussed in view of analogous data for other connective tissues and of the functional and metabolic status of such tissues.
Cemento‐enamel junction–revisited
Authors: Schroeder Hubert E. , Scherle Walter F.
Published: July 2006

The cemento‐enamel junction (CEJ) of human teeth has been studied very infrequently and on the basis of ground sections only. A total of 30 human teeth (incisors, premolars, molars) was prepared for examination with the scanning electron microscope (SEM). A selection of freshly erupted first premolars (n=8) and third molars (n=8) served for a quantitative determination of the entire, as well as the site‐specific (buccal, distal, oral and mesial aspects), length of the CEJ and of the respective extension of the 3 hard tissue relationships along the CEJ. In addition, 4 third molars were used to examine the CEJ in ground sections, using both the light‐ and the scanning electron microscope. In first premolars, most of the CEJ revealed edge‐to‐edge contact of cementum and enamel, while in 17 (maxillary premolars) to 31% (mandibular premolars) of the CEJ cementum overlapped the enamel. In third molars, cementum overlap occurred in about 50% of the CEJ, the rest showing either edge‐to‐edge contact of cementum and enamel or exposed dentine. In molars, the type and extension of these relationships changed from buccal‐to‐distal to oral‐to‐mesial aspects. Because of an unpredictable variation in these relationships over short distances, examination of ground sections may fail to correctly identify the CEJ‐structure.
Ultrastructural study of experimental cementum regeneration in rats
Authors: Knox B. , Aukhil I.
Published: July 2006

The present study examined two phases of experimental cementum regeneration at the ultrastructural level. Small fenestration wounds (1 mm in diameter) were made on the mesial root of mandibular first molars in 20 Lewis strain rats to remove cementum and periodontal ligament. The wounds were covered with sheets of Nucleopre filter, before replacing the extraorat flaps, to allow population of denuded roots by cells arising mainly from the adjacent periodontal ligament. The rats were sacrificed in two batches of 10 each to provide observation periods of 2 and 4 weeks. The specimens were processed for transmission electron microscopy. At 2 wk, fibroblasts exhibiting ultrastructural features suggestive of various stages of synthetic activity were seen in the wound and adjacent to denuded root surfaces which appeared irregular. At 4 wk, cementoid regeneration was seen with bundles of oriented collagen fibrils inserting into the cementoid matrix. A consistent finding at both observation periods was the presence of an electron‐dense, granular zone between the cementum/collagen matrix and the denuded root surface. Contrary to previous reports, the electron‐dense zone appeared bi‐layered with collagen fibrils and filamentous material in the superficial layer. At both observation periods, synthetic activity and matrix organization were more advanced in areas away from the root surface (fibrillogenesis) compared to areas adjacent to the root surface (cementogenesis). The present findings suggest that some important cellular and molecular events, possibly regulatory in nature, occur during the early stages of cementum regeneration in rats.
Possible transmittance of A. actinomycetemcomitans from a dog to a child with rapidly destructive periodontitis
Authors: Preus Hans R. , Olsen Ingar
Published: July 2006

This study was designed to detect a possible exogenous source of oral A. actinomycetemcomitans in a family where the 2 children suffered from Papillon‐Lefévre syndrome (PLS). Every month for 1 yr subgingival dental plaque samples were obtained from the 2 children, their parents, grandparents and their pet dog. Dental plaque samples were also obtained from a 12‐yr‐old boy whose family had owned a dog from the same litter as the PLS family. Dispersed and diluted plaque samples were cultured anaerobically on Slots medium and A. actinomycetemcomitans was identified by standard criteria. The various A. actinomycetemcomitans wild strains were mass cultivated and their total genomes compared after DNA restriction endonuclease mapping in 2 different electrophoretic gels, using ECO RI, HIND III and BAM HI. Only the plaque samples from 1 of the PLS children, the pet dog and the 12‐yr‐old boy produced A. actinomycetemcomitans. The restriction endonucleases could not distinguish between the A. actinomycetemcomitans wild strains from the PLS child and those from the family dog or the 12‐yr‐old boy. However, the methods could readily differentiate between both reference strains and wild strains, indicating that transfer of A. actinomycetemcomitans from dog to the PLS child had taken place.
Control of gingival hemorrhage in hemophilic patients by inhibition of fibrinolysis with tranexamic acid
Authors: Sindet‐Pedersen Steen , Stenbjerg Stainer , Ingerslev Jøgen
Published: July 2006

