bluuebunny/crossref_metadata_2025 huggingface dataset:
Inflammatory cells extracted from chronically inflamed gingiva
Authors: Sinden P. R. V. , Walker D. M.
Published: July 2006

A method is described for separating and identifying a viable fraction of the cellular infiltrate released from specimens of inflamed gingiva by enzyme digestion. Gingiva was surgically removed from 6 patients undergoing treatment for periodontal disease. Cells released into suspension after 30, 60 and 90 minutes' incubatio with collagenase and hyaluronidase were analysed. The T lymphocyte population in the cell suspension was assayed by rosette formation with sheep erythrocytes (E) treated with S‐2 Amino ethylisothiouronium bromide (E‐AET). Complement receptor bearing cells (B lymphocytes and macrophages) were enumerated by rosette formation with sheep erythrocytes sensitized with IgM antibody (A) and complement (EAC). Macrophages were identified histochemically by their non‐specific esterase content. The average total yield of nucleated cells extracted was approximately 1X106 per 100 mg. of gingiva. The number of contaminating erythrocytes was highest at 30 minutes. At 60 minutes' incubation there was an increase in the number of contaminating epithelial cells released into suspension. The viability of extracte cells consistently exceeded 90% in the 30 and 60 minute fractions as measured by dye exclusion but fell to between 80 and 85% after 90 minutes. The proportions of T lymphocytes found in each fraction were 81%, 72% and 64% respectively. Most of the complement receptor bearing cells were found to be macrophages, and only small numbers of B lymphocytes were identified.
The migration of 111Indium‐labelled polymorphonuclear leucocytes into the oral cavity in the rhesus monkey
Authors: Scully Crisplan , Challacombe S.J.
Published: July 2006

The rout of migration of ploymorphonuclear leucocytes (PMNL) from blood to the oral cavity was examined in rhesus monkeys. PMNL were isolated from the peripheral bolld of eleven rhesus monkeysby dextran sedimentation, radiolabelled with 111Indium and administered intravenously. Sequential samples of crevicular fluid washing (CFfW), mixed and parotid saliva and mucosal washing were taken after injection of the labelled PMNL and harvested on glass fibre discs. Highest numbers of labelled PMNL weren detrected in CFW. Cell‐associated radioactivity was detedfcted in CFW within 20 min of injection of labelled PMNL and reached a maximal level 1 hour after injection. PMNL were found in CFW from mondeys with clinically normal gingiva but the number of labelled PMNL in CFW increasedm with increasing gingival index. Significant numbers of PMNL migrated into mixed saliva within 30 min, and low numbers of PMNL were detedcted in mucosal washings and in parotid saliva after 30 Min. The results indicate that the migration time of the PMNL from blood to the oral cavity is less than 30 min, irespective of the gingival index, that the gingival crevice is the main route of entry of PMNL to the oral cavity and that the numbers of PMNL migrating to the crevice increase as the gingival index rises.
Adhesive properties of periodontal dressings‐an in vitro study
Authors: Haugen Ellen , Espevik Svein , Mjör Ivar A.
Published: July 2006

The adhesive properties of three periodontal dressing materials to hard and soft tissues were studied in vitro. The results indicated that adhesion occurred between the tissues and two of the materials. The third material did not adhere to any of the surfaces tested. Only small adhesive forces were recorded, but they may be of importance in establishing a tight seal between the dressings and the tissues.
Alveolar crest height and alveolar bone density in experimental osteopenia
Authors: Ericsson Y.
Published: July 2006

General and alveolar osteopenia was provoked in young rats by Ca and /or deficiency. The alveolar bone density was assessed histometricall, the alveolar crest height between lower molars 1and 2 histometrically and/or radiographically. During the periods of the experiments no change fo the alveolar crest height was induced by the osteopenia. This fact is discussed against the background fo microscopic observations and previous reports.
The natural history of periodontal disease in man
Authors: ÅNerud ÅGe , Löe Harald , Boysen Hans , Smith Martyn
Published: July 2006

