bluuebunny/crossref_metadata_2025 huggingface dataset:
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.
Neutrophil chemotaxis in families with localized juvenile periodontitis
Authors: Van Dyke T. E. , Schweinebraten M. , Cianciola L. J. , Offenbacher S. , Genco R. J.
Published: July 2006

Localized juvenile periodontitis (LJP) is characterized by severe, early onset alveolar bone loss, localized to the first molars and incisors and a high prevalence of infection with Actinobacillus actinomycetemcomitans and associated neutrophil functional abnormalities. Due to the frequent occurrence of this condition in families, it was the purpose of this investigation to determine the association of neutrophil chemotaxis abnormalities and clinical periodontal disease in families with LJP. Twenty‐two families were studied in which the proband was selected based upon presentation of LJP. All siblings were examined for the presence of LJP and neutrophil chemotaxis was measured on all subjects. The results indicate that there is a high association of LJP and neutrophil chemotaxis disorders and that this association is consistent along family lines. Specially, in families in which the proband exhibits a neutrophil chemotaxis disorder, all affected siblings (LJP) also exhibit depressed neutrophil chemotaxis, whereas, non‐affected siblings beyond the age of puberty have normal neutrophil chemotaxis. On the other hand, in families where the proband (LJP) exhibits normal chemotaxis, both normal and affected siblings exhibit normal chemotaxis. The finding among families with LJP that some exhibit neutrophil chemotactic depression and others exhibit normal neutrophils suggests heterogeneity of LJP. Accordingly, it is proposed that there is a syndrome of familial localized juvenile periodontitis with depressed neutrophil chemotaxis and another form of familial localized juvenile periodontitis with normal neutrophil chemotaxis. The chemotaxis disorder and LJP occur in nearly one‐half of the siblings in families with LJP. which is consistent with a dominant trait. however, multigenerational studies are necessary to determine the mode of inheritance. Hence, neutrophil chemotaxis is a disease marker which can be used in genetic studies of familial LJP with depressed neutrophil chemotaxis. Furthermore, prepubertal siblings often exhibit defective neutrophil chemotaxis in the families in which the proband exhibits such a defect. Since the prepubertal siblings are not affected by clinically detectable LJP, the finding of neutrophil chemotactic depression in these children further suggests that the neutrophil chemotactic defect is genetic in origin, precedes and may predispose to localized juvenile periodontitis.
Helper and suppressor T cells in periodontal disease
Authors: Stashenko P. , Resmini L. M. , Haffajee A. D. , Socransky S. S.
Published: July 2006

The ratio of helper (T4+) to suppressor (T8+) T cells was determined in a population of periodontitis patients and in normal subjects. Although patients as a group were found to have the same T4/T8 ratio as normal individuals, that subgroup of patients previously identified as T cell low responders to oral microorganisms exhibited a relative increase in circulating suppressor T cells. Conversely, unusually low T4/T8 ratios were predictive of low level T cell proliferative responses generated against 7/12 oral microorganisms tested. Patients with low T4/T8 ratios had significantly more redness and bleeding on probing than did those with high T4/T8 ratios, but did not differ with respect to plaque, pocket depth, attachment loss, or episodes of disease activity. These results extend previous observations concerning the relationship between the in vitro T cell response to oral microorganisms and gingival inflammation.
Necrotizing ulcerative gingivitis in beagle dogs
Authors: Maltha J. C. , Mikx F. H. M. , Kuijpers F. J.
Published: July 2006

A new modification of the Warthin spirochete staining method was developed to study at the light microscopic level the distribution of spirochetes in gingival tissues of beagle dogs with induced necrotizing ulcerative gingivitis. Spirochetes were present in cellular exudate at ulcerated sites, in edematous epithelium in the vicinity of ulcerations, and in intact sulcular epithelium. They did not appear to penetrate connective tissues via the ulcerations. These observations suggest that, in the etiology of NUG, spirochetes play a role in the initiation of the pathologic process by penetration of the intercellular spaces in the epithelium.
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.
Comparative study of six random oral spirochete isolates
Authors: Cheng S.‐L. , Siboo R. , Chin Quee T. , Johnson J. L. , Mayberry W. R. , Chan E. C. S.
Published: July 2006