The aim of the present investigation was to evaluate the effect of mouthrinsing with tranexamic acid on the demand for replacement therapy in hemophilic patients demonstrating spontaneous gingival bleeding or bleeding following subgingival scaling. The study included one retrospectively studied group (I) of hemophilic patients treated with oral antifibrinolytics, replacement therapy and local hemostatics, and a prospectively studied group (II) in whom no replacement therapy but systemic and/or local antifibrinolytic treatment with tranexamic acid was employed. Six of the patients in group T received replacement therapy to control bleeding, while none of the patients in group II experienced bleeding episodes demanding replacement therapy. The difference in the frequency of demand for replacement therapy between the two groups was statistically significant (p<0.02). Based on the present findings, it is advocated that treatment of gingival bleeding in hemophilic patients should include local antifibrinolytic treatment.
Stimulation of bone resorption in cultured mouse calvaria by met‐lys‐bradykinin
Authors: Ljunbbren Östen , Lerner Ulf H.
Published: July 2006

Met‐lys‐bradykinin, which may be released from kininogen due to cleavage by neutrophil leukocyte acid proteases, stimulated 45Ca release from prelabelled mouse calvarial bones. The stimulatory effect of met‐Iys‐bradykinin on 45Ca release was inhibited by indomethacin, meclofenamic acid, flurbiprofert, and calcitonin. Met‐lys‐bradykinin caused a dose‐dependent stimulation of prostaglandin E2 production in osteoblast‐enriched mouse calvarial bone cells. These findings indicate that increased biosynthesis of prostaglandins, capable of stimulating osteoclast‐mediated bone resorption, may be implicated in the mechanism by which metlys‐bradykinin stimulates bone resorption. Our observations suggest that, in addition to bradykinin and lys‐bradykinin, met‐lys‐bradykinin may be a potential mediator of bone resorption in inflammatory lesions.
Culture and characterization of rat junctional epithelium
Authors: Altman Leonard C. , Nelson Caron L. , Povolny Brian , Fleckman Philip , Dale Beverly A. , Maier Ronald V. , Soderland Carl , Baker Coralle
Published: July 2006

Junctional epithelium, which forms the interface between the gingival tissues and the teeth, is a unique nondifferentiating, nonkeratinizing simple epithelium with essentially no gradient of cytoplasmic alterations. The purpose of this study was to develop methods for obtaining and culturing junctional epithelial cells and characterizing these cells with monoclonal antibodies and by keratin analysis. Microsurgical methods were developed to obtain pure specimens of junctional epithelium from the interproximal molar regions of pathogen‐free rats. Specimens of palatal and free gingival epithelia were also taken. The tissue explants were cultured by three methods; an explant technique using 3T3 fibroblasts as feeder cells, a procedure which used cloning rings to isolate primary epithelial outgrowths, and growth in small chambers coated with solubilized basement membrane. Specimens from the three oral epithelia grew well by all methods and appeared homogenous by phase contrast microscopy. Immunocytochemical analysis of fresh specimens by antikeratin antibody staining showed differences in the staining patterns of the three oral epithelia and suggested the absence of 54 and 40 kD keratins from these tissues. Junctional, palatal and gingival epithelial cells grown by the cloning ring technique stained positively with the monoclonal antibody 34βE12 which stains all stratified epithelia and identifies 66 and 57 kD keratins, but failed to stain with antibodies to vimentin and desmin which are intermediate filament proteins in mesenchymal and muscle cells, respectively, Junctional epithelial cells grown on solubilized basement membrane showed positive staining with antidesmoplakin antibodies I and II, which identify desmosomal plaque proteins, and negative staining with the keratin‐specific monoclonal antibody AE2. Gingival cells grown by the same technique had the opposite staining pattern with these antibodies. Cells grown by the 3T3 feeder cell method were analyzed for their cytokeratin content by SDS polyacrylamide gel electrophoresis and immunoblotting using the keratin‐specific monoclonal antibodies AEl and AE3. The keratin patterns in freshly explanted tissues all differed, indicating that these oral epithelia are indeed different in vivo. Further, the keratin patterns in extracts of subconfluent and confluent cultured oral epithelial cells differed from those in the freshly isolated tissues, but were similar for the different epithelia. Specifically, subconfluent cultures of the three epithelia had identical keratin patterns, but differed from those of confluent cultures which were themselves identical. This report presents methods for obtaining and culturing junctional epithelium, and data which indicate that junctional cells differ from other oral epithelia in cytokeratin and desmosomal protein composition.
Investigation of the distribution of cementum‐associated lipopolysaccharides in periodontal disease by scanning electron microscope immunohistochemistry
Authors: Hughes F. J. , Auger D. W. , Smales F. C.
Published: July 2006

