bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on saliva in ODU plaque‐susceptible rats having experimental gingivitis
Authors: Ohura K. , Shinohara M. , Mori M. , Takai N. , Yoshida Y. , Kakudo Y.
Published: July 2006

Saliva was collected from the submandibular, parotid, and sublingual glands at to compare the amount of saliva between ODU plaque‐susceptible (Sus) and plaque‐resistant (Res) rats. The amount of saliva secreted was less in the Sus rats than in the Res rats. This difference was mainly due to a decrease in salivation from the submandibular glands, which resulted from the decrease in the weight of these glands. This reduction in salivation may be associated with the rapid rate of plaque formation seen around the mandibular teeth of these animals and the development of periodontal diseases.
A new 51Chromium assay for accurate measurement of cell attachment to demineralized and non‐demineralized dentine in vitro
Authors: Lowenberg B.F. , Aubin J.E. , Pitaru S. , Melcher A.H.
Published: July 2006

Fibroblast‐like cells (RGF) derived from rat gingival explants were labelled with radioactive chromium (51Cr) and plated into Linbro 96‐well microtitre plates, each well of which contained one 200 μm‐thick slice of root. The root slices were removed at various times, washed, and counted in a gamma scintillation counter to determine the number of attached cells. The results obtained were expressed as counts per unit area of root, which could be converted to cell number per unit area. A linear correlation was established between the number of cells plated and the number of cells that attached in the range 0.6 to 10 × 104 cells per well. Visual corroboration of this relationship was provided by examination of root slices using scanning electron microscopy.

A significant proportion of cells was found by this assay not to be removed from the slices of tooth using standard trypsinization procedures. In the case of demineralized tissue, more cells remained adherent to the root slices than were removed. Consequently, trypsinization and counting procedures as they are normally employed no longer provide an acceptable assay for cell attachment to root surfaces.

Cell attachment to root slices demineralized for 1/2 h at 37°C with ethylenediaminetetraacetic acid (EDTA) was compared with attachment to untreated roots. It was found that there was no significant difference in the number of cells attaching to undemineralized compared to demineralized roots over a 4 h period. Consequently, greater rates of migration and division as well as chemotaxis, rather than attachment, may account for the improved healing obtained with demineralized root surfaces as compared to undemineralized surfaces in experimental wounds of the periodontium.
Periodontal disease in the domestic cat
Authors: Reichart P.A. , Dürr U.‐M. , Triadan H. , Vickendey G.
Published: July 2006

One hundred and fifty teeth from 15 cats of an average age of 6.8 years were examined macroscopically, radiographically, and histologically. Clinical inspection revealed plaque and calculus deposits on the facial surfaces of maxillary and mandibular premolars and molars. Radiography showed horizontal and vertical loss of alveolar bone with irregular defects of the dental hard structures. Histologically, typical features of gingival and periodontal destruction were found and resorptive lacunae were seen at the cemento‐enamel junctions. In comparison with experimentally induced periodontitis in other animals, periodontal disease involving external root resorption seemed to occur spontaneously in the cat.
Cell surface glycoconjugates of gingival fibroblasts exposed to dental plaque extract
Authors: Larjava Hannu , Jalkanen Markku
Published: July 2006

The cell surface glycoconjugates of human gingival fibroblasts exposed in a culture to dental plaque extract were studied by surface labeling techniques and indirect immunoflurescennce. After 24 h of exposure, the fibroblast morphology changed from well‐spread to spindle‐like. This alteration was associated with a disappearance of the intercellular fibronectin (FN) network and most of the high molecular weight cell surface glycoproteins. These effects of the extract were prevented by heating. After prolonged treatment with the native extract, a 80 kd glycoprotein disappeared and a 140 kd glycoprotein was replaced by a 110 kd polypeptide, but the trypsin sensitive 55 kd glycoprotein remained on the surface of the treated cells. The protcolytic activity of the plaque extract degraded the FN to various fragments with a different molecular weight than previously obtained with several purified mammalian enzymes. After a 24 h incubation of the treated cells in a normal, serum supplemented medium, the normal surface characteristics and FN network were recovered. In the treated cells, the phosphorylation of the cell surface glycoproteins was increased as well as the activity of the hyaluronic acid synthetase. The results suggest that plaque extract has a dual role in affecting the behavior of gingival fibroblasts. First, the enzymatic degradation of the FN network and surface glycoproteins destroys the association between the extracellular matrix and the cytoskeleton. Second, heat‐stable components alter the cell surface phosphorylation. These changes are associated with an activation of the cells to produce hyaluronic acid, the most striking anabolic change obtained in treated cells.
Proteoglycan production by chick embryonic chondrocytes is inhibited by culture filtrate of Bacteroides gingivalis
Authors: van Kampen G. P. J. , van Steenbergen T. J. M. , Schipper C. A. , de Graaff J. , Veldhuijzen J. P.
Published: July 2006