Six anaerobic oral spirochetes designated strains a, b, c, d, e, and e’ were isolated randomly from periodontal pockets and were maintained in pure culture. The strains were found to belong to the genus Treponema. All strains were similar in cultural, morphological, biochemical, and physiological properties with the exception of the following features: strains c and d were more fastidious nutritionally for sodium bicarbonate as a medium supplement than the other strains; they differed in the number of axial fibrils; and they were also serologically distinct from strains a, b, e, and e’ by agglutination tests and fluorescent immunoassays. However, DNA homology studies indicated that all the isolates were strains of Treponema denticola with divergent phenotypic and serological properties. Serovar a and serovar c, representing two different serogroups, have been deposited in the American Type Culture Collection with the accession numbers ATCC 35405 and ATCC 35404, respectively.
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.
Effect of periodontal therapy on salivary enzymatic activity
Authors: Zambon Joseph J. , Nakamura Masakazu , Slots Jorgen
Published: July 2006

This study determined changes in the levels of enzymes in whole mixed saliva of adults following periodontal therapy including two or more sessions of meticulous periodontal scaling and root planing and 1 g/day of tetracycline‐HCI for 14 days. Clinical variables assessed at baseline and 2 weeks after treatment included Gingival Index, Plaque Index, periodontal pocket depth, and gingival crevicular fluid flow. Subgingival specimens obtained from the deepest periodontal pocket in each quadrant were analyzed for Bacteroides gingivalis and Bacteroides intermedius using indirect immunofluorescence microscopy and for bacterial morphotypes using bright light phase contrast microscopy. The enzymatic profile of unstimulated whole mixed saliva was determined using the API ZYM and API ZYM AP micromethod systems.

Periodontal treatment significantly reduced gingival inflammation and the proportions of subgingival black‐pigmented bacteroides and motile organisms. However, the Plaque Index and total salivary bacterial counts remained virtually unchanged. Treatment also resulted in reduced salivary levels of caprylate esteraselipase, leucine, valine, and cystine aminopeptidases, trypsin, β‐galactosidase, β‐glucuronidase, and β‐glucosidase.

The present study indicates that the efficacy of periodontal treatment may be readily monitored by changes in levels of activity of specific enzymes in whole saliva.
Basal cell characteristics in human oral epithelium adhered to the tooth in vivo and to and inert substrate in vitro
Authors: Salonen Jukka
Published: July 2006

Basal cells were immunocytochemically localized with a monoclonal anti‐cytokeratin antibody in the human masticatory cpithelium. The antigen was also found in the junctional epithelium and in the epithelial rests of Malassez in vivo, as well as in the cells growing along a Milliporea filter under a mucosal explant in vitro. The equivalent expression of the basal cell specific antigen in the cells adjacent to the tooth in vivo and along the filter in culture suggests that inert substrates as such or through the extracelluiar matrix synthesized in between, have an influence on the course of epithelial differentiation. This was further supported by the finding that the cells in contact with the filter attained basal cell appearance and Incorported 3H‐thymidine. However, there was no direct corrclation between the expression of the specific antigne and the event of cell proliferation. The antigen was associated with the pluripotency rather than with an apparent function of the positive cells.
A comparison of fibronectin and laminin binding to undemineralized and demineralized tooth root surfaces
Authors: Karp Wayne , Sodek Jaro , Aubin Jane E. , Melcher Antony H.
Published: July 2006

To determine the effect of altering the nature of the surface of the roots of teeth upon selective attachment of specific cell types, we have studied the binding of fibronectin (FN) and laminin (LN) to both undemineralized and demineralized root surfaces using a modified direct ELISA. Discs of dentine with the cementum removed were prepared from porcine premolar roots and incubated with various concentrations of FN or LN. The amount of attachment protein that binds to the dentine surface was determined using specific antibodies. It was found that FN binding was two‐fold greater on demineralized compared to undemineralized root surfaces. Healing the demineralized discs increased FN binding, whereas bacterial collagenase treatment essentially abolished binding, suggesting that FN binding occurred to exposed collagen fibres. In contrast, FN binding on undemineralized discs was unaffected by heat or collagenase treatment. Pronase treatment eliminated FN binding to demineralized and to undemineralized discs, whereas 4M guanidine hydrochloride extraction increased binding lo undemineralized discs, indicating that a non‐collagenous protein on Ihe undemineralized surface may bind to FN, Studies with LN showed a two‐fold greater binding of LN to undemineralized compared to the demineralized roots. These results indicate that surface treatment of exposed roots may be used to promote the adhesion of specific attachment proteins and thereby promote selective attachment of cells to tooth root surfaces.
The periotron gingival crevicular fluid meter
Authors: Van der Bul P. , DREYER W.P. , GROBLER S.R.
Published: July 2006

