bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of complement in initial gingivitis
Authors: Kahnberg K‐E. , Lindhe J. , Attström R.
Published: July 2006

The effects of decomplementation by Cobra Venom Factor (CVF) on cell migration and vascular permeability in experimentally induced initial gingival inflammation in the dog have been determined. Gingivitis was provoked in four Beagle dogs with normal gingiva during an eight hour period by topical application of an extract of human plaque. In each dog, the applications were performed on one side of the jaws before, and on the contralateral side after decomplementation. Following six and a half hours of plaque extract application, colloidal carbon was injected intravenously in one of the hind legs. At the end of the application period biopsies were sampled, the tissue sections were embedded in Epon and semi thin sections (2–3 μm) were prepared and examined in the light microscope regarding (1) amount of carbon containing vascular units subjacent to the junctional epithelium (2) number of neutrophils and mononudear leukocytes within the junctional epithelium.

The present experiment indicates that (1) plaque extract contains substances which, when applied onto the margin of normal gingiva, mediate attraction of leukocytes and alterations of the function of the dento‐gingival vasculature i.e. induce symptoms of initial gingivitis. (2) in the decotnplemented animals the plaque components displayed a) a reduced capacity to influence vascular function but b) an almost unaltered leukocyte attracting potential with regard to neutrophils.
Trauma and progression of marginal periodontitis in squirrel monkeys
Authors: Polson A. M. , Meitner S. W. , Zander H. A.
Published: July 2006

This investigation was undertaken to characterize the changes which occurred to the interproximal alveolar bone between adjacent teefh which were being moved alternately mesially and distally. Mandibular second and third bicuspids in ten squirrel monkeys were subjected to alternating periodontal stresses for 10 weeks and they became mobile during this period. Histologic examination showed an initial phase of intense resorptive activity associated with the coronal alveolar bone, and the morphology of this bone eventually consisted of a number of osseous islands surrounded by a loosely arranged, highly vascular and cellular connective tissue. Histometric comparison of this bone with that from normal specimens showed that the trauma caused a loss in crestal height and a great overall reduction in the percentage of coronal alveolar bone. There was no loss in connective tissue attachment verifying that traumatic lesions and their sequelae in the periodontal ligament do not produce periodontal pockets.
Trauma and progression of marginal periodontitis in squirrel monkeys
Authors: Polson A. M. , Meitner S. W. , Zander H. A.
Published: July 2006

Previous studies have shown that repeated trauma to the interproximal periodontium induced by jiggling of teeth resulted in alveolar bone loss and, when combined with periodontitis, increased the amount of bone loss compared with periodontitis alone. This study was designed to answer the question on the reversibility of such bone loss. Eight squirrel monkeys were divided into two equal groups. In four animals, the mandibular second and third bicuspids were jiggled mesio‐distally for ten weeks. On one side a marginal periodontitis was induced at the same time. In the other four animals the same procedures were instituted except these animals were killed ten weeks after jiggling had been stopped. Step‐serial histoiogial sections of the coronal interproximal area were analyzed. Loss in height of alveolar bone and percentage of bone occupying the coronal area were measured histometrically. When jiggling was stopped, a significant reversibility of bone loss occurred. However, no such reversal was seen in the presence of periodontitis. It was postulated that presence of an existing marginal inflammation inhibited the potential for bone regeneration.
Interbacterial aggregation of actinomyces naeslundii and dental plaque streptococci
Authors: Ellen R. P. , Balcerzak‐Raczkowski I. B.
Published: July 2006

The ability of human Actinomyces naeslundii strains to aggregate with dental plaque streptococci was found to be strain specific. A. naeslundii strains aggregated strongly more often with specific strains of Streptococcus sanguis and Streptococcus mitis than with Streptococcus mutans strains. The effects of proteolytic enzymes and heat on the interbacterial affinities of A. naeslundii 398A and S. sanguis S, two strains which were found to aggregate strongly, were studied. Enzyme or heat treatment of 398 A, but not S. sanguis S, impaired aggregation. Electron microscopic examination of aggregates of untreated bacteria revealed that the attachment between cells of strains 398 A and S was mediated by short tufts of electron‐dense fuzzy components of the cell surfaces. The affinity between cells of A. naeslundii and the streptococci which readily colonize cleaned smooth tooth surfaces may account, in part, for the previously‐reported, delayed increase in A. naeslundii proportions among bacteria forming early plaque deposits.
Leukocyte migration inhibition by bacterial antigens in patients with periodontal disease
Authors: Budtz‐Jörgensen E. , Kelstrup I. , Funder‐Nielsen T. D. , Knudsen A. M.
Published: July 2006