Culture filtrate of Bacteroides gingivalis was tested in vitro for its effect on the proteoglycan synthesis (35S‐sulfate incorporation) of chick embryonic chondrocytes. The chondrocytes were cultured in high density aggregates. The culture medium (M 199 with 10% fetal calf serum) was supplemented with 20% culture filtrate, 20% heat inactivated culture filtrate (100°C, 10 min), or 20% of a low molecular fraction (M < 1000) of the culture filtrate. Control aggregates were cultured with 20% bacterial medium added to the culture medium. Exposure of chondrocytes to culture filtrate resulted in a rapid reduction of the synthesis of proteoglycans within 5 hours. After 24 hours of culture proteoglycan synthesis was decreased by 80%. The small amount of proteoglycans still synthesized was mainly deposited into the medium whereas in control aggregates most proteoglycans were deposited around the cells. Protein synthesis was not changed and DNA synthesis was slightly increased by the culture filtrate. When after 24 hours of culture the medium with culture filtrate was replaced by control medium, this resulted in a rapid and total repair of the proteoglycan synthesis. The effect of culture filtrate on the proteoglycan synthesis did not change after heat inactivation or using the low molecular fraction, indicating that small, non‐proteinous molecules are responsible for the described effects.
Microtubules in periodontal ligament cells in relation to tooth eruption and collagen degradation
Authors: Beertsen W. , Everts V. , Hoeben K. , Niehof A.
Published: July 2006

The effects of the anti‐microlubular drug colchicine on the eruption of the continuously growing mouse incisor and the structure of its periodontal ligament, which is thought to be responsible for generating the eruptive force were studied. It was observed that both the eruptive process and the microtubular apparatus in the cells of the ligament are affected by the drug in a dose‐dependent fashion, thereby lending support to the view that eruption is related to the functioning of microtubules in periodontal ligament cells. Since colchicine did not seem to interfere with collagen degradation. as measured in terms of collagen phagocytosis by fibroblasts and loss of connective tissue attachment in the supra‐alveolar region, the inhibition of eruption is not likely to be due to an increased resistance force in the periodontal ligament as a result of decreased collagen breakdown.
The significance of alveolar bone in periodontal disease
Authors: Nyman Sture , Ericsson Ingvar , Runstad Lilian , Karring Thorkild
Published: July 2006

The present experiment was designed to study if a gingival unit with a long supraalveolar connective tissue attachment provides less resistance against progression of periodontal disease than a unit with a supraalveolar connective tissue attachment of normal length.

A long supraalveolar connective tissue attachment was established at the buccal aspect of mandibular premolars and molars in dogs by surgical removal of the marginal portion of the buccal alveolar bone after elevation of a muco‐periosteal flap. Attempts were made to minimize mechanical injury to the root cementum and the supraalveolar fibrous attachment during the surgical procedure. Contralateral, non‐operated teeth with a supraalveolar connective tissue attachment of normal length were used as controls. Following surgery, plaque control was initiated and maintained for 3 months by topical application of 0.2% chlorhexidine digluconate solution twice daily. During the following 6 months, the oral hygiene measures were abandoned and plaque was allowed to accumulate on both groups of teeth. In order to enhance plaque formation and to promote the development of subgingival plaque, cotton floss ligatures were placed at the entrance of the gingival sulci. The dogs were sacrificed 6 months after the initiation of the plaque accumulation period. The jaws were removed and histological sections prepared of test and control teeth including their surrounding periodontal tissues.

The histological analysis revealed that the plaque induced inflammatory lesion in the gingival connective tissue did not extend more apically in sites with a long supraalveolar connective tissue attachment than in sites with a supraalveolar fibrous attachment of normal length. A small but statistically significant loss of connective tissue attachment had occurred in both groups of teeth. This attachment loss, however, was similar in sites with a long supraalveolar connective tissue attachment and in sites with a supraalveolar fibrous attachment of normal length. These findings suggest that the loss of attachment in periodontal disease is unrelated to the presence or absence of the bony component of the periodontium.
Dentine hypersensitivity
Authors: Dowell P. , Addy M.
Published: July 2006

A large number of compounds have been used, apparently successfully, in the treatment of dentine hypersensitivity. For most, the mechanism or mechanisms of action are not clearly established, although uptake onto or into the dentine surface would appear a prerequisite for action. This study measured by fluoride probe analysis and atomic absorption spectrophotometry the uptakes of fluoride, strontium, tin, zinc, and potassium to powdered dentine and hydroxyapatite. With the exception of potassium, the uptake of all compounds increased as the concentration of the respective solutions increased. The uptake of potassium was negligible. The uptake of each compound was greater by dentine than hydroxyapatite; however, saliva pretreatment of both materials did not significantly alter the uptake of any compound. The mean maximum reaction of the metal salts with dentine or hydroxyapatite suggested that saturation was almost achieved for fluoride, strontium, and zinc. The uptake of tin was almost complete at all powder weights and would indicate a precipitation reaction of the metal salt onto the calcified materials. The results support the possibility of fluoride, strontium, tin, and zinc salts, by their affinity for dentine, exerting a direct or indirect action in dentine hypersensitivity. However, it is unclear how potassium nitrate has an apparently beneficial effect in the treatment of dentine hypersensitivity.
Salivary concentrations of steroid hormones in males and in cycling and postmenopausal females with and without periodontitis
Authors: Vittek J. , Kirsch S. , Rappaport S. C. , Bergman M. , Southren A. L.
Published: July 2006

Concentrations of testosterone, dehydroepiandrosterone, eslradiol, progesterone, 17α‐hydroxyprogesterone, and cortisol were measured in the saliva by radioimmunoassay. Saliva from male and cycling and postmenopausal female patients with and without periodontitis was studied.