The present study was undertaken to compare the calibration curve of the periotron* (HAR‐6000) with those of two earlier models (HAR‐600) instrument, which was found to be appreciably more sensitive in detecting small volumes of fluid than the two older models, is curvilinear in shae while the latter two models display linear calibration characteristics Calibration curves were also obtained for one of the HAR‐600 models with the periopaper strip inserted up to and beyond the manufactures recommendations. The results obtained in this case differed from those published by others. Using fluids possessing different dielectric dissipation constants, calibration curves were determined for the HAR‐6000 model over a wide range of volumes, The calibration data obtained best fitted quadratic functions and the relative positions of the curves on the axes are in the correct relationship to their dielectric constants Inter‐instrument and other variations have once more stressed the importance of individual instrument calibration by uers.
Gingival crevicular fluid myeloperoxidase at periodontitis sites
Authors: Smita Q. T. , Hinrichs and J. E. , Melnyk R. S.
Published: July 2006

This investigation was undertaken to determine the relationship between the amount of the polymorphoruclear leukocye (PMN) cnzyme mycloperoxidasc (MPO) in gingival crevicular fluid (GCF) collected from periodontius sites before and after root planning and (1) gingival drsease status described by clinical indices. (2) the quantity of GCF. and (3) differential dark‐field coums of Subgingival plaque microorganisms. Similar measurements except dark‐field microbial counts, were made at sites with minimal signs of periodontal disease. Higher levels of GCF MPO occurred at periodontals sites. Reduced enzyme activity fooled instrumentation therapy. The reduced enzyme activity, however, was not specifically associated with decreases in clinical indices. GCF MPO was only weakly dependent of GCF volume Consequently a major portion of the greater GCF MPO observed before root planning reflected a characteristic of the lesion other than a difference in GCF volume. Before therapy more GCF MPO was noted at sites with a greater number of subgingival plaque microorganisms. However, there was no relationship between GCF MPO and the proportion of spirochetes, mobile and rod forms in the samples. These data support the conclusion that the quantity of GCF MPO reflects factors other than those associated with clinical parameters commonly used to assess inflammatory periodontal disease.
The in vivo fractional rate of gingival collagen production in non‐diabetic and diabetic rats
Authors: Schntir M. , Imberman M. , Ramamurtiiy N. , Golub L.
Published: July 2006

A new approach (pool‐expansion) has been applied for quantifying the in vivo fractional rate of gingival collagen production. This approach obviates a major shortcoming inherent in a lraditional tracer approach; decreasing specific radioactivity S. R., DPM/μg proline of tissue free‐Phlproline oocurring throughout the interval during stuch production is meausured, Poolexparision, involving the injection of excess unlaheled proline concomitant with a tracer amount of nidiotabeled proline, has been judged successful for incisor gingiva of non‐diabetic control rats by the following enteria. (I) the S. R. of gingival tree‐PHlproline remained constant from 0.5 to 2 h after Phlproline anjection and (2) during this interval, radiolabeled collagen Phlhydroxyprobne S. R. inereised linearly in contrasl pool‐expansion in gingiva of diabetic rats was less successful 0.5 h after injection, the S. R. of gingival free S. R. of gingival freep‐Phlproline was less than that after 2 h. indicating incomplete pool‐expansion at 0.5 h.

For meisor gingiva of non‐diabetic control rats, the fractronal rate of collagen production 1–1% a day is slouer than that in rat skin, For incisor gingiva of diaberic rats, the fractronat rate in reduced by 65%
Radioautographic analysis of 3H‐fucose utilization by fibroblasts of the periodontal ligament
Authors: Cho Moon‐IL , Garant Philias R.
Published: July 2006

The secretion of 3labeld glycoproteins from periodontal ligament fibroblasts was, studied by light and electron microseopic radioautography. At 5, 10. and 20 minutes after intravenous injection, 3H‐fucose was concentrated in Golgi cisternae and saccules. By 35 minutes, the label was dispersed to the cell periphery and extracellular matrix. At 8 hours after injection, almost all of the radioactive label was associated with the cell surface or the adjacent extracellular matrix. Labeled glycoprotein was contained in collagen secretion granules and appeared to be relesasd simultaneousley with the collagen precursors The distribution of 3H‐fucose labeled material was uniform across the periodontal ligament.
Initial characterization of neutral proteinases from oral spirochetes
Authors: Uitto V.‐J. , Chan E.C.S. , Chin Quee T.
Published: July 2006