This report (the 4th in a series) waas derived from a longitudinal study of the development and progress of periodontla disease and resultant tooth loss. The first population group was established in Oslo, Norway in 1969 and Consisited of 565 male, nono‐dental students and academicians between 17 and 30+ years. A second group was establishe in Sri Lanka in 1970 and consisted of 480 male tea laborers between 15 and 30+ years. Both populations were examined 4 times and the time span between the first and fourth examinations was in Oslo 6 years ad 3 months, In Sri Lanka 7 years and 6 months. Each participant was scored for various disease parameters including the Plaque and Gingival Indices systems. The results show that for the 17 year old Norwegian the overall gingival state was good to excellent and comparable to that reported for Scandinavian dental students. There was no increase in prevalence and severity of gingival from the late teens to approximately 40 years of age. The 17 year old Sri Lankan's gingival health was considerably poorer, and a slight increase i GI levels occurred toward teh age of 40 years. In Norwegians, approximately 60–70 percent of all tooth surfaces did not have visible plaque and oral hygiene continued to improve towards 40 years of age. In the Sri Lankans, clinically recognized plaque regularly covered almost all tooth surfaces at 15 years old and no significant change occurred before 40 years of age.
The nuclear fibrous lamina of alveolar bone cells
Authors: Rifkin Barry R. , Heijl Lars
Published: July 2006

The nuclear fibrous lamina, a structure of unknown composition and function, is described in alveolar bone cells of squirrel monkeys. Osteoblasts, osteocytes, and osteoprogenitor cells contain nuclear envelopes with prominent fibrous laminas measuring up to 800° A. in width, while osteoclasts have nuclei with poorly developed laminas. The fibrous lamina is an amorphous or fine‐textures, moderaly electron dense layer directly applied on its external surface to the inner nuclear membrane. Its interior surface is bordered by beads of heterochromatin. At nuclear pore sites the lamina is either absent or markedly attenuated.
Chemotactic activity in periodontal disease
Authors: Okada H. , Silverman M. S.
Published: July 2006

Extracts of gingival tissue from periodontal patients can generate chemotactic factors from guinea pig serum for mononuclear leukocytes. Both the classical and alternative pathways of complement activation are triggered. The data do not preclude the fact that other components of the gingival extract (bacterial and/or tissue enzymes, immune complexes and endotoxin) may also play a role in the generation of chemotactic factors from complement.
The oral leukocyte migration rate index as a method of assessing periodontal disease in an individual
Authors: Hase M. P. , Reade P. C.
Published: July 2006

Functional polymorphonuclear leukocytes can be readily collected in samples of salvia. These leukocytes migrate mainly through the oral mucosa, and in particular the gingival mucosa. They are siad to migrate into the mouth at a rate characteristic of the extens of inflammation in that mouth ‐ the Oral Leukocyte migratory Rate (OMR). The Oral Leukocyte Migratory Rate Index (OMRI) has been suggested as a reproducible index of the periodontal health and should allow an objective assessment of periodontal health. The results of this investigation in which thirteen patients with varying degrees of periodontal disease were studied demonstrated consederable difficulties in obtaining reproduciblem results with all subjects and indicated that the OMRI values obtained were not directly related to improvement in periodontal health. The usefulness of OMRI as a dental health index of an individual was questioned.
The effect of diphenylhydantoin sodium on acid mucoplysaccharide and collagen contents of cotton pellet granulomas in rats
Authors: Hiramatsu M. , Hatakeyama K. , Abe I. , Minami N.
Published: July 2006

The effect of diphenylhydantoin sodium (DPH) on acid mucopolysaccharide (AMPS) and collagen contents of granuloma tissue was studied in tats. Granulomas were induced by implanting cotton pellets in the back of rats. DPH in doses of 50 and 150 mg‐kg was administered intraperitoneally from the first day after the implantation for 20 consecutive days. DPH at a dose t 150 mg/kg significantly increased the AMPS sontent on days 14 and 21 after the implantation. DPH at dose of 150 mg/kg also significantly increased the collagen contest on days, 3, 7, and 14 after the implantation.
The lymphoproliferative response during human experimental gingivitis
Authors: Patters Mark R. , Sedransk Nell , Genco Robert J.
Published: July 2006