Previous work in our laboratory has suggested that cementum‐associated LPS is confined to the surface of affected roots. In order to localize the distribution of cementum‐associated LPS more precisely, an immunogold/silver labelling system has been utilized to demonstrate LPS on scanning electron microscope images of scaled, extracted teeth. With this technique, antibody binding to the specimen is detected by electron probe X‐ray microanalysis of the bound silver label. Most of the detectable LPS was found to be associated with bacteria and calculus which persisted on the root surface despite the scaling of the specimens. Smaller amounts of bound LPS were also detected on the cuticle and surface cementum layers of the affected root surfaces, but in places where some of the underlying cementum had been removed no LPS was detected. These results cast some doubt on the importance of the removal of cementum‐bound endotoxins in the treatment of periodontal disease. From these results it is postulated that the principal therapeutic effect of extensive cementum removal by root planing is that it facilitates the removal of plaque and calculus from resorption lacunae, which were a prominent feature of the affected root surfaces.
Regulation of collagen production in fibroblasts cultured from normal and phenytoin‐induced hyperplastic human gingiva
Authors: Narayanan A. S. , Meyers D. F. , Page R. C.
Published: July 2006

We have studied how collagen production is regulated in fibroblasts obtained from normal and phenytoin‐induced hyperplastic human gingiva. Collagen production was determined as collagenase digestible radioactivity and degradation was examined by adding labelled procollagen to the cultures and by pulselabelling in the presence of lysosomal inhibitors. Collagen mRNA levels were measured using a [35S]‐UTP labelled proα[1] probe. The normal and phenytoininduced fibroblasts did not degrade collagen extracellularly and lysosomal inhibitors did not enhance collagen production in either culture. Collagen production by the cultures correlated with mRNA levels, and in 2 of 3 phenytoin‐induced fibroblasts, which produced more collagen than other cells. collagen mRNA levels were higher. We conclude that collagen production in gingival fibroblasts is primarily regulated by the mRNA levels and that overproduction of collagen by cells from phenytoin‐induced hyperplastic gingiva results from an increased steady state level of collagen mRNA and not decreased collagen degradation.
Re‐epithelialization of a palatal connective tissue graft transplanted in a non‐keratinized alveolar mucosa: A histological and biochemical study in humans
Authors: Ouhayoun J. P. , Sawaf M. H. , Goffaux J. C. , Etienne D. , Forest N.
Published: July 2006

This study was undertaken to evaluate the type of tissue obtained after transplantation of a connective tissue graft, from the same palatal donor site, into a non‐keratinized oral mucosa in humans. In 6 human volunteers, a thick palatal epithelio‐connective tissue graft was excised, split into two thinner grafts (a thin epithelio‐connective tissue graft and a connective tissue graft) and transplanted into controlateral areas lacking keratinized gingiva. The biopsies, excised 3 months post‐operatively, were examined using routine histology, immunofluore‐scence techniques with different anticy to keratin antibodies and biochemical techniques with non‐equilibrium two‐dimensional gel electrophoresis. The results show that the epithelio‐connective tissue grafts display the histological and biochemical characteristics of keratinized gingiva, whereas the connective tissue grafts expressed features belonging both to keratinized and non‐keratinized gingival tissues. It is concluded that the deep palatal connective tissue does not have the full potential to induce non‐keratinized epithelial cells to keratinize and that a gingival or palatal connective tissue graft without its overlying epithelium is not likely to yield genuine attached gingiva.
Indomethacin or flurbiprofen treatment of periodontitis in beagles: Effect on crevicular fluid arachidonic acid metabolites compared with effect on alveolar bone loss
Authors: Williams R. C. , Offenbacher S. , Jeftcoat M. K. , Howell T. H. , Johnson H. G. , Hall C. M. , Wechter W. J. , Gotdhaber P.
Published: July 2006