Intermediate size oral spirochetes were isolated and cultured from subgingival plaque of periodontitis patients utilizing a membrane separation and rifambin selection technique. Neutral salt extracts of the spirochetes were assayed for proteolytic activity against collagen types I and IV, gelatin, and synthetic elastase and trypsin substrates. Type IV collagen obtained from lens capsule basement membrane was degraded to small peptides by the spirochete proteinases. No marked degradation of type I collagen was found when incubations were performed at 25°C. The extracts were able, however, to activate latent collagenase obtained from human gingival fibroblasts and to degrade further the ¼ and ¾ fragments resulting from the collagenase cleavage. Denatured collagen was also degraded by the extracts. High trypsin‐Iike activity and relatively lower elastase‐like enzyme activity were also present in spirochete extracts. The results show that oral spirochetes have a potential for degradation of several proteins and that they may, therefore, have an active role in tissue destruction during periodontal disease.
Glycogen in human cementoblasts and PDL fibroblasts
Authors: Yamasaki A. , Rose G. G. , Pinero G. J. , Mahan C. J.
Published: July 2006

Healthy human periodontal ligaments (PDL) attached to 22 tooth roots (7 nonfunctioning third molars, 3 functioning first molars, and 12 functioning first premolars) were obtained from 20 patients between 10 and 67 years of age (mostly second and third decades) and examined by transmission electron microscopy. The collagen‐producing cells (CPC) of the attached PDL were the cementoblasts and superjacent fibroblasts. A prominent accumulation of glycogen particles, confirmed by staining with periodic acid‐chromic acid‐silver methenamine, could be detected easily in the CPC of all sections obtained from all age groups and different kinds of teeth. The glycogen was most pronounced in the cementoblasts and was gradually reduced in those fibroblasts lying progressively more distant from the cementum. AcPase‐positive lysosomal bodies sometimes were found within or fused with the clusters of glycogen particles, i.e., alpha particles. Occasionally, extracellular bubble‐like structures with scattered glycogen particles were observed, suggesting the sequestration of unused glycogen. These findings of glycogen accumulation are presumed to be indicative of an anaerobic condition in the junctional area of cementum and PDL of human teeth.
Hydroxy fatty acids and prostaglandin formation in diseased human periodontal pocket tissue
Authors: Elattar T. M. A. , Lin H. S. , Killoy W. J. , Vanderhoek J. Y. , Goodson J. M.
Published: July 2006

The lipoxygenase and cyclooxygenase products of arachidonic acid (AA) metabolism are known to play a key role in the development of inflammatory signs and symptoms. Periodontal pocket tissues (PPT) provide an ideal model to study the nature of mediators of inflammation in periodontal disease. Eight individual PPT samples were obtained from patients with advanced periodontitis and incubated separately with 14C‐AA. The tissue lipid extracts were analyzed by means of TLC and HPLC. It was found that PPT in all samples metabolizes AA mainly through the lipoxygenase pathways and that 12‐HETE and 15‐HETE are the major lipoxygenase products formed. Cyclooxygenase products PGE2, TXB2, and 6‐keto‐PGF1α were detected in much smaller amounts than the lipoxygenase products. Since both lipoxygenase and cyclooxygenase products are associated with inflammatory processes, the findings suggest that in treatment of inflammation in periodontal disease, drugs which inhibit the formation of both lipoxygenase and cyclooxygenase metabolites of AA would be more beneficial than those which inhibit only the cyclooxygenase products, PGs.
The vasculature of the rat molar gingival crevice
Authors: Weekes W.T. , Sims M.R.
Published: July 2006

The vascular architecture of the gingival crevice around rat molars was investigated using the SEM vascular casting technique. The crevicular plexus consisted of two major vascular arrangements. The first was a planar network immediately subjacent to the crevicular epithelium extending from the crest of the free gingival margin down to the epithelial attachment. Arterial supply to the planar network came from the gingiva proper, but venous drainage from the plexus was directed into the periodontal ligament plexus as well as the deeper gingival vessels. The second major arrangement was a row of twisted vascular loops sited in the middle annular third of the crevice on the buccal and lingual. These loops exhibited a more complex vascular arrangement in the col and occupied most of the volume of the col tissue. The planar network in the interproximal col region narrowed to a thin band adjacent to the epithelial attachment. The morphological arrangements described in this project modify the description of Kindlova and Matena (1962) which has been accepted as a model for vascular architecture of the gingival crevice.
The effect of citric acid on the healing of periodontal ligament‐free, healthy roots, horizontally implanted against bone and gingival connective tissue
Authors: Dreyer W. P. , VAN Heerden J. D.
Published: July 2006