Cell mediated immunity to ultrasonicates of the dental plaque bacteria Bacteroides melaninogenicus, Fusobacterium nucleatum, Veillonella parvula, and Actinomyces viscosus and to PPD was studied in edentulous controls and patients with periodontal disease by means of the leukocyte migration test in agarose. In patients with gingivitis, migration inhibition was significant to V. parvula only, but correlated with the degree of plaque accumulation and gingival inflammation. In patients with moderate periodontitis the migration inhibition response was further increased and was significant with all four plaque antigens. However, in patients with severe periodontitis or juvenile periodontitis migration inhibition was not significant and was apparently suppressed. The response to PPD was of the same magnitude in controls and all four groups of patients indicating that the observed migration inhibition reactions to the dental plaque bacteria are controlled by specific factors. It is suggested that the depressed leukocyte migration inhibition response in patients with advanced periodontal destruction is due to an exhaustion of immune cells in peripheral blood.
Vascular responses in the oral mucosa following cryosurgery
Authors: Whittaker D. K.
Published: July 2006

Quantitative methods have been applied to vascular responses following cryosurgery of oral mucosa. The response is delayed and prolonged and the vessels involved are described. Stasis intervenes at a later time.
Genetic traumatic occlusion in the mouse
Authors: Miller William A.
Published: July 2006

The dramatic alveolar bone loss associated with a developmental genetic traumatic occlusion in the ‘crinkled’ mutant (cr/cr) of the house moose is described from osteological and radiographic investigations. Bone loss is severe palatally, buccally and interdentally in the upper molar teeth and lingually in the lowers. This is associated with severe and abnormal tooth wear when compared to normal mice and could also be associated with changes in the temporomandibular joint. Possible uses in periodontal research are suggested.
Predominant cultivable microbiota in periodontosis
Authors: Newman M. G. , Socransky S. S.
Published: July 2006

The predominant cultivable microbiota of periodontosis lesions was studied in 5 patients using a specially designed anaerobic sampling device and current anaerobic methodology. Two samples from the apical portion of periodontosis lesions and one sample from clinically normal sites were taken from each patient. The results indicated that samples obtained from pocket sites consisted of significantly increased proportions of Gram negative anaerobic rods when compared to a predominantly Gram positive flora in the control sites. Many of these organisms could not be classified. An additional 9 periodontosis patients were sampled and it was determined that groups of Gram negative anaerobic rods from similar to the first 5 patients were isolated. These organisms were differentiated into 5 groups based on morphologic, cultural, and biochemical characteristics.
The effect of dietary Gantrisin® supplements on the flora of periodontal pockets in four beagle dogs
Authors: Newman Michael G. , Sandler Mathew , Ormerod William , Angel Leo , Goldhaber Paul
Published: July 2006

The predominant cultivable flora from advanced periodontal pockets (> 4 mm bone loss) was compared with the microbiota isolated from areas of incipient periodontal lesions (< 2 mm bone loss) in Beagle, dogs with periodontal disease. In addition the effect of long term dietary antibiotic (sulfisoxazole) administration on the microbial flora and the clinical course of periodontal disease in these animals was determined.

Four male Beagle dogs, 40 months old, had been maintained on a soft diet for 36 months prior to the time of bacterial sampling; two of the animals had been given 44 mg/Kg Gantrisin® (sulfisoxazole) p.o. daily for 3 years. Clinical and radiographic examination of the dogs demonstrated that Gantrisin® seemed to have no effect on the development of periodontitis since both groups exhibited clinical signs of periodontal disease and demonstrated a range of alveolar bone destruction from minimal to severe.

Bacterial samples were obtained and cultured from the base of each site utilizing anaerobic techniques. In addition, direct microscopy of whole plaque was carried out.

The distribution of the predominant cultivable flora in both treated and non‐treated animals revealed that Gram positive organisms predominated in the incipient lesions, while Gram negative anaerobic rods predominated in advanced periodontal lesions. In all sites anaerobes outnumbered facultatively anaerobic bacteria by at least 2:1.
Sensitivity of dog plaque microorganisms to chlorhexidine during longitudinal studies
Authors: Briner W. W. , Wunder J. A.
Published: July 2006

Plaque microorganisms, which were either aerobic or facultative, from dogs treated 7 or 42 months thrice daily with 0·2 % chlorhexidine gluconate showed a decreased sensitivity to chlorhexidine when compared with plaque organisms from dogs treated with water. This decrease in sensitivity was not associated with a decrease in efficacy of chlorhexidine against plaque or gingivits.
A genetic and epidemiologic study of periodontal disease in Hawaii
Authors: Chung C. S. , Kau M. C. W. , Chung S. S. C. , Schendel S. A.
Published: July 2006

Using a modification of the Ramfjord procedure, 939 individuals aged 14 years or above of six racial groups were examined for periodontal disease to study the effects of genetic and epidemiologic factors with special emphasis on inbreeding and race. Other factors studied included sex, age, years of education, frequency of toothbrushing, smoking, tooth malalignment, and medical history.

Among six racial groups, two distinct clusters were discernible even when relevant concomitant variables including years of education and oral hygiene practice were adjusted for. Caucasians, Japanese, and ≪Others≫ had clearly higher levels of periodontal health status than Hawaiians or part‐Hawaiians, Samoans, and Filipinos. The difference in Samoans and Filipinos may be explained in part by cultural and socioeconomic factors associated with their recent immigration to Hawaii. Inbreeding was not related to any indicator of periodontal disease showing inconsistency with the hypothesis of significant role of recessive genes in the etiology of the disease.