The lymphocyte blastogenic responses to antigen preparations of bacteria from dental microbial plaque and to other non‐oral stimulants were longitudinally assayed in eitht adult subjects using the experimental gingivitis model. During the 28 days of the experimental period, these subjects abstained from all oral hygiene procedures which let to accumulatio of increased amounts of microbial dental plaque and subsequent gingivitis. In general, all subjects demonstrated a significant increase in the lymphoproliferative response to all doses of phytohemagglutinin (PHA) during the experimental period. The subjects were divided into 2 groups based on rate of plaque accumulation. Slow plaque formers exhibited a gradual linear increase in blastogenic response to bacterial antigen preparations throughout the experimental period. In the group characterixed by rapid accumulation of plaque, a marked early increase in blastogenic responses to antigens of Actinomyces viscosus, Actinomyces naeslundii, Bacteroides melaninogenicus, and Treponema denticola was observed. These same subjects, however, demonstrated a reduction in lymphocyte response to the above antigens during the later phase of the experimental period, when gingivitis was most severe. This decrease, in light of the similtaneous increase in PHA response, suggests the existence of a homeostatic mechanism to control the immune response during episodes of increased antigen load.
Studies of host responses during experimental gingivitis in humans
Authors: Baehni P. , Tsai C.‐C. , Norman M. , Stoller N. , McArthur W. P. , Taichman N. S.
Published: July 2006

The aim of the study was to find out whether autologous supragingival plaques collected at various times during the development of experimental gingivitis in men differ in their potential to induce PMN responses in vitro. Ten subjects refrained from all oral hygiene for a period of 21 days. At day 0, Day 3 and Day 21 after cressation of oral hygiene clinical indices (plaque index, gingival index, gingival crevicular fluid flow) were assessed plaque was collected at day 3 and Day 21 after cessation of Oral hygiene clinical indices (plaque index, gingival index, gingival crevicular fluid flow) were assessed plaque was collected at Day 3 and Day 21. PMNs, isolated from peripheral blood 1–2 months after the non‐brushing period were incubated with the various autologous plaques in the presence or the absence of autologous serum. Supernatants of cell cultures were monitored for extracellular release of lysosomal constituents, viz. lysozyme, myeloperoxidase and lactoferrin. There was no difference in the amounts of lysozyme, myeloperox dase and lactoferrin. There was no difference in the amounts of lysozyme or myeloperoxidase released by PMNs. The inclusion of fresh serum enhanced PMN release reactions but there was no significant differences in the relative capacity of Day 0, Day3 and Day 21 sera to modulate PMN responses. A statistically significant positive correlation was established betwen the magnitude of lactoferrin release from PMNs exposed to Day 3 plaque and the gingival fluid flow recorded on Day3. Lactoferrin is segregated in the specific granules of the PMNs which also contain other cationic proteins, collagenases and neutral proteinases. These data suggest that a possible causal relationship may exit between the release of PMN constituents and the development of inflammation during the early phases of gingivitis.
Histopathogenesis of spontaneous periodontal disease in conventional rats
Authors: Garant P.R. , Cho M.I.
Published: July 2006

The development of gingivitis and periodontitis lesions in rats fed a normal laboratory chow diet was compared to that which occurred in rats fed a high sucrose diet (Keyes'diet 2000). Histometric analysis of mesio‐distal sections through the 1st maxillary interdetal area revealed that the area of inflamed connectve tissue(ICT) increased more rapidly in the diet 2000 group. A greater incidence of periodontitis lesions with active bone resorption was noted in the diet 2000 group. Analysis of cell types in the ICT revealed no statistically significant differences between the two diet groups. However when the percent age of various cell types present in the periodontitis lesions of both dietary groups were compared to the percentage of the cell typed present in the periodontitis lesions of both dietary groups were compared to the percentage of the cell typed persent in gingivitis lesions a statistically significant increase in both large mononuclear cells was found to exist in the ICT of the Periodontitis lisions. A statistically significant decrease in the number of endothelial cells was also observed in periodontitis lesions. At the ultrastructural level cytopathologic alterations of fibroblasts and decreased collagen fibers were noted beneath the gingival epithelium. Denudation of the cemental surface beneath the epithelial attachment became progressively more severe and preceded the migration of the epithelium along the cemental surface.
Histopathogenesis of spontaneous periodontal disease in conventional rats
Authors: Garant P.R. , Cho M.I.
Published: July 2006

Spontaneously developing gingiitis lesions in the interdental tissue of rats fed a regular pelleted chow and apowdered high sucrose diet were examined in the electron microscope. The subepithelial inlamed connective tissues demonstrated a loss of collagen fibers concomittant with the infiltration of neutrophils, macrophages and lymphocytes. Fibroblasts adjacent to the inflamed gingival epithelium demonstrated cytopathic changes such as dilation of the granular endoplasmic reticulum and diminution of the Golgi complex. Endothelial cells and pericytes were characterized by prominent Gogi apparatuses, numberous mitochondria and well developed granular endoplasmic reticulum. Cytoplasmic processes of both cell types penetrated the vascular basa lamina. Apical migration of the juntional epthelium was preceeded by denudation of the cemental surface by breakdown of the connective tissue attachment.