Edentulous sites were created in four adult baboons by prior extraction of all premolars. Amputated healthy molar roots were implanted horizontally into shallow grooves cut into the alveolar bone at these sites so that one side of the root faced gingival connective tissue and the other bone. Prior to implantation the roots were planed to remove all periodontal investing tissue and were demarcated by a circumferential groove into two portions. One portion was treated with citric acid (pH 1) for 3 minutes, thus creating side‐by‐side experimental and control sites facing both bone and soft tissue. The experimental sites were randomly distributed between apical and coronal root ends and observation periods of 4, 8, and 12 weeks were obtained. Efforts were made to reduce infection at the implantation site by the use of topical and parenteral antibiotics. After sacrifice the tissues were processed for routine light microscopy. Histometric analysis revealed that citric acid, in this situation remote from the influence of periodontal ligament and junctional epithelium, did not enhance new fibrous attachment and new cementum formation nor did it reduce artifactual tissue separation, root resorption, or ankylosis. Ankylosis and root resorption were the predominent features of the healing root surfaces facing bone and gingival tissue, respectively. However, the amount of root resorption on the gingival side was apparently less pronounced than that reported for similar studies probably because of the use of antibiotics to control infection.
Induction of cartilage and bone by dentin demineralized in citric acid
Authors: Inoue T. , Deporter D. A. , Melcher A. H.
Published: July 2006

The capacity of a roll of dentin demineralized by either 0.6N HCl, pH 1 for 3 minutes or 3 hours, or by 3M (9N) citric acid, pH 1, for 3 minutes, to induce cartilage and bone when implanted in muscle, was investigated. Serial sections of specimens were examined 7, 10, 14. 17, and 21 days after implantation, and randomly selected sections analyzed histomorphometrically. Cartilage was induced on the internal aspect of the citric acid‐demineralized dentin roll, but significantly less than that induced after demineralization with HCl. The quantity of bone deposited subsequently did not significantly exceed the amount of cartilage that preceded it in relation to any of the preparations used. The results suggest that citric acid‐demineralized dentin induces chondrogenesis and osteogenesis when implanted in muscle, but does so less effectively than does HCl‐demineralized dentin, and only within the confines of a microenvironment. It is therefore unlikely that citric acid demineralization of root surface results in induction of cementum by this mechanism.
Sampling and preliminary analysis of the extra‐ and intracellular material involved in the attachment of human oral epithelium in vitro
Authors: Salonen Jukka
Published: July 2006

To simulate the environmental relationships of the junctional epithelium of gingiva, epithelial cells (epibolus) from explants of human oral mucosa were let to grow between the connective tissue of the explant and an underlying non‐collagenous substrate (Millipore® filter) for 9 days. The epithelial cells in contact with the filter attained a basal cell‐like morphology and secreted electron dense material eventually resembling a morphological basement membrane onto the filter. Short epithelial projections and disconnected vesicular structures were seen within the filter pores. After the establishment of the epithelium‐substratum junction, the explants were detached with alkali treatment. The accumulated proteins associated with epithelial attachment were now left within the filter. The electrophoretic analysis of these extra‐ and intracellular “filter” proteins revealed about 20 distinguishable polypeptide bands. The immunoreactions of the protein blots allowed to identify 4–4 cytokeratins and laminin. No specific polypeptides were discovered with the anti‐type IV collagen antibodies. However, a minor, proline‐rich band of epithelial origin was identified in the fluorography. The described in vitro method provides a way of sampling of the components involved in the epithelial attachment for a further biochemical analysis.
In vivo antiplaque activity of a sanguinarine‐containing dentifrice: Comparison with conventional toothpastes
Authors: Schonfeld Steven E. , Farnoush Ali , Wilson Suzan G.
Published: July 2006

This study was undertaken to investigate the effect of a sanguinarine‐containing dentifrice on supragingival and subgingival plaque in response to suggestions that sanguinarine extract has antiplaque activity. Volunteer dental students were randomly assigned to a control or an experimental group. During an initial examination, plaque scores and samples of subgingival plaque were obtained. The students were given oral hygiene instructions and were told to floss once and brush twice daily, using either the experimental (sanguinarine‐containing) or control (any other) dentifrice for a period of 1 month, following which they were once more examined. Plaque scores and samples of subgingival plaque were again obtained. Examination of subgingival plaque was performed using a phase‐contrast microscope to determine the distribution of bacterial morphotypes. Comparison of the data from the initial examination with that at the completion of the study showed a significant reduction of supragingival plaque within each group. However, there was no significant difference in the amount of supragingival plaque between groups. There were no significant between‐group differences for any bacterial morpho‐type. It was concluded that sanguinarine extract had no detectable antiplaque activity when used in a dentifrice.
Quality assessment of randomized control trials in dental research I. Methods
Authors: Antczak Alexia A. , Tang Julie , Chalmers Thomas C.
Published: July 2006