Smoking was found to have adverse effect on periodontal health status, whereas no clear‐cut association was noted with tooth malalignment. The principal component analysis on eight periodontal disease variables led to the extraction of two major factors, destructive periodontal disease and plaque accumulation.
The effect of age and sex on the relationship between crevicular fluid flow and gingival inflammation in humans
Authors: Borden S. M. , Golub L. M. , Kleinberg I.
Published: July 2006

In a study on 120 subjects (60 males and 60 females) between the ages of 12 and 69 years, it was found that the relationship between gingival inflammation and crevicular fluid flow was not affected by age or sex. Because of their relationship to gingival disease, the effect of age and sex on crevicular pH, urea content, and concentration and crevice depth were also examined. Whereas, aging had no significant effect, sex may have had a slight effect since males exhibited slightly deeper pockets and a higher crevicular pH at most levels of inflammation. However, this may be due to poorer home care in males. The results have confirmed the inflammation‐crevicular fluid relationship in a large number of adults of both sexes and add support for the use of crevicular fluid flow measurements as an objective technique for monitoring gingival inflammation.
Variable antigenicity of lyophilized allogeneic and lyophilized xenogeneic skin in guinea pigs
Authors: Yukna Raymond A. , Turner Donald W. , Robinson Linda June
Published: July 2006

Intraoral use of freeze‐dried skin (EDS) allografts and xenografts has raised questions concerning host immunologic response to these transplanted tissues. Separate groups of outbred guinea pigs were sensitized with suspensions of xenogeneic (human) FDS (XFDS) or allogeneic FDS (AFDS). Intradermal challenge with saline, appropriate FDS suspension, and intact sections of the appropriate FDS was performed. Findings at 24 and 48 hours post‐challenge demonstrated positive skin reactions to the XFDS materials and an absence of any reaction to the AFDS materials. Positive (Freund's complete adjuvant) and negative (saline) controls were similarly tested and yielded expected results. In vitro findings using serological and migration inhibitory factor assays paralleled those of the skin tests. The results of this study indicate that allogeneic FDS grafts do not produce detectable host sensitivity and appear to be immunologically preferable to xenogeneic FDS grafts for intraoral use.
Regeneration of the basal lamina complex during epithelial wound healing
Authors: Sciubba James J.
Published: July 2006

The purpose of this study was to follow the time sequence of events in the reformation of the attachment complex between epithelium and lamina propria of oral mucosa following incisional wounding. An incisional wound of minimal depth was made along the dorsal surface of rat tongue. From nine groups of animals, tissue specimens were collected from 0 through 96 hours and processed routinely for electron microscopy.

The formation of the attachment complex was followed in relation to the epithelial cells migrating across the wound space. The earliest discernable changes denoting initiation of reattachment were preceded by a short period of direct contact between epithelial plasma membrane and fibrin. Attachment did not occur in epithelial cells not bordering on fibrin, suggesting that in the system studied such contact is a prerequisite for reattachment. The ultrastructural components of the attachment complex appeared in an orderly chronologic and spatial sequence, with the additional components appearing as time elapsed between the arrival of the cell in its new location and the collection of the tissue specimen.
The effect of cigarette smoke on human oral polymorphonuclear leukocytes
Authors: Kenney E. B. , Kraal J. H. , Saxe S. R. , Jones J.
Published: July 2006

A group of smokers and a group of non‐smokers were the participants in this study The groups were matched by age and gingival health. Oral polymorphonuclear leukocytes (PMN) were harvested from the subjects by saline mouth rinses. These PMN were tested for their ability to phagocytize latex spheres and to exclude trypan blue. Tests were performed for smokers and non‐smokers on three consecutive days, with identical procedures except that every participant smoked one cigarette on the second day immediately prior to cell collection, PMN harvested from the oral cavities of smokers were less vital as measured with the dye exclusion test and were less able to phagocytize particles on each experimental day. Smoking one cigarette immediately prior to cell collection resulted in a further decrease of these parameters for both smokers and non‐smokers.
Study of periodontal disease in children and young adolescents
Authors: Biswas Shibdas , Duperon D. F. , Chebib F. S.
Published: July 2006

Forty children from 4 groups (pre‐and post‐pubertal males and pre‐and post‐pubertal females) were examined in relation to periodontal disease. The following parameters were examined: i) crevice fluid volume, ii) pocket depth, iii) pH of the supragingival plaque and crevice pH, iv) collagenolytic activity of the crevice fluid, and v) urea in the crevice fluid. Each of the variables studied was subjected to a 3‐factor factorial analysis of variance. The factors considered were age (pre‐pubertal vs. post‐pubertal), sex (male vs. female) and inflammation index (0 vs. 1 vs. 2 and 3). In this study the corresponding means were compared and graphed. The results are prepared as the effects of age, sex and gingival inflammation and the various interactions. In general, the amount of fluid was higher in females than in males; the amount of fluid was greater in the post‐pubertal group than in the pre‐pubertal group. The fluid volume varied directly (P < 0.01) with increasing inflammation and this held true for both the sex and age groups. Crevice depth followed the same trend. The pH of plaque and crevice of females with healthy gingivae was lower in the post‐pubertal than in the pre‐pubertal group; males demonstrated an opposite response. In inflamed gingivae, both pH values were lower in pre‐pubertal females than in the post‐pubertal group. In post‐pubertal males, however, the response to inflammation showed an opposite trend to that of females both in the pre‐and post‐adolescent groups. The pH responses appear to be related to hormonal changes which occur during puberty. The visible collagen lysis in the crevice fluid was higher in females than in males, and appeared to increase with age. The percentage of soluble collagen increased with increasing inflammation. Crevicular fluid total urea content actually rose with inflammation, but the concentration decreased due to the increase in fluid volume.
Study of crevice fluid in relation to periodontal disease in children
Authors: Biswas Shibdas , Duperon D. F. , Chebib F. S.
Published: July 2006