These changes reflect subepithelial tissue breakdwon and a vascular and epithelial micgratory response, probably involving increased synthetic activities.
Preliminary observations on the inhibitory effect of tetracycline on alveolar bone loss in beagle dogs
Authors: Williams R. C. , Sandler M.B. , Aschaffenburg P.H. , Goldharber P.
Published: July 2006

Alveolar bone loss of selected periodontally diseased teeth in four beagles receiving daily tetracycline per os. was compared to three untreated beagle dogs. The percentage and rate of bone loss was measured radiographically over a 47 month period. This included a preliminary period of 20 months when no animals received antibiotics, and 27 months in which 4 animals were each given 250 mg tetracycline hydrochloride daily. During the preliminary period, all dogs progressively lost alveolar bone. However, with the institution of tetracycline treatment further loss of alveolar bone in the treated animals was arrested or markedly diminished for various intervals of time before resuming the original more accel;erated rate of bone loss. Bone loss in one animal was arrested for 27 moknths, whereas in another dog, the period of arrested bone loss was only 5 monghs. In two animals, bone loss was arrested for 17 months.

Bacterial samples from one periodontal pocket in each dog revealed that a Gram negative flora predominated in all animals. Tetracycline administration altered the pocket flora slightly with a shift to more gram positive organisms in the treated animals.

The data suggest that daily tetracycline administered orally may be effective in slowing the progressive loss of alveolar bone in beagle dogs.
Effect of sampling on the composition of the human subgingival microbial flora
Authors: Mousquéegs Thierry , Listgarten Max A. , Stoller Norman H.
Published: July 2006

Eighteen adults with chronic periodontitis participated in an experiment to study the effect of sampling the subgingival microbial flora of periodontal pockets on the subsequent microbial composition of the pocket contents. Samples of bacteria were collected atraumatically with a periodontal curette from periodontal pockets. The sample was suspended in 0.85 N saline containing 1 % gelatin. A drop of the suspension suitably diluted was applied to a microscopic slide and the specimen immediately examined by darkfield microscopy. The microbial flora was classified into coccoid cells, motile cells, spirochetes and “other” microorganisms. The proportion of bacteria in each of these 4 categories was expressed as a percentage, based on the examination of the first 200 bacteria detected in a series of high power fields (mag. × 1200). The microbial composition of the contents of each of 6 pockets was examined at day 0 (baseline data) and each pocket reexamined once either 3, 7, 14, 21, 28 or 42 days later. In addition to the microbial examination, GI and P1I scores and probing depth measurements were also obtained at day 0 and at the reexamination.

The results indicated a tendency toward reduced P1I and GI scores at the various reexaminations in comparison to baseline scores. Probing depth measurements did not change significantly. A slight but significant proportional increase in coccoid cells was detectable at 3 days and persisted at more or less the same level for the remainder of the experiment. Spirochetes showed a proportional decrease from baseline during the first week, while motile cells were proportionally reduced only on day 3. No significant changes occurred in the “other” microorganisms. It is not clear from the results if the alterations in the microbial flora were due to the sampling procedure per se or to a change in oral hygiene habits in a population of new patients suddenly more aware of their periodontal status. The clear‐cut changes from baseline to day 3 levels and the subsequent lack of change from the 3‐day through the 42‐day intervals suggest that sampling per se may have contributed only to the changes from baseline noted in the first few days. The change in oral hygiene habits, however, may have contributed not only to the initial changes from baseline, but also to the maintenance of the new microbial proportions at a stable level for the remainder of the experimental period. Despite changes from baseline, all criteria remained well within the range of values that might be expected at periodontally diseased sites in patients with untreated chronic periodontitis.
Effect of scaling and root planing on the composition of the human subgingival microbial flora
Authors: Mousquéegs Thierry , Listgarten Max A. , Phillips Russell W.
Published: July 2006

The effect of a single session of scaling and root planing on the subgingival periodontal flora of 14 adult human subjects was investigated by darkfield microscopy. At baseline, one randomly selected periodontally diseased site in each subject was assessed for GI and P1I scores, probing depth and the percentage distribution in subgingival debris of coccoid cells, spirochetes, motile cells and other microorganisms. Following a single full mouth scaling and root planing session, these criteria were reevaluated at other initially diseased sites, one per subject and time interval. The intervals tested were days 3, 7, 14, 21, 28, 35, 42, 49, 56, 70 and 90.