It was found that salivary concentration of progesterone was increased in all patients with periodontitis. While testosterone was significantly increased in the female diabetic and non‐diabetic patients with periodontitis, no difference in its concentration was found in the saliva of non‐diabetic males with and without periodontitis. Salivary dehydroepiandrosterone was also increased in postmenopausal females with periodontitis. In contrast, estradiol was significantly decreased or not measurable in all patient groups with periodontitis. The concentration of cortisol and 17α‐hydroxyprogesterone showed no significant differences in postmenopausal patients with and without periodontitis. In addition, the salivary concentration of all hormones in postmenopausal females showed circadian variation. Moreover, results obtained in postmenopausal and ovariectomized females provided evidence for extragonadal production of sex steroid hormones in postmenopausal females.

The present results suggest that there is a relationship between the altered production of sex steroid hormones and the incidence of periodontal pathology.
Bacteriological studies of subgingival plaque in a periodontitis‐resistant population
Authors: Africa C. W. , Parker J. R. , Reddy J.
Published: July 2006

Differential darkfield microscopic examination of subgingival plaque samples from a community, which on clinical evidence had a contained gingivitis (mean probing depth 3.1 mm), revealed 35.7% spirochaetes and 7.4% motile rods.

In spite of persistent plaque deposits and a high proportion of spirochaetes, this isolated population in Namaqualand, South Africa, appears to be resistant to periodontitis.
Salivary IgA antibody to Actinobacillus actinomycetemcomitans in a young adult population
Authors: Smith Daniel J. , Ebersole Jeffrey L. , Taubman Martin A. , Gadalla Laila
Published: July 2006

Stimulated parotid salivas, collected from 162 young adults, were screened in ELISA Tor IgA antibody to Actinobacillus actinomycetemcomitans. Subjects with elevated levels of IgA antibody (HSA) were age‐ and sex‐matched with subjects with low antibody levels (LSA) for subsequent study. Infection with A. actinomycetemcomitans, elevated serum antibody levels to A. actinomycetemcomitans, and presence of multiple sites >5 mm were generally found only in the HSA group. There was a significant association between the presence of deep pockets and elevated serum antibody in these subjects. Thus, screening saliva for IgA antibody may be a useful, noninvasive technique to identify individuals with the potential to develop periodontal disease or those who are currently responding to an infection with A. actinomycetemcomitans.
Further evidence that tetracyclines inhibit collagenase activity in human crevicular fluid and from other mammalian sources
Authors: Golub L. M. , Wolff M. , Lee H. M. , McNamara T. F. , Ramamurthy N. S. , Zambon J. , Ciancio S.
Published: July 2006

Recently, a new mechanism was proposed to explain the therapeutic efficacy of tetracyclines in periodontal disease— that specifically these antibiotics directly inhibit the activity of collagenase (and possibly other collagenolytic enzymes) produced by the host tissues resulting in a reduced rate of collagen breakdown (Golub et al. 1983). In the current studies, the effect of tetracyclines (minocycline, doxycycline, tetracycline) on collagenolytic enzyme activity was examined in human periodontal pockets and in several animal systems. In the clinical studies, gingival crevicular fluid (GCF) was collected on filter paper strips from individual periodontal pockets, the volume measured with the Periotron 6000, and the Gingival Index and pocket depth scored immediately thereafter at the same sites. The strips were incubated with [3H‐methyi] collagen maintained in solution (or with 14C‐glycine labeled collagen Fibrils), and the radiolabeled collagen degradation products measured in a liquid scintillation spectrometer, Using the techniques of SDS‐PAGE and fluorography, the GCF was observed to generate collagen degradation products characteristic of those produced by mammalian collagenase, a finding consistent with previous studies. Both minocycline and tetracycline therapy reduced GCF collagenolytic activity about 70% during the initial weeks of treatment; the clinical parameters also showed improvements at the same time periods. This reduction in collagenolytic activity had largely regressed by 5 weeks after terminating tetracycline therapy and by 19 weeks after minocycline therapy, in the absence of other forms of periodontal treatment. In a preliminary study, 50 days of doxycycline treatment also reduced GCF collagenase activity, an effect which persisted for at least 2 months (but less than 1 year) after terminating its administration. In several studies involving experimental animals, the tetracyclines (1) in vivo, were found to reduce the pathologically excessive collagenase activity in gingiva and skin of diabetic rats; and (2) in vitro, directly inhibited the activity of collagenases from rat PMNL's and rabbit chondrocytes. The data in the current and our previous studies (Golub et al. 1983, Gomes, Golub & Ramamurthy 1984) continue to support the hypothesis that tetracyclines, by directly inhibiting collagenolytic enzyme(s) activity, may be therapeutically useful in treating diseases, such as periodontitis, characterized by excessive collagen breakdown.
Latex slide agglutination vs. ELISA system
Authors: Gargiulo Alphonse V. , Toto Patrick D. , Robinson John A. , Gargiulo Anthony W.
Published: July 2006