Crevicular fluid from four groups of children was examined. The crevice fluid was collected at random from the anterior region of the mouth (6 distal and 6 mesial) in filter paper strips and the volume of the ascending fluid in each strip was measured by techniques previously described by Smith, Golub & Duperon (1974). Gingival condition was assessed on the basis of the Löe and Silness Index (1963). The crevice fluid was pooled on the basis of age, sex and gingival inflammation, and each pool was analyzed for protein, carbohydrate, total calcium, phosphate and nitrogen. Protein and carbohydrate were analyzed by taking an aliquot of the pooled sample directly, whereas total calcium content, phosphate and nitrogen were analyzed in a sample digested with concentrated sulfuric acid and 30 per cent (V/V) hydrogen peroxide. Standard chromogenic reagents were used in analysis. Each component was regarded as a single variable. In this study the corresponding means were compared and graphed. The results were presented as the effects of age, sex and G. I. and various interactions. The data was analyzed to determine i) the absolute quantity of each component and ii) the concentration of each (μg/μl) in the crevice fluid. The concentration of protein in the fluid was higher in females than in males and was also higher in the post‐pubertal group than in the pre‐pubertal group. The concentration of carbohydrate and calcium followed almost the same trend as that of protein. The difference in the concentration of phosphate was not significant. The levels of calcium and phosphate were several times higher than serum levels, indicating that calcium and phosphate were hyperconcentrated within the crevice overnight, as occurred with urea (Golub, Borden & Kleinberg 1971). The high protein content may be related to the high urea content of the crevice fluid from inflamed gingivae. The high urea content will give rise to a high pH‐a pH which can be favourable to the calcification process. Also, the hyperconcentration of calcium and phosphate, particularly in the post‐pubertal group, may favour this process.
Calcium deficiency, pregnancy and lactation in rats
Authors: Rasmussen P.
Published: July 2006

Adult female rats were subjected to severe calcium deprivation by feeding them a calcium‐deficient diet containing oxalate (Test group a), and in addition by subjecting some of them to pregnancy and lactation (Test group b). The mandibles were collected for determination of ash and cortical bone area.

The ash content of the mandible was reduced in both test groups, but the additional effect of pregnancy and lactation was less than that previously found in long bones. Planimetric analysis revealed that bone removal had not occurred from the periosteal surfaces of the mandible. Most of the bone loss had taken place by resorption from its endosteal surfaces.
A mathematical investigation of the biomechanical effects of simulated periodontal surgery
Authors: Knoell and A. C. , Vogan W. I.
Published: July 2006

Through the use of a three‐dimensional finite‐element model of a dried human mandible, the stress and strain fields developed in localized tooth‐loaded regions of the mandible, both before and after osseous surgery, were investigated. It is shown that simulated osseous surgery results in a significant increase In stress and strain concentration in the bone overlying periodontally involved teeth treated by osteoectomy, as compared with the natural condition. Predicted strain distributions on the buccal surface of the mandible are compared with experimental data to indicate the degree of correlation between model predictions and test results.
Lymphocyte blastogenesis to plaque antigens in human periodontal disease
Authors: Lang Niklaus P. , Smith Frederic N.
Published: July 2006

Lymphocyte transformation in response to dental plaque antigens has been used to determine the association between cellular immune responses and the periodontal status in man. An in vitro system for lymphocyte transformation was used. Triplicate microcultures of peripheral blood lymphocytes were stimulated with four different concentrations of V. alcalescens, B. melaninogenicus, F. nucleatum, A. viscosus, A. naeslundii, S. sanguis and pooled plaque of human origin. Phytohemagglutinin served as a positive and saline as negative control. The uptake of 3H‐thymidine during blastogenesis was measured by liquid scintillation counting.

