bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of the morphological and chemical nature of dental surfaces on the migration, attachment, and orientation of human gingival fibroblasts in vitro
Authors: Pitaru S. , Gray A. , Aubin J. E. , Melcher A. H. 
Published: July 2006

The influence of four different dental surfaces, demineralized dentine (DD) and cementum (DC), and nondemineralized dentine (ND) and cementum (NC), on the migration, attachment, and orientation of human gingival fibroblasts (HGF) was tested in an in vitro system. The root surface of porcine teeth was planed using a curette. The cementum was removed from half of the teeth and the roots planed again. Slices of root ∼ 150 μm thick were obtained from the roots. Half of the root slices in each group were partly demineralized in 18% EDTA, pH 7.4. Pairs of root slices were added to each of 20 culture dishes containing 5‐day‐old confluent cultures of HGF. The attachment of HGF to the four types of attachment surfaces (DD, ND, DC, & NC) and the formation of oriented sheets of cells extending between the periphery of the slices and the bottom of the dish were assessed quantitatively after 1, 3, and 6 days of culture. In a second experiment, 12 cultures comprising demineralized and non‐demineralized root slices were examined at 1, 3, and 6 days using SEM. In a third experiment, cultures comprising DC slices were prepared as described and examined for 24 h by time lapse microscopy.It was found, first, that cells started to migrate and attach to the periphery of the slices immediately following the placement of slices. Cellular bridges extending between the attachment surface and the floor of the dish developed during the first 24 h of culture and gradually increased in number and in size throughout the experimental period. Second, partially‐demineralized surfaces were more effective in stimulating cell migration and attachment and cell orientation than were non‐demineralized surfaces, and demineralized dentine surface were more effective than were demineralized cementum surfaces in this regard. These results further elucidate previous findings regarding the enhancing effect of partial demineralization of dental surfaces on wound healing in vivo and suggest that demineralized dentine may provide the most effective dental surface in this respect.
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.
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.
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.
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.
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.
Distribution of Capnocytophaga in periodontal microfloras
Authors: Holdeman Lillian V. , Moore W. E. C. , Cato Elizabeth P. , Burmeister J. A. , Palcanis K. G. , Ranney R. R. 
Published: July 2006

Concentrations and incidence of capnocytophagae were determined in 559 samples from persons with moderate (MP), severe (SP), and localized juvenile (JP) periodontitis; persons with healthy gingiva; and children and adults participating in experimental gingivitis studies. Capnocytophagae were most frequent in four children who participated in an experimental gingivitis study. The lowest incidence and concentrations were found in subgingival floras of affected sites of persons with MP, SP, or JP.Statistically significantly (P = 0.02 to 0.05) higher proportions of capnocytophagae were found in a) sites in children with gingival index (GI) of 0 than similar sites in adults, b) sites in children with GI of 2 than GI of 0, c) supragingival and subgingival samples from healthy persons than subgingival samples from SP, d) supragingival samples from SP than subgingival samples from SP and from JP, e) supragingival samples from MP than subgingival samples from SP.These data from cross‐sectional studies indicate that the significance of capnocytophagae in the etiology of periodontal diseases has been overestimated. Their higher incidence and proportional concentrations in healthy sites and supragingival floras than in the subgingival sulcus of sites with attachment loss would indicate that they are not as competitive in the sulcus as they are on the exposed tooth surface and would argue against their being active agents of these types of destructive periodontal diseases. However, preliminary data from three persons (MP) participating in longitudinal studies show that in one of the three persons the levels of C. ochracea increased to 10 to 20% of the flora in subgingival samples in which there had been at least a 2 mm loss of attachment within three months. No capnocytophagae were isolated from similar sites in one other person, and they constituted 6% of the flora in the breakdown site in the third person.
Treatment of periodontal disease in beagles with lodoxamide ethyl, an inhibitor of mast cell release
Authors: Jfffcoat M. K. , Williams R. C. , Johnson H. G. , Wechter W. J. , Goldhabfr P. 
Published: July 2006

The effect of lodoxamide ethyl, a mast cell release inhibitor on the progression of chronic periodontal disease in beagles was examined. Twelve adult female beagles with naturally occurring periodontitis were studied. Following a six‐month pretreatment baseline period, six dogs were given 20 mg/kg lodoxamide ethyl orally for a twelve‐month treatment period. In addition, at the beginning of the treatment period one‐half’ mouth in each dog was treated with periodontal flap surgery. Thus, the experimental design allowed a comparison of the progression of periodontitis about premolar teeth in a pretreatment period with progression of periodontitis in a treatment period in which one of the following treatment protocols was used: no treatment, teeth treated with periodontal flap surgery, teeth treated with lodoxamide ethyl administration, and teeth treated with lodoxamide ethyl administration plus periodontal flap surgery.In the systemically untreated dogs the rate of alveolar bone loss increased in the treatment period, compared to the baseline pretreatment period about both teeth not treated locally and teeth treated with flap surgery. In contrast, the rate of alveolar bone loss was significantly reduced in the treatment period in those dogs administered lodoxamide ethyl daily. Lodoxamide ethyl administration combined with flap surgery was more effective than lodoxamide ethyl alone. Tooth mobility significantly increased in those dogs administered lodoxamide.The data indicate that administration of an orally active mast cell release inhibitor can decrease the rate of alveolar bone loss which occurs in beagle periodontitis. However, the clinical usefulness of this pharmacologic agent is not clear due to the increased tooth mobility which occurred in this study. Since the principle effect of lodoxamide ethyl is believed to be on mast cell degranulation, a role for mast cells in beagle alveolar bone loss is implied.
Histochemical demonstration of lectinbinding sites and keratin in inflamed human gingiva
Authors: Murase N. , Hosaka M. , Takai Y. , Tanimura T. , Mori M. 
Published: July 2006

Histochemical demonstration of lectin‐binding sites and keratin peptides in gingival epithelia was reported and differences in staining and distribution were compared to inner and outer gingival epithelia.Gingival epithelia on the outer side exhibited zonal or regional distributions of lectin‐binding, and the cytochemical staining was generally found in the cell coat and intercellular materials. Keratin protein was found frequently in the spinous cell, infrequently in the basal cells, and not at all in the superficial layer. The sugar residues in the cell coat of gingival epithelia probably were mannose, galactose, N‐acetyl‐galactosamine, and N‐acetyl‐glucosamine.The inner side of the epithelia, crevicular, and pocket epithelia were characterized by irregular and incomplete staining for lectins. These epithelia also displayed less keratin staining compared to the outer gingival epithelia. These findings suggest the possibility of depolymerization of glycosaminoglycans in the cell coat by enzymes of either pocket bacterial origin or host tissue origin.