The criteria and scoring method for a system to evaluate the quality of randomized control trials (RCTs) in dental research based on published reports is presented. This sytem is based on one devised for evaluation of RCTs in medicine. Items assessed in this system include randomization and blinding procedures, subject selection criteria, treatment protocols, and statistical analyses. Assessing the quality of RCTs can contribute to improved study design, implementation and reporting by investigators, and evaluation of reports by referees and editors of scientific journals.
A biochemical approach to periodontal regeneration: Tetracycline treatment conditions dentin surfaces
Authors: Wikesjö Ulf M. E. , Baker Pamela J. , Christlrsson Lars A. , Genco Robert J. , Lyall Raymond M. , Hic Susanne , Diflorio Roberta M. , Terranova Victor P.
Published: July 2006

Selective use of tetracycline HCl was studied to evaluate a potential treatment methodology. Tetracycline HCl adsorbed to dentin surfaces, binding 4.7 μg/mm2 after a 5 min exposure to a 50 mg/ml tetracycline HCl solution. Desorption in a discontinuous flow assay maintained biologically active concentrations of tetracycline HCl in the fluid phase for at least 48 h. The tetracycline HCl bound, and subsequently released from dentin retained antimicrobial activity with an ID50 of 3.7 μg/ml. Tetracycline HCl conditioning removed an amorphous surface layer, thereby exposing dentin with open tubules, as determined by scanning electron microscopy. These data suggest that tetracycline HCl‐treated root surfaces may act as a depot for release of active antibiotic, as well as serve as an improved substrate for connective tissue components vital to healing at the interface between hard and soft tissues.
Lymphokine production by human gingival lymphocytes
Authors: O'neill P.A. , Woodson D. L.
Published: July 2006

A variety of immunological mechanisms of the host have been implicated as contributing factors in the pathogenesis of human periodontal diseases. Studies using peripheral blood mononuclear cells have been equivocal; however, development of a technique for isolating lymphoid cells from human gingival tissues has allowed the investigation of local immune activities. This study was done to determine whether gingival lymphoid cells from subjects with no disease, gingivitis or periodontitis could produce lymphokines directly or in response to stimulation with plaque, Actinomyces viscosus or Bacteroides gingivalis. Results show that cells from non‐diseased gingiva produce very low levels of chemotactic factor (CF), leukocyte migration inhibition factor (LIF) or mitogenic factor (MF) directly or in response to the plaque or bacteria. Gingival cells from gingivitis tissues show low levels of lymphokine production when unstimulated, but this increases in response to plaque and A. viscosus. Cells from periodontitis tissues similarly show low to moderate lymphokine levels in unstimulated cultures but an increased production in response to plaque and B. gingivalis. These data suggest that gingival lymphoid cells may be sensitized, and become reactive in vivo in disease states, and that various periodontal disease states may be related to specific oral bacteria.
Local and systemic immunoglobulins reactive to Bacteroides gingivalis in rapidly progressive and adult periodontitis
Authors: Martin Stephen A. , Falkler William A. , Suzuici Jon B. , Hawley Charles E. , Mackler Bruce F.
Published: July 2006

The purpose of this study was to compare the reactivity of the localized immunoglobulins present in the supernatant fluids from in vitro gingival organ cultures of rapidly progressive (RP) and adult periodontitis (AP) patients with those immunoglobulins occurring systemically in the sera of these patients. Tissue excised from periodontitis patients was diagnosed and classified as being either RP or AP and placed in the wells of a multiwell microtiter plate to which RPMI 1640 tissue culture medium was added. Supernatant fluids were harvested and fresh culture medium added to the wells at 24 h intervals. Supernatant fluids and autologous sera from RP and AP patients were tested for reactivity to Bacteroides gingivalis, an organism often implicated in periodontitis, as well as B. asaccharolyticus, a non‐oral, non‐crossreacting member of the genus Bacteroides, utilizing an ELISA technique. When immunoglobulins present in gingival tissue supernatant fluids were examined, it was found that mean levels reactive to B. gingivalis were significantly greater (p < 0.05) than those to B. asaccharolyticus regardless of patient group. Similarly, the AP group always exhibited significantly (p < 0.05) increased antibody reactivity to B. gingivalis when compared to the RP periodontitis patients. However, when autologous sera from these patients were assayed, no significant differences were observed for immunoglobulin levels reactive to B. gingivalis or B. asaccharolyticus when comparing the AP and RP patient groups, or within the AP group alone. The results indicate that differences exist in the localized immunological responses of RP and AP patients to the periodontopathogen B. gingivalis that are not necessarily reflected in the systemic serum antibody responses of these patients.
A defect in fibroblasts from an unidentified syndrome with gingival hyperplasia as the predominant feature
Authors: Johnson Bradley D. , El‐Guindy Mustafa , Ammons William F. , Sampath Narayanan A. , Page Roy C.
Published: July 2006