The extracts of clinically inflamed gingiva in fifty‐three patients with chronic periodontitis and in ten patients with clinically normal gingiva were tested for the presence of IgM rheumatoid factor. The identification of rheumatoid factor in such extracts was made using both the latex agglutination macroscopic slide test and the enzyme‐linked immunosorbent assay. Significant correlation was observed between the positive and the negative reactions of the latex slide agglutination test and the enzyme‐linked immunosorbent assay.
Binding of 3H‐Methyltrienolone (3H‐R1881) to androgen receptors in human gingiva
Authors: Vittek J. , Hernandez M. R. , Wenk E. J. , Rappaport S. C. , Southren A. L.
Published: July 2006

Binding of 3H‐Methyltrienolone (3H‐R1881) to cytoplasmic androgen receptor protein and its translocation into nuclei in human gingiva was demonstrated. 3H‐R1881 binds to androgen receptors with high affinity (Kd= 1.7−1.9 × 10−9 M) and low capacity (10–16 fmol/mg protein). The binding was specific for DHT binding sites and was destroyed by proteolytic enzymes (pronase and trypsin). These results suggest that 3H‐R1881 can be used as a ligand in combination with nonradioactive DHT to study androgen receptors in the gingiva.
Analysis of lymphocyte populations extracted from chronically inflamed human periodontal tissues
Authors: Seymour G. J. , Cole Karen L. , Powell R. N.
Published: July 2006

The current study was undertaken to characterize the lymphoid cell populations extracted from chronically inflamed periodontal tissues. Tissue was removed from 20 patients undergoing periodontal surgery. All patients had received repeated oral hygiene instruction and root planing prior to the surgery. The excised tissue was cut finely, digested in collagenase for 90 min, and then forced through a stainless steel grid to obtain a single cell suspension. T‐cells were identified by labelling with the monoclonal antibody UCHTI in an immunofluorescence assay. B‐cells were also identified in an immunofluorescence assay by the presence of surface membrane immunoglobulin as well as by labelling with the monoclonal antibodies FMCl, FMC4, and FMC7.

Eight patients had 3 mm or less loss of attachment while 12 patients had 5 mm or more loss of attachment. UCHTI+ve cells accounted for almost 50% of the lymphocytes (a mean of 49.3 ± 1.5%), while B‐cells identified by all three of the pan B‐cell markers (Smlg, FMC1, and FMC4) accounted for over 30% of the lymphocytes. There was no statistically significant difference between each group with any of the markers used. The vast majority of B‐cells (81.4%) appeared to carry the maturation antigen identified by the FMC7 antibody. Histologically some fragments of tissues were found to contain large numbers of plasma cells. Other fragments were predominated by lymphocytes, clusters of which had the enzyme profile of T‐cells while in other foci the lymphocytes had the enzyme profile of B‐cells. This finding may reflect the presence of different disease states within the surgical field. Caution should therefore be taken before extrapolating to individual disease sites.
The effect of subsampling sites within patients
Authors: Laster Larry L.
Published: July 2006

In recent periodontal research, multiple sites within patients have been utilized as the primary observations or sampling units. In the present study a simple approach for the single sample case was used to demonstrate the effect of site‐specific analyses when the patient is not treated as the sampling unit. This approach was shown to underestimate the variance of the mean value in question and thus, in tests of hypotheses concerning the mean, lowers artificially the p‐level or equivalently raises artificially the 1‐α confidence level of intervals.

The error introduced by this procedure increased when the number of actual primary random sampling units (the patients) was small, for this resulted in inappropriately lowered Student's tvalues. The error also increased as the number of sites used within patients increased and decreased slightly as the number of patients increased. From only six periodontal patients where six randomly chosen sites were observed for pocket depth in mm, a statistically significant (p<0.01) intraclass correlation was seen (ϱ1=0.31). If the 36 sites had been treated as independently distributed, a true probability of p(true)=0.27 would have been misread nominally as p(nominal)=0.05.
Activity of serum immunoglobulins G, A, and M to six anaerobic, oral bacteria in diagnosis of periodontitis
Authors: Tolo Kåre , Schenck Karl
Published: July 2006

The serum levels of IgG, IgA, and IgM‐antibodies to extracts of Bacteroides gingivalis, Bacteroides ureolyticus, Capnocytophaga ochracea, Eubacterium saburreum, Fusobacterium nucleatum and Selenomonas sputigena were measured by an enzyme‐linked immunosorbent assay (ELISA) in 50 subjects with a healthy periodontium, 10 patients with gingivitis, and 40 patients with periodontitis. In the healthy subjects, the levels of IgG and IgA‐antibodies to the extracts were positively correlated with age up to 20 years; after this age no further increase was observed in the mean levels of antibodies to the oral bacteria. A large majority of the patients with periodontitis had significantly increased levels of IgG and IgA‐antibodies to one or more of the bacterial extracts. By discriminant analysis of the data refering to all six extracts. 95% of the sera from the periodontitis group received a classification that only included 3% of the sera in the healthy group and 20% of the sera in the gingivitis group.