Forty‐eight subjects divided into four equal groups of individuals with either normal gingivae, gingivitis, mild to moderate, or advanced periodontitis participated in the study. The subjects were all between 35 and 45 years of age. The peripheral blood lymphocytes of the normal subjects did not generally undergo blastogenesis with any of the organisms. However, when blastogenesis occured in other groups, the highest stimulation was found in the advanced periodontitis group. B. melaninogenicus stimulated blastogenesis only in the advanced group. A. viscosus and A. naeslundii stimulated lymphocytes to various degrees in all except the normal group. All the other antigens did not show any differences in stimulations between any of the groups.
Periodontally diseased cementum studied by correlated microradiography, electron probe analysis and electron microscopy
Authors: Selvig K. A. , Hals E.
Published: July 2006

Earlier studies have indicated an increased mineral content in the surface layer of cementum which has become exposed to the oral cavity as a result of gingival retraction. The purpose of this study was to characterize this process more precisely by elemental analysis. Serial ground sections of suitably embedded teeth from residents of a nonfluoridated area were microradiographed. Sections showing exposed cementum with an increased radiopacity of the surface layer were processed for electron probe analysis and electron microscopy. Characteristically, the radiopaque zone had an elevated Ca and P content (7–10 % increase), unchanged Mg, extremely high F (up to 1.9 %) and elevated S (0–100 % increase), as compared to unexposed cementum. The highest F values occurred concomitantly with the highest Ca and P. F showed a rapid drop and a leveling‐off at a varying distance from the root surface. Electron microscopy showed increased crystal size and improved crystallinity in the hypercalcified layer, while demineralized sections indicated an alteration of the organic matrix. In the absence of detectable caries, exposed cementum may develop a highly calcified surface layer, an F content higher than any other calcified tissue, as well as a subsurface condensation of organic material of exogenous origin.
Crevicular tissues as donor tissue for free gingival grafts
Authors: Stahl S. S. , Fletcher P. D. , Wyman B. S.
Published: July 2006

Free gingiva grafts were placed into six facial sites having minimal width of attached gingiva in three adult patients. The donor tissue consisted of autogenous pocket lining which was surgically excised immediately prior to graft placement. Thus, the graft contained crevicular epithelium and adjacent corium which was placed into the recipient bed with the crevicular epithelium facing the oral environment. Three months post‐operatively, all grafts appeared to have taken clinically. At this time, a slit biopsy was obtained from the graft site which included portions of the gingival margin and attached gingiva. Histologically, the graft area appeared different from attached gingiva. The epithelium showed evidence of parakeratinization. However, the cells appeared enlarged, the cellular layers less distinct and the entire epithelium was widened. The corium seemed less well organized than normally seen in attached gingiva. Since the donor tissue consisted of crevicular epithelium and adjacent corium, it would appear that the altered environment into which this tissue was placed affected its normal morphology.
The effect of scleraf grafts in osseous defects in rabbits
Authors: Beveridge B. F. , Fox E. C. , Browne R. M.
Published: July 2006

Scleral grafts were implanted into bony cavities in the tibiae of 8 rabbits for periods of two to six weeks. By four weeks, control unfilled cavities were full of woven bone, which had been remodelled into mature compact bone by six weeks. Healing of cavities filled with scleral allografts was delayed and they were not filled with woven bone until six weeks. There was no evidence of osteogenetic induction of sclera. Human heterografts caused marked rejection responses.
Influence of diphosphonates on the pyrophosphatase activity in Streptococcus mutans
Authors: Wöltgens J. H. M. , Bervoets TH. J. M. , de Vries W.
Published: July 2006

The existence and properties of an alkaline pyrophosphatase in Streptococcus mutans were determined.

The PPi‐ase activity was Mg++ dependent and strongly inhibited by EHDP, Cl2MDP and MDP concentrations higher than 10‐2 M. Complex formation with different divalent ca tions can modify the inhibiting effect of diphosphonates. The consequences of this inhibi tion for dental calculus formation are discussed.
Experimental allergic gingivitis
Authors: Sela J. , Rosenmann E. , Schechter D. , Boss J. H.
Published: July 2006

Immunized and non‐immunized rats were given 6 or 8 intragingival injections of bovine serum albumin or saline at intervals of 7, 3, 2 or 1 days. Biopsies of the gingiva were ob tained one day after the last challenge. The severity of inflammation in the oral mucosa decreased with increasing intervals between injections. Gingivitis did not develop in con trol rats, the mucosa of which was punctured 8 times without injection of solution. It is suggeseed that intragingival challenges give rise to the appearance of inhibitory factors, which are operative only when injections are administered at long spaced intervals.
Some effects of chlorhexidine acetate on the adherence of oral bacteria to dental enamel in vitro
Authors: Tustian D. G. , Ellen R. P.
Published: July 2006

The effects of chlorhexidine acetate on the ability of some oral Streptococcus and Actinomyces strains to attach to bovine enamel were evaluated in an in vitro system. The numbers of bacteria adhering per unit area to enamel blocks immersed in bacterial suspensions were enumerated using an incident light microscope. Pre‐incubation of the enamel in whole saliva to form an in vitro pellicle enhanced the adsorption of some strains and reduced the adsorption of others. Pretreatment of uncoated enamel with mouthwash concentrations of chlorhexidine significantly impaired the adsorption of two of the four test strains and enhanced the adsorption of one of the strains. Chlorhexidine pretreatment of saliva‐coated enamel enhanced the adherence of all bacterial strains tested. These changes in bacterial adsorption may reflect chlorhexidine‐mediated alterations in the properties of pellicle‐covered enamel. Pretreatment of the bacterial cells with subinhibitory doses of chlorhexidine acetate or sodium acetate did not significantly reduce the ability of the bacteria to attach to the saliva‐coated enamel surface. Together, the data suggest that the reduction in plaque accumulation associated with chlorhexidine mouthrinsing may be independent of a direct inhibition of initial bacterial adsorption to pellicle.
Streptococcus sanguis and streptococcus salivarius in early plaque formation on plastic films
Authors: Rönström Anders , Edwardsson Stig , Attström Rolf
Published: July 2006