The P1I and GI scores tended to decrease during the first 14 days, returning to baseline around days 21–28. After another transient decline around 35–42 days the values stabilized around baseline levels till the end of the experiment. Probing depth decreased below baseline during the first 7 days and with the exception of day 28, remained below baseline level till the end of the experiment. Coccoid cells increased from 25.1 % at baseline to 76.1 % on day 3. Return to the baseline level occurred by day 21. Spirochetes did not return to baseline until day 42. The percentage of motile cells decreased significantly from baseline on day 3 only (14.8 % to 3.8 %).

The results indicated that a single session of scaling and root planing is capable of disturbing the proportions of certain bacterial forms in the subgingival periodontal flora, and that it may require approximately 42 days for the proportions to return to baseline levels. Probing depth was significantly decreased by the debridement throughout most of the 90‐day experimental period. The proportion of coccoid cells was negatively correlated with both GI and P1I scores, while the percentage of spirochetes was positively correlated with GI and P1I scores as well as probing depth measurements.
Sulcular polymorphonuclear leucocytes and gingival exudate during experimental gingivitis in man
Authors: Kowashi Yusuke , Jaccard Françlois , Cimasoni Giorgio
Published: July 2006

The number of polymorphonuclear leucocytes (PMNs) in the products of gingival washing and the rate of gingival fluid flow were measured in eight volunteers during a period of experimental gingivitis on the upper dental arch. Both parameters increased significantly during the 21 days of no brushing. However, the concentration of PMNs increased, between day 0 and day 21, by a factor of 2.1, whereas the flow of gingival fluid collected on teeth no 13 and 21 showed a 5.4 fold increase during the same period. When the amount of gingival fluid was very low (at days 0 and 28), the number of migrating PMNs was still rather high. For each volunteer, the concentration of PMNs in the washings through the period of experimental gingivitis was not always correlated to the rate of gingival fluid flow. These data confirm previous findings on dogs that sulcular PMNs emigration and flow of gingival fluid could be two independent phenomena.
Histopathogenesis of spontaneous periodontal disease in conventional rats
Authors: Garant P. R. , Cho M. I.
Published: July 2006

Spontaneously developing periodontitis lesions in rats fed a regular pelleted chow and a powdered high sucrose diet were examined by electron microscopy. Inflamed connective tissue contained numerous monocytes and large and small lymphocytes. Most large lymphocytes possessed the cytoplasmic features of blast‐type cells. Fibroblasts located within the inflamed connective tissue were found to be closely juxtaposed to mononuclear cells, many clearly belonging to the lymphocyte line. A narrow intercellular space separated adjacent cells in these fibroblast‐lymphocyte aggregates. Although the fibroblasts did not demonstrate the characteristic features usually attributed to cytotoxic damage, they did contain an increased number of dense and pleomorphic granules which contained poorly polymerized collagenous material. These features resemble, in part, those seen in colchicinetreated fibroblast suggesting that collagen secretion may be impaired in fibroblasts closely juxtaposed to lymphocytes in inflamed periodontal connective tissue.
Studies on the binding of lipoteichoic acid to osseous tissue
Authors: O'Grady R. L. , Harrop P. J. , Knox K. W. , Wicken A. J.
Published: July 2006

Tritium‐labelled lipoteichoic acid (3H‐LTA) was examined for its interaction with connective tissue components by employing autoradiography. Evidence was obtained for LTA binding to both the calcified matrix and to cells of neonatal rat parietal and long bones in vitro. The interaction of LTA with bone‐derived cells was studied in a model system utilizing an osteosarcoma cell line in tissue culture. These tumour cells incorporated 3H‐LTA as long as they were actively dividing but deacylated LTA was not incorporated. This suggested that the lipid portion of the molecule was necessary for interaction with the cells. Evidence has also been obtained for an interaction of LTA with components from the culture fluid of osteosarcoma cells.
Sonicated and passively dispersed hydrogen peroxide in periodontitis
Authors: Saroff S. A. , Alfano M. C. , Chasens A. I. , Ewen S. J. , King W.
Published: July 2006