A simpler test based on the IgG and IgA‐antibodies to extracts of B. gingivalis and E. saburreum showed a sensitivity of 75% in detecting sera from the periodontitis group. In this test, 70% of the gingivitis sera and 90% of the sera from the healthy subjects were negative.
Morphological studies on periodontal disease in the cynomolgus monkey
Authors: Nalbandian J. , Brecx M. C. , Ooya K. , Kornman K. S. , Robertson P. B.
Published: July 2006

Histologic observations were made on the primate Macaca fascicularis in order to describe the features of both naturally‐occurring gingivitis and gingivitis present at non‐experimental sites when selected teeth were ligated to induce periodontitis. Semi‐thin sections of glutaraldehyde‐paraformaldehyde fixed, EDTA‐decalcified, and epon‐embedded specimens were used, supplemented by routine histologic methods.

The microscopic picture of the interdental areas was identical for the two types of gingivitis specimens and consisted of a chronic inflammatory reaction resembling the established lesion in humans. The highly infiltrated gingival tissue exhibited a predominance of plasma cells. Leukocytes were seen in pathways from the connective tissue, through the epithelium and to the surface of the plaque, and many neutrophils were interposed between the plaque and soft‐tissue. The apical extent of the junctional epithelium was at or slightly below the cemento‐enamel junction. Although perivascular inflammation was observed in the transseptal fiber region, the alveolar crest exhibited only evidence of normal bone remodelling.
Mirror symmetry of newly divided rat periodontal ligament fibroblasts in situ and its relationship to cell migration
Authors: Cho Moon‐Il , Garant Philias R.
Published: July 2006

A dramatic increase in proliferation of endothelial, paravascular cells, and PDL fibroblasts occurs during orthodontic tooth movement. The development of mirror symmetry in newly divided fibroblast daughter cell pairs in the rat periodontal ligament was studied.

Periodontal ligament fibroblasts loose their polarity and the normal organization of their organelles during cell division. Daughter cells, however, regain polarity and organization of their organelles to form mirror images of each other within 10 hours after cell division starts. Cellular polarity begins to appear with projection of a distal cell process at late telophase. Polarization is completed between late telophase and cytokinesis by shifting the RER and Golgi complex from the cleavage plane area to a juxtanuclear position facing the distal cell process. The majority of the newly divided fibroblasts formed mirror images in orientation and organization of organelles prior to cell migration. The distal cell process is the leading edge; i.e., the nuclear‐Golgi axis points toward the direction of movement.
Marginal soft tissue recessions with and without attached gingiva
Authors: Schoo W. H. , van der Velden U.
Published: July 2006

Changes in the position of the labial/buccal soft tissue margin of gingival recessions were investigated. In twenty‐five subjects, fifty‐two teeth without attached gingiva and fifty‐four teeth with attached gingiva were selected. On the average, changes were minimal over the five year period in both groups. Statistically significant loss of attachment was found in the group of teeth with attached gingiva. The validity of the assumption, that the presence of attached gingiva reduces the risk of further loss of attachment, appears to be questionable.
In vitro immunosuppression mediated by an extracellular polysaccharide from Capnocytophaga ochracea
Authors: Bolton R. W. , Kluever and E. A. , Dyer J. K.
Published: July 2006

The mechanism of immunosuppression produced by an extracellular polysaccharide (EP) from Capnocytophaga ochracea strain 25 (Socransky) was evaluated in vitro. Adherent (A), nonadherent (NA), and whole spleen cells (WS) from C57BL/6 inbred mice were pulsed with EP and combinations of cells evaluated for responsiveness to the T lymphocyte mitogen concanavalin A (Con A) by measurement of 3H‐thymidine uptake after 72 h of culturing. Binding of EP to spleen cells was evaluated by inhibition of 3H‐Con A binding after pre‐exposure of cells to EP. In addition, experiments were performed which attempted to block EP‐mediated suppression of responses to Con A by pre‐exposure of WS cells to 2‐mercaptoethanol (2‐ME), dithiothreitol (DTT), catalase, and indomethacin, all being known inhibitors of macrophage‐mediated immunosuppression. Significant suppression of responses to Con A occurred only when WS cells were pulsed with EP prior to exposure to the mitogen or when EP‐pulsed A cells were mixed with NA cells or WS cells prior to mitogenic stimulation. Pre‐exposure of NA cells to EP followed by mixing with untreated A cells or WS cells was comparatively ineffective in suppressing responses to Con A. EP bound to A cells to a higher degree than to NA cells as determined by inhibition of 3H‐Con A binding. Both 2‐ME and a combination of indomethacin and catalase blocked EP‐mediated immunosuppression, while preexposure of cells to DTT, catalase, or indomethacin alone was ineffective in blocking suppression. The results suggest that EP may exert its immunosuppressive activity through macrophages; however, the participation of suppressor T cells was not eliminated by these studies.
Simultaneous assessment of complement components C3, C4, and B and their cleavage products in human gingival fluid
Authors: Niekrash Christine E. , Patters Mark R.
Published: July 2006