We have studied a child with severe gingival hyperplasia, hypertrichosis, macroglossia, and abnormal facial features. Hypertrichosis was present at birth and gingival hyperplasia appeared with eruption of the primary teeth. The collagens present in the hyperplastic gingival tissue were normal in type and amount. Fibroblasts obtained from an explant of the hyperplastic tissue and maintained in culture grew at a much slower rate than a cell strain obtained from a normal young adult, but in a manner comparable to an age‐ and sex‐matched control child strain. The patient cells were abnormally fragile, they manifested an abnormal nuclear size, and they had an abnormally short life‐span in culture. They did not contain inclusions indicative of the Hurler syndrome, and chromosomal analysis failed to reveal abnormalities. The amount of protein synthesized during a test period was the same as the normal control child cells, but the amount of collagen was only about one‐half that produced by the control cells. In contrast, a cell strain obtained from an age‐related individual with phenytoin‐induced gingival hyperplasia, which is very similar clinically to the spontaneous lesion, exhibited greater rates of protein and collagen synthesis than either the normal control child strain or the patient strain. There were no significant differences among patient cells, control child cells, and phenytoin‐induced lesion cells in the pattern of protein synthesis as revealed by one‐ and two‐dimensional fluorography. Thus, fibroblasts obtained from both the spontaneously occurring and the drug‐induced gingival hyperplasia appear to be abnormal and the abnormalities persist in culture; however, the defects are not the same.
Bacteroides gingivalis activates mouse spleen cells to produce a factor that stimulates resorptive activity of osteoclasts in vitro
Authors: Bom‐van Noorloos Adri A. , Schipper Cor A. , VAN Steenbergen T. J. Marttjn , de Graaff Johannes , Burger Elisabeth H.
Published: July 2006

Oral microorganisms are generally considered to be responsible for the initiation of inflammatory periodontal disease, but the mechanism by which they cause bone resorption has not yet been established. We report here that the periodontopathic bacterium B. gingivalis activates mouse spleen cells to produce a factor that strongly stimulates osteoclast‐mediated mineral resorption. Resorption was measured as the release of 45Ca from prelabeled fetal mouse long bones in vitro.
Error variance and sensitivity associated with three different Periotron® instruments
Authors: VAN DER Bul P. , Dreyer W. P. , Kotze T. J. V. W.
Published: July 2006

Calibration curves for three different Periotron® instruments, two model HAR‐6000 and one HAR‐600, were determined using human serum. These curves revealed a quadratic relationship between the volume and Periotron® readout for all three models. The calibration curve data were subjected to an analysis of covariance to test the equality of the three slopes. These were found to be different (p < 0.00001) and pairwise comparisons of the slopes were done. The procedure showed that the differences, as measured by the different slopes of the three instruments, were statistically significant (p < 0.0001). Although there were only small differences in the response to volume ratios, and hence also in the slopes of the calibration curves of the two HAR‐6000 models, these were nevertheless significant (p ≤ 0.001). All three instruments showed good reproducibility as determined by error variances. The newer of the two HAR‐6000 models showed the best reproducibility while the other had values similar to those of the HAR‐600 instrument. It was concluded that the significantly differing response: volume ratios for the various Periotron® models necessitate the construction of calibration curves for these instruments before and during clinical studies. In addition, our data enable regular assessment of instrument reproducibility, which is an essential procedure in any long‐term project using them to measure periodontal status.
Inhibitory effects of human gingival extracts on bone resorption in vitro
Authors: Schwartz Z. , Nuki K. , Raisz L. G. , Soskolne W. A.
Published: July 2006

The effects of human gingival extracts on in vitro, bone resorption were examined and related to the amount of plaque, gingival inflammation and bone resorption present at the time of sampling. Twenty patients with varying degrees of periodontal disease were used in this study. The plaque index and bleeding index were recorded. the marginal gingiva removing surgically and immediately freeze dried. Alveolar bone resorption was then measured from the cemento enamel junction (CFI) to the alveolar bone crest directly during surgical exposure or on radiographs. The bone resorting activity of extracts from freeze dried gingiva was then tested in an in vitro bone resorption assay. No bone resorting activity was noted in 17 of the 18 extracts tested and thus no correlation could be found with the clinical indices. Mean values of the T/C ratios for 18 extracts tested indicate a biphasic suppression of control resorption by the extracts. The extracts suppressed resorption stimulated by known bone resorbing agents. H [eating of the extract prior to testing eliminated this suppressive effect. It is concluded that inhibitors of bone resorption are present in human gingival extracts. Their presence may explain our inability to demonstrate bone resorhing activity in human gingiva.
Distribution of Actinobacillus actinomycetemcomitans in localized juvenile periodontitis plaque: an electron immunocytochemical study
Authors: Berthold Peter , Listgarten Max A.
Published: July 2006