The purpose of this study was to determine the effect of hydrogen peroxide delivered into periodontal pockets on gingival fluid flow and myeloperoxidase activity in the gingival fluid. Twenty systemically healthy human subjects presenting with moderate to advanced periodontitis were utilized. One side of the maxilla served as the control and the contralateral segment served as the experimental side. Measurements were made 0.5, 24, and 168 hours postoperatively. The experimental side was treated with 0.03 % hydrogen peroxide and the control side received distilled water. Five milliliters of fluid was delivered into the periodontal pockets either by sonication or passive dispersion. The 30 minute results indicated a mean increase in gingival fluid myeloperoxidase of 8.08 units per milliliter (U/ml) for the sonicated hydrogen peroxide, 2.05 U/ml for the passively dispersed hydrogen peroxide, 1.31 U/ml for the sonicated distilled water, and 0.60 U/ml for the passively dispersed distilled water. The values for hydrogen peroxide both sonicated and passively dispersed were significantly greater than baseline readings (p < 0.01), and the sonicated value was significantly larger than the passively dispersed value.
A microbiological study of dental calculus
Authors: Sidaway D. A.
Published: July 2006

Cultures of microorganisms isolated from human calculus have been calcified using a simple in vitro system. All strains had previously produced hydroxyapatite (HAp) under similar experimental conditions.

Ultra‐thin sections of specimens embedded in Epon 812 were examined, with a Philips 200 electron microscope, unstained or double‐stained with uranyl acetate and lead citrate.

Intracellular crystals of HAp were seen in all strains examined. The majority of Grampositive rods produced only intracellular calcification, usually mesosome associated and extracellular vesicles were rarely seen. In contrast Gram‐negative rods produced extracellular material—vesicles and debris from disrupted cells—which was heavily mineralized. The association of initial intracellular calcification with mesosomes was not always observed.

Extracellular calcification was also a feature of some Gram‐positive and all Gram‐negative cocci with cell‐associated deposits apparently originating from the cell wall. A feature of some species, particularly the Gram‐negative cocci, was the presence of randomly arranged spherules of amorphous calcium phosphate within the cytoplasm some of which appeared to be partially converted to HAp. In the majority of microorganisms examined early mineralization was apparently crystalline.

It is suggested that extracellular mineralization of Gram‐negative microorganisms may be a significant factor in early matrix calcification in natural calculus.
Transmission and scanning electron microscope studies on the surface coat of the oral mucosa in the rat
Authors: McMillan M. D.
Published: July 2006

Following treatment with either Ruthenium red or Alcian blue, the exposed surface of oral mucosa from the rat was examined in either the scanning or transmission electron microscope. The oral surfaces of half the specimens were vigorously washed prior to treatment with Ruthenium red or Alcian blue. The appearance of all scanning electron microscope specimens was compatible with that seen in the transmission electron microscope. All the washed Ruthenium red and Alcian blue and the unwashed Ruthenium red specimens had a continuous layer of granular material over the oral surface of the epithelial cells. A thick precipitate of saliva covered the unwashed Alcian blue specimens. The probable reasons for the precipitation of saliva by the Alcian blue are discussed. The possible nature, origins and functions of the Ruthenium red and Alcian blue positive surface covering are discussed.
Cell attachment to demineralized root surfaces in vitro
Authors: Boyko G. A. , Brunette and D. M. , Melcher A. H.
Published: July 2006

The periodontal ligament and crowns were removed from extracted porcine molars and the surface area of each root was determined. Cultured fibroblast‐like cells derived from periodontal ligament were allowed to attach in vitro to the roots, some of which had been demineralized for various periods of time in citric, hydrochloric or ethylenediamine tetraacetic acid. The number of cells that had attached to each root was then counted and expressed as the number of cells per unit area. Significantly more cells attached to demineralized roots than to non‐demineralized roots, the method of demineralization not influencing the result. The number of cells that attached to both citric acid‐demineralized roots and non‐demineralized roots increased with time up to 8 h. Scanning electron microscopy confirmed that 3 min of demineralization in citric acid exposed collagen of the root, and that cells attached to both demineralized and mineralized roots. The results suggest that one of the ways in which citric acid‐demineralization of root surfaces could contribute to the reported enhancement of healing of periodontal defects is by improving the attractiveness of the root surface as a substrate to which cells can adhere.
Fine structural observations on the mechanism of loss of attachment during experimental periodontal disease in the rat
Authors: Deporter D. A. , Brown D. Y.
Published: July 2006