Studies of the potential role of the complement system in the pathogenesis of periodontal disease have involved measurements of complement cleavage in gingival fluid obtained from lesions of periodontitis. Due to the limited amounts of gingival fluid available from periodontal lesions, these studies have been confined to assessment of single complement components in lesions with significant inflammation. This paper presents a description and an evaluation of reliability of an improved method of sampling and complement assessment by crossedimmunoelectrophoresis which permits measurement of C3, C4, B. and their conversion products in single gingival fluid samples as small as 0.2 μl. Gingival fluid collected on filter paper strips and serum applied to strips as controls were subjected to crossed‐immunoelectrophoresis using a multiple second‐dimension gel composed of a 2 cm wide slab of agarose with anti‐human B and anti‐human C3, followed by another 2 cm slab containing anti‐human C4 and antihuman transferrin (reference marker). Following drying and staining of the gels, the resultant precipitates were measured and the relative amount of each component and the percentage conversion of C3 determined.

Using both fresh and activated serum, this technique was found to have a variability within 10%. Stability of complement measurements in gingival fluid was determined by duplicate sampling of 26 lesions of periodontitis prior to periodontal therapy. No significant differences were found in any of the components measured suggesting that the method produced reliable results from clinical samples. These findings establish this method as a sensitive and reliable means of assessment of complement cleavage in single samples of gingival fluid. This technique should be useful for longitudinal measurements of changes in complement during induction or resolution of periodontal disease.
Ultrastructural observation on Langerhans cells in the rat gingival epithelium
Authors: Takehana Shigeki , Kameyama Yoichiro , Satoand Emiko , Mizohata Masanobu
Published: July 2006

The present study was carried out to investigate ultrastructurally Langerhans cells in the rat gingival epithelium. The gingivae of lower incisors of 15 Wistar rats were examined by electron microscopy. The results were as follows: Langerhans cells were observed mainly in the lower prickle‐cell layer of the gingival epithelium. On rare occasions Langerhans cells were also found in the basal and granular layers. The average number of Langerhans cells per 100 cells in the prickle‐cell layer was 1.0 cell. Usually Langerhans cells had clear cytoplasms and convoluted or indented nuclei, although sometimes the cells exhibited round nuclei. The clear cytoplasm contained a moderately developed Golgi apparatus and a small number of rough surfaced endoplasmic reticulum, free ribosomes, mitochondria, and lysosomes, but it lacked tonofilaments. Birbeck granules were often found in close vicinity of the Golgi apparatus. The average number of Birbeck granules per one Langerhans cell was 4.3 granules. The cell membrane of Langerhans cells had no junctional complexes like desmosomes. The degeneration of keratinocytes adjacent to Langerhans cells was observed in a few specimens.
Bone‐seeking radiopharmaceutical uptake as an indicator of active alveolar bone loss in untreated and surgically treated teeth in beagle dogs
Authors: Jeffcoat M. K. , Williams R. C. , Kaplan M. L. , Goldhaber P.
Published: July 2006

The use of bone‐seeking radiopharmaceutical uptake as an indicator of “active” alveolar bone loss was assessed in six beagle dogs. Periodontal surgery was performed in one‐half of the mouth in each dog in an attempt to assure a range of rates of bone loss in these animals. Radiographic and bone‐seeking radiopharmaceutical uptake measurements were taken prior to treatment and during a nine month post‐treatment period. A single measurement of uptake was compared to the rate of bone loss determined from repeated radiographs taken over a six month period subsequent to the uptake examination. Bone‐seeking radiopharmaceutical uptake was an accurate indicator of “active” bone loss as measured radiographically six months later in 83.7% of the teeth studied.
Effects of experimental diabetes mellitus on alveolar bone loss in periodontal disease‐susceptible mice
Authors: Johnson Roger B.
Published: July 2006

The purpose of this study was to determine the effects of experimental diabetes mellitus on alveolar bone in an animal predisposed to alveolar bone resorption, the STR/N strain of mice. Animals, aged twelve weeks, were rendered diabetic by an intravenous injection of streptozotocin, and bone loss was measured in the interdental septum between the first and second molar teeth. Prior to eighteen weeks, there was no consistent pattern of bone loss in either group. After eighteen weeks, bone loss in the diabetic group was significantly less (p<0.001) than in the control group. This situation was evident during the remainder of the thirty‐week study. Bone loss was a result of resorption of the alveolar crest resulting in an increased width of the transseptal fiber group. Alcian blue stain, pH 1.0, a histochemical marker for sulfated glycosaminoglycans, indicated a progressive decrease in bone matrix glycosaminoglycans in diabetic animals. However, intense alcian blue positive areas at the bone periphery suggested that glycosaminoglycans were not depleted in those areas. The study suggests that diabetes mellitus does not increase alveolar bone loss in susceptible animals, possibly because the diabetic condition was established subsequent to the initiation of alveolar bone resorption.
The possibility of measuring plaque growth in vivo within 24 hours
Authors: Quirynen M. , van Steenberghe D. , Vuylsteke M.
Published: July 2006