The use of an indirect electron immunocytochemical labelling procedure for labelling Actinobacillus actinomy cetemcomitans (serotype b) in ultrathin sections of pure bacterial cultures and in localized juvenile periodontitis‐derived plaque is described. Optimal labelling was obtained after fixation with 2.5% glutaraldehyde, embedding in glycol methacrylate and labelling with highly diluted absorbed rabbit anti‐A. actinomycetemcomtians γ‐globulin followed by incubation with diluted goat anti‐rabbit γ‐globulin conjugated with horseradish peroxidase. and subsequent histochemical visualization of the peroxidase. These labelling conditions were used to determine that no cross reactions existed with commonly found plaque bacteria. Two of 5 labelled plaque specimens were positive for this A. actinamycetemcomitans serotype. In one specimen large numbers of labelled bacteria were located only in the most apical portion of the plaque layer. In another specimen labelled cells were scattered throughout the plaque. Control experiments using normal rabbit γ‐globulin were all negative.
A robust digital method for film contrast correction in subtraction radiography
Authors: Ruttimann Urs E. , Webber Richard L. , Schmidt Edgar
Published: July 2006

Digital subtraction radiography requires close matching of the contrast in the films to be subtracted. A digital method is presented permitting the retrospective correction of film contrast differences. The method is nonparametric and derives the required gray level transformation directly from the histograms associated with the radiographs. This transform is shown to be unique and monotonic. It is based on fewer theoretical assumptions than a previously described parametric correction method, and it performs significantly better in reducing the contrast mismatch measured by the standard deviation of the gray levels in the subtraction image.
Role of “diseased” root cementum in healing following treatment of periodontal disease
Authors: Nyman Sture , Sarhed Gun , Ericsson Ingvar , Gottlow Jan , Karring Thorkild
Published: July 2006

This study was undertaken to examine if root debridement in the treatment of periodontal disease must include the removal of the exposed cementum in order to achieve periodontal health. Five beagle dogs were used. Periodontal tissue breakdown around the second, third and fourth mandibular premolars was accomplished by placing plaque‐collecting cotton floss ligatures around the necks of the teeth. When the destruction of the attachment apparatus after 4 months had progressed to a level corresponding to half the length of the roots, the ligatures were removed. During a subsequent period of 2 months the experimental teeth were left without ligatures but the dogs were still allowed to accumulate plaque. On day 180. the experimental teeth were subjected to (lap surgery. Following elevation of the Iiaps, the teeth on one side of the jaw were scaled and the exposed root cementum was removed using diamond burs. On the contralateral side no scaling was performed and the roots were only polished with the use of rubber cups, interdental rubber tips and a polishing paste. After irrigation of the roots with sterile saline the flaps were repositioned at their original level and sutured. Following a healing period of 2 months, during which both test and control teeth were subjected to regular plaque control, the dogs were sacrificed and the jaws placed in fixative. After decalcification. histological sections of the experimental teeth and their periodontal tissues were produced. The histometric data demonstrated that the result of healing was similar whether or not the previously exposed root cementum had been removed. In both situations a junctional epithelium with a non‐inflamed subjacent connective tissue was formed. In addition, new connective tissue attachment was frequently observed at the apical extent of the wounds following both types of treatment. The results suggest that the removal of the root cementum for the purpose of eliminating endotoxins possibly present within the cementum is not necessary for accomplishing periodontal health.
Detection of cathepsin L‐like proteinase and cathepsin D in gingival fluid
Authors: Lah Tamara , Skallrič Urošer , Babnik Joža , Turk Vito
Published: July 2006

Intracellular proteinases play an important role in normal and pathological degradative processes. The contribution of cysteine proteinases in connective tissue breakdown is known, but their activity in the inflammatory process of periodontal disease received only limited attention. Gingival fluid was collected from eight female patients with different degrees of periodontal disease as indicated by pocket depth. Proteolytic activity of cathepsins, D and L was measured using hemoglobin as substrate.

Evidence that cathepsin L‐like proteinase contributed significantly to acid proteolytic activity in gingival fluid was found. In addition, proteolytic activity at pH 3.5 and cathepsin L‐like activity in gingival fluid were positively correlated with the degree of periodontal disease as measured by the pocket depth at the site of fluid collection. Cathepsin D in crevicular fluid was also determined immunologically. These results may contribute to a better understanding of the etiopathology of periodontal disease.