Severe periodontal destruction was produced unilaterally in rats by placing a wire/Concise appliance to encourage plaque accumulation, and then feeding the animals a high carbohydrate diet for up to five months. Electron microscopic examination of the specimens, which comprised maxillary first and second molar periodontium, at the ligament‐cementum interface revealed distinct zones in the destructive process. These included a zone of complete loss of ligament attachment to cementum just apical to the crevicular epithelium, and leading into a zone of partial loss of attachment where the destruction was occurring. Fibroblasts in this zone of partial loss were observed to resorb ligament fibrils inserted into cementum by phagocytosis and intracellular degradation. The same cells appeared to be phagocytosing the substance of the cementum as well. The remainder of the ligament apical to the zone of partial loss comprised the third zone and represented a more normal attachment apparatus.
Comparative colonization of human Actinomyces species in hamsters under different dietary conditions
Authors: Behbehani M. J. , Jordan H. V.
Published: July 2006

Oral colonization of hamsters by Actinomyces species of human origin was studied. Strains of A. viscosus and A. naeslundii became implanted while strains of A. israelii, A. odontolyticus and Arachnia propionica did not. A glucose diet was superior to a sucrose diet for A. viscosus and A. naeslundii implantation. A. naeslundii appeared to colonize the animals at a slower rate. Suppression of the oral‐intestinal flora by a short‐term pretreatment of 3–7 days or continuous exposure to dietary streptomycin sulphate also improved implantation of streptomycin‐resistant strains of these 2 species. An experimental period of 3–6 months was required for development of gross deposits of cervical plaque and periodontal pathology.
Longitudinal aspects of gingival width
Authors: Mazeland G. R. J.
Published: July 2006

Measurements of gingival width at upper and lower incisors in 30 male adults were compared to those taken five and a half years previously. A slight increase in gingival width at the upper incisors was found. At the lower incisors the width of the gingiva did not increase. The relevance of these findings with regard to the increase in lower face height in adults was discussed. It has been postulated that this increase occurs within the area of the alveolar processes and is due to eruptive movements of the teeth and their supporting tissues. The findings of the present study also point to an increase in gingival width. However, the findings must be interpreted with caution. It is questionable whether at the present time adequate techniques are available to measure changes in gingival width in adults, as the so called adult growth is almost imperceptibly small.
Functional integrity of gingival crevicular neutrophil polymorphonuclear leucocytes as demonstrated by nitroblue tetrazolium reduction
Authors: Kowolik M. J. , Raebukn J. A.
Published: July 2006

Gingival crevicular neutrophils were collected from 20 healthy subjects and their ability to reduce nitroblue tetrazolium was investigated by means of a semi‐quantitative histochemical test. 78.04 % (± s.e.m. 0.8 %) of the cells were vital. 42.9 % (± s.e.m. 3.3 %) of the crevice neutrophils were NBT positive as compared to 5.6% (± s.e.m. 0.89%) of unstimulated peripheral venous blood neutrophils from the same patients (p < 0.001). No difference between male and female was found. The results indicate a stimulation of crevicular neutrophils by bacteria. Furthermore, a slight correlation between blood and crevicular neutrophil activity in each individual was found, suggesting that even in the normal state some antigen or other bacterial product in the circulation is capable of stimulating the neutrophils.

One patient with hereditary cyclical neutropenia, shown to have a greatly reduced number of crevicular cells, had normal activity of both blood and crevicular neutrophils as measured by this test. These findings, compatible with known immunological results, are compared with the neutrophil function test results in this patient and two other neutropenic subjects.

This study supports the view that the gingival crevicular neutrophil is a functional cell capable of contributing towards host defense.
Stimulation of lysosomal enzyme release from macrophages by lipoteichoic acid
Authors: Harrop P. J. , O'Grady R. L. , Knox K. W. , Wicken A. J.
Published: July 2006

Preparations of lipoteichoic acid (LTA) from strains of streptococci and lactobacilli were examined for their ability to stimulate the release of enzymes from rat peritoneal macrophages in vitro. The three lysosomal enzymes, acid phosphatase, N‐acetyl‐β‐D‐glucosamini‐dase and β‐galactosidase, were detected but not collagenase. Generally, the secretion of the lysosomal enzymes was not inhibited by cychloheximide, indicating that only preformed enzyme was being released. In contrast, cycloheximide partially inhibited the release of lysosomal enzymes by lipopolysaccharides (LPS).
Histological and ultrastructural characteristics of the periodontal syndrome in the rice rat
Authors: Ryder Mark I.
Published: July 2006

In this study on the periodontal syndrome in the rice rat, observations were made on rice rats fed stock diet and followed from six days to fifteen weeks after birth, and on rice rats fed a high sucrose diet (Diet 700) from weaning (3 weeks after birth) and followed to seventeen weeks after birth.