The utility of a planimetric method for measuring in vivo plaque growth on teeth within 24 hours was tested. A reproducible photographic technique was developed. With this technique color slides were made after plaque disclosure with neutral red 0.5% and enlarged up to 25 times natural size for tracing on paper. The percentage of tooth surface covered by plaque was calculated with a planimeter. To obtain a stable and interpretable staining of the plaque three dye applications were applied. The interpretation of the slides was only reproducible when the slides were examined the same day and with the use of a tooth outline. Under these conditions an intra‐examiner correlation coefficient of 0.999 was found. Furthermore, it was possible to detect significant differences in rate of plaque growth between two subjects within a time interval of four hours.
Mechanisms involved in the binding of IgG immune complexes to sections of inflamed gingiva
Authors: Kristoffersen T. , Johannessen A. C. , Tønder O. , Matre R. , Skaug N.
Published: July 2006

The binding of particulate (sensitized sheep erythrocytes= EA) and soluble (horse radish peroxidase (HRP)‐anti‐HRP) IgG immune complexes to cryostat sections of inflamed human gingiva was studied. EA bound preferentially to inflammatory cell infiltrates in all biopsy specimens, and HRP‐anti‐HRP complexes were found to bind to the surface of mononuclear cells. Binding of EA was abolished by treatment of cryostat sections with 1 mM periodic acid (30 min) or 4% formaldehyde (10 min). Binding was also abolished by exposure of sections to cold ethanol for 5 min. No binding of fluorescein labelled, heat aggregated human IgG to sections of washed and ethanol‐fixed biopsies of inflamed human gingiva was observed. Results of inhibition experiments with rabbit and human native or heat aggregated IgG, rabbit and human IgG Fc and IgG F(ab′)2 fragments, human IgG 1 and IgG2, mildly reduced and alkylated human IgG and with rabbit anti‐human Clq, indicated that the binding is not due to activated C1 or to the presence of rheumatoid factors. Our findings are consistent with the concept that the binding is due to the presence of IgG Fc receptors (IgGFcR) on mononuclear cells. Ethanol fixation of specimens compromises any conclusions regarding IgGFcR activity in the tissues.
Gingival crevicular fluid antibody to oral microorganisms
Authors: Smith D. J. , Gadalla L. M. , Ebersole J. L. , Taubman M. A.
Published: July 2006

Gingival homogenates (GH) from periodontally diseased subjects were assayed for total immunoglobulins and for antibody to periodontopathic bacteria. Antibody activity in static crevicular fluid (SCF) and GH was compared using an ELISA. Expression of IgG antibody activity per μg IgG or per unit volume of fluid was highly correlated. Antibody activity in 46 SCF and 29 GH from diseased areas in localized juvenile periodontitis and adult periodontitis subjects were compared with serum antibody activity. Twenty of the 46 SCF contained significantly higher concentrations of IgG antibody activity to periodontopathic organisms than found in the respective sera. In addition, 87% of the GH contained higher concentrations of IgG antibody than the corresponding SCF. Variations in IgG antibody concentrations were often seen in different sites from the same subject. GH IgG antibody showed a range of specificities no broader than found in serum from the corresponding subjects when compared against a battery of organisms. Elevated IgA antibody concentrations were also observed in GH. These data support the notion that a significant portion of antibody found in the GH and SCF of periodontally diseased subjects may be locally derived.
Interaction of phenytoin and inflammation induces gingival overgrowth in rats
Authors: Do Nascimento Aparecido , De Castro Barreto Rosimar , Bozzo Lourenço , De Almeida Oslei Paes
Published: July 2006

In adult male Wistar rats (Rattus norvegicus albinus) gingival irritation provided by means of wire silk ligatures around the cervix of first left lower molars, for a duration of 77 days, caused gingival inflammatory changes. In the rats receiving also daily one i.p. injection of sodium 5,5‐diphenythydantoinate (phenytoin), during 70 days, there was no macroscopical change of the gingiva of non‐ligated first right lower molars. However, in the first left lower molars, the association of silk ligature‐plus‐phenytoin administration elicited gingival overgrowth. The rat was seen as a satisfactory animal model for studies of phenytoin‐induced gingival changes.
An in vivo model to study migration of cells and orientation of connective tissue fibers in simulated periodontal spaces
Authors: Aukhil I. , Iglhaut J. , Suggs C. , Schaberg T. V. , Mandalinich D.
Published: July 2006

An in vivo model is described to study the migration of cells into experimental “periodontal” spaces and the influence of the geometry of substrata on cell and fiber orientation. Roots of molars and cylinders of bone (from femur and tibia) were obtained from Sprague‐Dawley rats. All attached soft tissues were removed from the bone cylinders (BC) and roots by planing with curettes followed by collagenase treatment. The roots and BC were divided into experimental (roots in bone cylinders to simulate tooth‐socket relationship) and control groups. Following citric acid treatment for 3 min, pairs of experimental and control specimens were implanted subcutaneously in 20 Sprague‐Dawley rats. Histologic examination was done 3 and 6 weeks after implantation. Connective tissue cells had migrated into the experimental spaces of both experimental and control specimens at 3 and 6 weeks. The cell and fiber orientation varied between the groups, and a tendency towards functional orientation of fibers was seen in some experimental and control specimens. The orientation of connective tissue fibers appeared to be influenced also by the spatial relationship of substrata to which they attach.
New attachment formation on citric acid treated roots
Authors: Isidor Flemming , Karring Thorkild , Nyman Sture , Lindhe Jan
Published: July 2006