The presence of Strep.sanguis and Strep, salivarius during early plaque formation on plastic films has been studied in humans. The numbers of other cultivable bacteria were also evaluated. In 12 adults with clinically healthy gingiva, a thin transparent plastic film was applied to the buccal surface of one of the premolars in either the upper or the lower jaw. The films were left in place for different time intervals, from 10 seconds to 240 minutes. Samples for bacteriologic analysis were taken from a defined area of each film located just coronally to the gingival margin. At each time interval, a saliva sample was also taken from each individual. The various samples, showed bacterial growth at each time interval. Immediately after salivary contamination of the films, Strep, sanguis, predominated over Strep, salivarius while in the corresponding saliva samples these proportions were reversed. During the experimental period of 240 minutes the presence of Strep. sanguis on the film increased with increasing time, while the corresponding figures for Strep, salivarius were low. The film technique used seemed to provide an adequate method for studies of early plaque formation.
Autoradiographic study of the penetration of radiolabelled dextrans and inulin through non‐keratinized oral mucosain vitro
Authors: Alfano M. C. , Chasens A. I. , Masi C. W.
Published: July 2006

Although a well known barrier effect against the penetration of macromolecules exists at the basement membrane region of epithelial tissues, recent reports suggest that the penetration of smaller molecules may also be impeded by this region. Considering the probable importance of the permeability of gingival crevicular tissues in the etiology of inflammatory periodontal disease, the present study was designed to evaluate the barrier function of the basement membrane region of non‐keratinized oral mucosal epithelium to a series of radiolabelled penetrating molecules of increasing molecular weight. Tritium labeled inulin (ℳ 5,000), dextran 20 (ℳ 20,000) and dextran 70 (ℳ 70,000) were used as penetrating molecules, and autoradiographic tracer techniques were used to evaluate the barrier function. The study was conducted in vitro to eliminate vascular “wash‐out” effects and to facilitate study of penetration across the basement membrane region in both directions. The results indicated that although the penetration of inulin and dextran 70 was impeded by the basement membrane region, the penetration of dextran 20 was not affected. Therefore, the barrier function of the basement membrane region is not solely dependent on the molecular weight of the penetration molecule. Mechanisms to account for the findings are described and the significance to periodontal disease is discussed.
A quantitative study of osteoclastic bone resorption during experimental periodontal disease in the golden hamster
Authors: Saffar Jean‐Louis , Baron Roland
Published: July 2006

The aim of this study was to measure the osteoclastic resorption of alveolar bone during an experimental periodontal disease. Twenty golden hamsters were used: 10 animals were fed a normal diet and served as controls and 10 animals were fed the Keyes hyperglucidic diet during 6 months to induce periodontal disease. The results show that the different surfaces of alveolar bone do not react in the same proportion: the number of osteoclasts is greatly and significantly increased (p < 0.001) along the periosteum, significantly increased (p < 0.01) along the endosteum, and not modified along the alveolar wall.The number of osteoclasts along the alveolar wall is negatively correlated with the number of osteoclasts along the endosteum and the periosteum.
Inflammatory changes in gingival collagen in the alloxan‐diabetic rat
Authors: Golub L. M. , Garant P. R. , Ramamurthy N. S.
Published: July 2006

Chronic inflammation was induced by repeatedly injecting ferritin‐antiferritin (AgAb) complex into gingiva of normal, untreated and insulin‐treated alloxan diabetic rats. Blood glucose levels, the urinary excretion of hydroxyproline, and the salt‐soluble, acid‐soluble and insoluble collagen levels in gingiva were measured in all groups of rats. Additionally, the gingival tissues were examined by light and electron microscopy. Injection of AgAb into the gingiva of normal rats produced typical chronic inflammatory cell infiltrates, fibroblasts containing profiles of intracellular collagen, disruption of extracellular collagen fibrils and a reduction in collagen concentration primarily affecting the insoluble fraction. The inflamed gingiva of the diabetic rats demonstrated similar changes histologically except that the macrophages were more congested with phagocytosed material and the fibroblasts appeared smaller and less well developed. Unlike the normal rats, the collagen content of the diabetic gingiva was not reduced by inflammation. This loss of the inflammatory effect on gingival collagen content during experimental diabetes was explained by three possibilities: (1) that diabetic fibroblasts had a decreased ability to effect collagen remodeling during inflammation, (11) that the inflammatory cells responsible for gingival collagen loss were less active in diabetes, and (111) that diabetic gingival collagen, because it was more highly crosslinked than normal, resisted the degradative enzymes produced in increased amounts during the inflammatory process.
Studies of the predominant cultivable microbiota of early periodontitis
Authors: Darwish S. , Hyppa T , Socransky S. S.
Published: July 2006

Plaque samples were taken from 3 comparably sized areas on the buccal surface of individual teeth of 7 patients with early periodontitis. The total counts from the area immediately coronal to the gingival margin were 10–100 times as high as counts from areas immediately apical to the gingival margin or at the base of the pocket.