The effect of two non‐steroidal anti‐inflammatory drugs, indomethacin and flurbiprofen, on the progression of alveolar bone loss and on the crevicular fluid (CF) levels of four arachidonic acid metabolites was compared in 16 beagle dogs over a 12‐month period. Standardized radiographs were used to measure the rate of bone loss. Radioimmunoassay was used to measure CF levels of PGE2, PGF2α, TxB2 and 6K‐PGF1α. Following a 6‐month pretreatment baseline period, 5 dogs were dosed daily with 1.0 mg/kg indomethacin, 5 dogs were dosed daily with 0.02 mg/kg flurbiprofen, and 6 dogs were dosed with empty gelatin capsules for a 6‐month period. With the administration of either indomethacin or flurbiprofen. the CF levels of PGE2, PGF2α, and TxB2 were similarly significantly decreased; 6K‐PGF1α levels were not altered. Indomethacin and flurbiprofen did not have a similar effect on reducing the rate of alveolar bone loss. Flurbiprofen significantly decreased rate of bone loss from baseline whereas indomethacin did not. The data indicate that indomethacin and flurbiprofen inhibit CF arachidonic acid metabolite levels in a similar manner, but not rate of bone loss. The data suggest that flurbiprofen's striking effect on inhibiting rate of bone loss cannot be solely attributed to simple cyclooxygenase inhibition with a reduction in CF prostaglandin levels.
The effect of interleukin‐1 β on hyaluronic acid synthesized by adult human gingival fibroblasts in vitro
Authors: Bartold P. Mark
Published: July 2006

The effect of recombinant interleukin‐1β (IL‐lβ) on hyaluronic acid synthesis by human gingival fibroblasts was studied. IL‐1bT caused a dose‐dependent increase in the incorporation of (3lucosamine into hyaluronic acid. The 35S/35H ratios of labeled macromolecules did not change regardless of the presence or absence of TL‐lβ and indicates stimulation of hyaluronic acid synthesis. Inhibition of cell proliferation by hydroxyurea caused an increase in hyaluronic acid synthesis. The effect of IL‐1β on hyaluronic acid synthesis in the presence of hydroxyurea was increased over untreated and IL‐lβ‐treated controls, but equivalent to the hydroxyurea‐treated controls. Thus the effect of IL‐1β on hyaluronic acid synthesis may be independent of cell proliferation. Furthermore, inhibition of prostaglandin E2 synthesis by indomethacin abolished the effect of IL‐1β on hyaluronic acid synthesis. Inhibition of new protein synthesis by cycloheximide negated the effect of IL‐β on hyaluronic acid synthesis. This may be related to inhibition of new hyaluronate synthetase synthesis, since IL‐1β stimulated the level of hyaluronate synthetase activity. Sepharose CL‐2B chromatography revealed that most of the newly synthesized hyaluronic acid was of large molecular size. The cells exposed to IL‐1β retained more large molecular size hyaluronic acid in their cell layer environment than did the control cells. These responses by fibroblasts to IL‐1β may be indicative of early tissue repair.
Variance components analysis of data from periodontal research
Authors: Sterne J. A. C. , Johnson N. W. , Wilton J. M. A. , Joyston‐Bechal S. , Smales F. C.
Published: July 2006

Although periodontal disease status and progression may vary at different sites in the same subject, statistical models of data from periodontal research must not assume independence of different observations made on the same subject. Methods to analyze appropriate statistical models for data from periodontal research exist, but have hitherto required the data set to be generally balanced. Algorithms for the estimation of ‘variance components’ or ‘multilevel’ models for the analysis of unbalanced data which possess a nested structure have, however, recently been developed. The use of a simple variance components model is illustrated using data from a periodontal clinical trial. The conclusions reached differed from those reached by the original analysis, which did not take account of within‐subject differences. Such models may be generalized, for instance to allow for random effects or longitudinal data. These models will be useful in the study of the etiology and pathogenesis of periodontal diseases.
Effects of minocycline on fibroblast attachment and spreading
Authors: Somermen M. J. , Foster R. A. , Vorsteg G. M. , Progebin K. , Wynn R. L.
Published: July 2006

One of the initial events required for periodontal regeneration is the attachment and subsequent spreading of fibroblasts at the healing site (root surface). In order to further our understanding of the possible role of tetracyclines in connective tissue attachment, human gingival fibroblasts exposed to minocycline and tetracycline were evaluated for cell attachment and spreading properties in vitro. The results indicated that both minocycline and tetracycline enhanced cell attachment, but minocycline had greater efficacy. Enhanced cell attachment to polystyrene uncoated dishes was seen at a 20 μg/ml dose of minocycline, while maximum cell attachment was seen at 50 μg/ml. Exposure of cells to 200 μg/ml of minocycline resulted in a decline from maximum cell attachment. In addition, cell spreading was inhibited at the higher concentrations of drug. Cells exposed to 50 μg/ml of minocycline for 2 days had no change in total protein or collagen production when compared to control cells. This dose of minocycline had no effect on cell proliferation at 2 d, but over a 7‐d time course there was a significant decline in cell proliferation. These findings are important to clinical assessment of tetracyclines and indicate that such evaluations should include establishment of doses that favor cell attachment and spreading.