The present investigation was carried out in order to examine if citric acid treatment would promote new attachment formation on roots with a reduced but healthy periodontium. In each of 4 monkeys, periodontal tissue breakdown was induced around a maxillary and mandibular central incisor and second premolar or first molar by placing orthodontic elastic ligatures around the teeth. The ligatures were kept in situ until about 50% of the supporting tissues had been lost. Three months following removal of the ligatures the crown of the teeth was resected. The pocket epithelium and subjacent granulation tissue were excised and the periodontitis involved part of all roots was root planed using a diamond bur. Half the number of the teeth (7 teeth, i.e. II test roots) were treated by topical application of citric acid at pH 1 for 3 minutes. All roots were covered with a mucosal flap. The animals were sacrificed after 3 months of healing. The jaws were removed and tissue blocks containing the roots and their surrounding tissues were processed for embedding in paraffin. Serial sections, 8 μm thick, were cut in mesio‐distal direction for microscopic analysis. Six citric acid treated roots and 6 noncitric acid treated roots penetrated the covering soft tissue flap within the first week of healing. The microscopical analysis disclosed that in all roots new cementum with inserting collagen fibers had formed in the apical portion of the previously periodontitis involved surfaces. In those control roots, which for the entire length of the study remained covered by the oral mucosa, the coronal extension of this newly formed fibrous attachment amounted to an average of 1.0 mm with a range between 0.1 mm and 2.6 mm, and in the corresponding test roots 1.1 mm with a range between 0.1 mm and 2.2 mm. The length of the newly formed connective tissue attachment was significantly smaller in those test and control roots which had penetrated the soft tissue flap during healing than in those which remained covered throughout the study. No statistically significant difference was found between citric acid and non‐citric acid treated roots with respect to the amount of newly formed connective tissue attachment.
Blood flow and periodontal destruction in normal and atherosclerotic rhesus monkeys
Authors: Johnson Georgia K. , Squier Christopher A.
Published: July 2006

The effect of atherosclerosis on alveolar bone blood flow and several periodontal tissue parameters was examined in the rhesus monkey. Five adult monkeys were maintained on an atherogenic diet for 54 months and the remaining five animals were fed a normal diet. Prior to death, radiolabelled microspheres were used to measure bone blood flow in the posterior regions of maxilla and mandible. Tracings were made of mesio‐distal histological sections through the premolar and molar teeth in each jaw and measurements were taken of bone area, crestal bone height, level of epithelial attachment, and number of osteoclast nuclei. The atherosclerotic monkeys showed a significant decrease in all these parameters compared to controls. Blood flow was significantly lower in the maxilla of atherosclerotic animals, and there was a significant correlation in both groups between reduced blood flow and loss of crestal bone; in the atherosclerotic monkeys reduced blood flow was also significantly correlated with a more apical junctional epithelia. It is possible that reduced blood flow such as that associated with atherosclerotic disease may render the periodontal tissues more susceptible to destruction by etiological agents such as plaque.
The quantification of individual proteins in crevicular gingival fluid
Authors: Marcus E. R. , Jooste C. P. , Driver H. S. , Hattingh J.
Published: July 2006

The aim of the present study was the quantification of proteins present in crevicular fluid obtained from individual sulci, and to this effect simplified micromethods for the quantification of individual proteins were developed. Unstimulated, resting crevicular fluid from healthy crevicular spaces (i.e. in the absence of clinically detectable inflammation) of dogs and humans was collected for 3 minutes, either in microcapillary glass tubes or with the aid of filter paper strips. Quantification of proteins was done by radial immunodiffusion without the pooling of samples or by immunoelectrophoresis, without eluting from the papers. The concentrations of albumin and fibrinogen in crevicular fluid so determined proved to be significantly lower than plasma concentrations. These results strengthen the concept that capillary dynamics in healthy gingivae are similar to those in general tissue capillary beds and that gingival fluid is a plasma transudate. However, due to ever present sub‐clinical inflammation and other factors, it is improbable that fluid from even healthy sulci is a true transudate.
Eosinophils during developing periodontal disease of rats
Authors: Bertã J. M. , de Almeida O. P. , do Nascimento A. , Novaes and P. D. , Bozzo L.
Published: July 2006

Experimentally provoked gingival inflammation in rats presented eosinophils in the cellular infiltrate. Eosinophil numbers increased progressively to a peak at 30 days, and subsequently there was no quantitative alteration. Initially eosinophils were found in inflammed areas underneath the gingival epithelium and in later periods were more numerous in the deep corium among the collagen fibers. The extracytoplasmic granules were among the collagen fibrils and close to fibroblasts which phagocytosed collagen. It is suggested that eosinophils participate in the experimentally induced periodontitis in rats, and that they can act on the metabolism of rat gingival collagen.