The microbial composition of the predominant cultivable microbiota in cach of the 3 sites on the teeth of 4 of the patients was studied using comprehensive cultural techniques. The sample were anaerobically dispersed, anaerobically serially diluted and plated in 5 environments. The isolates were extensively characterized and where possible identified to genus or species. The composition of the microbiota differed from subject to subject although the clinical conditions were seemingly similar. The two subjects who had been scaled two weeks prior to sample taking showed relativwely minor differences between the supragingival and subgingival samples. The predominant organisms detected were mainly S. sanguis, A. viscosus, and “suspected pairs”, in contrast the two subjects who had no scaling showed a remarkable difference between the supragingival and subgingival microbial flora. The subgingival flora consisted mainly of anaerobic microorganisms, with peptostreptococci predominating in one subject and B. melaninogenicus and A. israelii predominating in the other subject.
The cellular response to topically applied horseradish peroxidase in the gingiva of normal and immunized dogs
Authors: Kahnberg K.‐E. , Morgan P. , Lindhe J.
Published: July 2006

In the present study efforts were made to demonstrate the penetration of topically applied horseadish peroxidase (HRP) through the junctional epithelium of dogs and to study the cellular reactions in normal and sensitized dogs.

Three beagle dogs were used. HRP dissolved in saline (5 mg/ml) was topically applied to two jaw quadrants of normal dogs and biopsies obtained after 8 hours. The dogs were then sensitized to HRP > Similar topical applications were carried out in the remaining quadrants and further biopsies taken. The gingival specimens from two dogs were analyzed histometrically with regard to the numerical and volumetric density of inflammatory cells in the junctional epithelium (JE) and subjunctional connective tissue.

The histologic and ultrastructural examination showed that topical application of HRP to the gingiva of normal dogs stimulated the accumulation of inflammatory cells in the JE, In sensitized dogs similar HRP application resulted in a six‐fold increase in neutrophils and a two‐fold increase in mononuclear leukocytes. The sensitized dogs also developed and increased volumetric density of inflammatory cells and blood vessels in th subjunctional connective tissue. There was ultrastructural evidence of enhanced phagocytic activity by macrophages accompanied by marked neutrophil degranulation.
A clinical study of gingivitis of deciduous and succadaneous permanent teeth in dogs.
Authors: Hock Janet
Published: July 2006

The objective of this study was to determine the severity of gingivitis of newly erupted permanent teeth of dogs which had exhibited plaque and gingivitis around the predecessor deciduous teeth. Two litters of 4 and 6 mongrel dogs were assessed clinically using G. I. and P1.I. (Löe 1967) and tests for crevicular exudate. Selected premolar gingiva were biopsied and processed for light microscopy. A plaque inducing diet was fed to 2 dogs in each litter. Control dogs were fed a hard diet and subjected to regular plaque removal procedures, using daily toothbrushing and 0.2% chlorhexidine application. Clinical examinations on canines and premolars were made at weekly intervals from the 16th to the 30th week of age.

Results showed that in control dogs, teeth from which plaque was removed regularly exhibited non‐inflamed gingiva throughout the study. Gingivitis in experimental dogs was relaed to the continued presence of plaque. In these dogs, the mean G.I. and P1.I. scores of permanent teeth were significantly higher (p < 0.001) than those of the predecessor deciduous teeth which had exhibited plaque and pingivitis.
The development of a maximal clenching force between two antagonistic teeth
Authors: van Steenberghe D. , de Vries J. H.
Published: July 2006

The development and reproducibility of maximal clenching forces developed between two antagonistic teeth on a gnathodyamometer were examined. All the occlusal surface of the two teeth was used by adapting acrylic bite blocks on the dynamometer. It appeared that the maximal clenching force is a reproducible value. Itwas also noted that the developed force increases progressively when a maximal clenching effort is exerted successively every fiften seconds, even after a pause of five minutes. After about ten clenching efforts the developed force became stabilized. However, when the subject paused for ten minutes, the clenching force he developed immediately afterwards, returned to the level at the beginning of the experiment.
Immunofluorescent localization of soluble dental plaque components in human gingiva affected by periodontitis
Authors: Ranney Richard R.
Published: July 2006

In order to determine if soluble plaque antigens are found in the gingiva in the course of periodontal disease, plaque was collected from 16 subjects with periodontitis, an extarct of the plaque was prepared, and antisera to the extarct were induced in rabbits; the sera were conjugated with fluorescein isothiocyanate and used in direct immunofluorescent staining of gingival biopsies from the same subjects. Fluorescent staining suggestive of soluble plaque substances were found in all biopsies, most commonly intracellularly in mononuclear cells of the connective tissue. The most common locations of the cells were subjacent to sulcular epithelium, deeper in the connective tissue in chronic inflammatory infiltrates or near vessels, or close to the oral epithelium. Occasionally a fluorescent cell could be seen within a vessel lumen. These localizations possibly represent engulfed materials within macrophages. Other morphologic appearances of fluorescence were seen that might represent immune complexes. The number of fluorescent sites varied among the subjects and seem to be related to the degree of clinical inflammation. Similar results were found using biopsies from subjects who did not contribute plaque for preparing antisera, indicating that the plaque constituents were not specific to an individual.
IgG subclasses in human periodontal disease
Authors: Mackler Bruce F. , Waldrop Thomas C. , Schur Peter , Robertson Paul B. , Levy Barnet M.
Published: July 2006

Lymphocytes with surface IgG and plasma cells producing IgG have been shown to be a prominent feature of different inflammatory periodontal lesions. The subclass nature of the IgG‐bearing cells in gingival biopsies was investigated in order to further define these inflammatory cell infiltrates and correlate them with different stages of human periodontal disease.

Mild gingivitis was characterized by lymphocytes which lacked surface IgG and Fc receptors suggestive of thymus (T) dependent cells. In severe gingivitis, the nature of the localized cellular infiltrate changed with increasing numbers of IgG1 (22%) and IgG3 (17%) labelled lymphocytes, with lesser number of IgG4 (7%) and IgG2 (1%) similar incidence of IgG subclass plasma cells was also observed. Destructive periodontitis was characterized by high numbers of plasma cells (57%) distributed throughout the gingiva. The incidence of IgG subclasses was 25% IgG1, 19% IgG4, 18% IgG3, and 1% IgG2. This distribution of IgG subclass. These findings present further evidence that the cellular infiltrate in the most destructive stage of periodontal disease, priodontitis, is primarily composed of bone marrow (B) derived cells.
The effect of age on the cellular immune response to dento‐gingival plaque extract
Authors: Church Hilary , Dolby A. E.
Published: July 2006

The Relationship between the cellular immune response to dento‐gingival plaque extract and age was exmined in 28 individuals (age range 21−47 for 27 subjects, one subject aged 64). There was a decrease, with age, in the response in a sub‐group of individuals with a severity of disease ranging from PI 4.1−7.3. There was also a correlation between the degree of disease (range PI 0.4−7.3) and the product of the numerical indicator of the response and the age of the 28 individuals studied. the significance of these findings in relation to the history of the disease is discussed.
Studies in plaque pathogenicity
Authors: Fine D. H. , Tabak L. , Salkind A. , Oshrain H.
Published: July 2006

The purpose of this study was to define a technique for the positive identification of endotoxin in heterogenous dental plaque samples. An extraction technique, which includesan acotone wash and trichloroacetic acid precipitation followed by pphenol‐water extraction was developed to reduce the level of both proteins and nucleic acids in individual plaque samples. Ten subgingival samples of adherent and loosely adherent treated in this manner retained limulus lysate almost exclusively in the phenol phase; ten supragingival samples retained activity in the phenol and water phases. further treatment of all of these samples with ribonuclease A and T1 and with lysozyme did not alter assay results, suggesting that the limulus lysate activity detected was due to Gram‐negative Bacterial cell wall fractions. this technique may be useful in determining endotoxin activity in plaque samples and ultimately, in evaluation the effectiveness of chemotherapeutic agents in reduction of plaque endotoxin.
Collagen turnover in the periodontal ligament under normal and altered functional forces
Authors: Rippin J. W.
Published: July 2006

48 six month old rats were given 1 μCi/g of body weight of tritiated proline by intraperitoneal injection, 24 of them having had the left maxillary molars extracted two weeks earlier; 4 animals from each group were killed after a further 12 hours, 1, 4, 7, 12 or 20 days. Analyses of autoradiographic grain densities in various areas of the lower first molar periodontal ligament allowed calculation of half‐lives which were attributable to collagen turnover; all such values were less than 12 days.

It is argued that the results are applicable to man in relative terms and thus have several important clinical implications. It becomes entirely feasible that the tissue destruction in chronic periodontitis is, at least in part, a function of decreased collagen formation brought about by any inflammatory process. The normal relatively slow rate of turnover in crestal fibres may well provide a barrier to the spread of inflammation from the gingiva, but its increase consequent on incresed tooth movement, as occurs in active orthodontic treatement, may reduce the barrier's effectiveness. However, the turnover rate is such taht even in adults it should not be a limiting factor in orthodontic treatement or in periodontal treatment aimed at restorring attachement.
Effects of citric acid on diseased root surfaces
Authors: Garrett John S. , Crigger Max , Egelberg Jan
Published: July 2006

The effect of topically applied citric acid on periodontally diseased root surfaces was evaluated using the scanning (SEM) and transmission (TEM) electron microscopes. Results with the SEM indicate that acid application had no effect on specimens that had not been root planed. After application to root planed surfaces, however, the acid priduced a fiber‐like surface with frequent depressions. TEM observations showed that the acid application produced a four micron wide demineralized zone, which was characterized by exposed collagen fibrils. These fibrils seemed to be continuous between the mineralized and demineralized zones of the root.

It appears that the relative success of the citric acid application in periodontal reattachment procedures is realted to the fact that the acid causes exposure of collagen fibrils in the dentin matrix, thus providing a suitable nidus for splicing with new fibrils during the healing process.