In rats fed stock diet, early massive accumulations of bacterial plaque were seen on erupting posterior teeth with an underlying PMN exudate and a PMN infiltrate within the gingival epithelium and lamina propria. Inflammatory and resorptive changes were rarely seen in the transeptal fiber area and alveolar crest in this group of animals.

In rats fed diet 700, similar patterns of bacterial plaque accumulations and PMN infiltrations were seen. At later time periods, this PMN infiltrate was commonly seen to extend through the transseptal fiber area to the alveolar crest where marked osteoclastic activity was noted. Such apical extension of the inflammatory infiltrate was associated with ulceration of the overlying gingival epithelium.
Inflammatory reactions in the gingival region during the development of bacterial plaque in alloxan‐diabetic dogs
Authors: Matsson L. , Attstrom R. , Granath L.
Published: July 2006

The effect of experimentally induced diabetes on inflammatory reactions in the gingival region of the beagle dog has been studied in connection with the development of dental plaque.

The investigation, which was undertaken in 5 dogs, had an intra‐individual design, the increases in the amounts of gingival exudate and crevicular leukocytes during plaque development being studied in each animal before and after the induction of alloxan‐diabetes.

The increases in gingival exudate and crevicular leukocytes in response to plaque accumulation showed a tendency to be lower during diabetic compared with non‐diabetic periods. It is suggested that the lower vascular reaction and the reduced leukocyte migration that were observed shortly after onset of the experimental diabetes might reflect an impaired defense mechanism of importance in the longer run for the development of pathological changes in the periodontium.
Prostaglandin E and the local immune response in chronic periodontal disease
Authors: Löning TH. , Albers H.‐K. , Lisboa B. P. , Burkhardt A. , Caselitz J.
Published: July 2006

The local immune reaction of progressive chronic periodontal disease may be particularly influenced by macrophages and macrophage‐derived factors. Among these substances the prostaglandins and lysosomal enzymes may play an important pathogenetic role. Parallel immunohistochemical and radioimmunological studies were done to investigate the relationships of the immune‐competent cells and the inflammatory mediators in gingival tissues. The radioimmunological analysis revealed that prostaglandin E increases markedly in the established gingival lesions. Immunohistochemically prostaglandin E was mainly localized within macrophage‐like cells. Cytoplasmic lysozyme could be detected in these cells, too. On the other hand, the B‐cell response is the prominent feature in established chronic periodontal disease. However, there is apparently a disturbed B‐cell reaction as indicated by the irregular IgG‐subclass pattern and by the production of mainly monomeric IgA. The possible interactions of macrophages and especially B‐cells via prostaglandin E‐mediated mechanisms are discussed.
The effect of parathyroid hormone on the numbers of nuclei in feline odontoclasts in vivo
Authors: Addison W. C.
Published: July 2006

Odontoclasts exhibit varying numbers of nuclei. The purpose of the present study was to determine the effect of a low dose (4 USP units per 100 g. body weight) of parathyroid hormone extract (PTE) in vivo on the numbers of nuclei in whole feline odontoclasts. Odontoclasts were recovered in smear type preparations from the resorbing primary teeth of 12 kittens aged approximately 18 weeks. Four kittens had received PTE intravenously one hour prior to sacrifice, four six hours previously, and four were controls. The fresh smears were allowed to dry and subjected to dehydrogenase enzyme histochemical reactions. The unstained odontoclast nuclei contrasted with the stained cytoplasm and were counted at a magnification of × 125. The three groups had similar distribution patterns of nuclei per cell but progressive increases in the mean and median numbers of nuclei per cell were found following PTE treatment. The mean in control animals was 7.0 S.E. ± 0.12 and in the PTE 1 hour and PTE 6 hours groups was 8.0 S.E. ± 0.12 and 8.9 S.E. ± 0.12 respectively. The median values were 5.5, 6.6 and 7.3 respectively. The differences between both the control and PTE 1 hour, and between the PTE 1 hour and PTE 6 hours groups were statistically significant (p < 0.001). This rapid increase in the numbers of nuclei in odontoclasts after PTE treatment has not been reported previously.
The effect of topical citric acid application on the healing of experimental furcation defects in dogs
Authors: Nilvéus R. , Bogle G. , Crigger M. , Egelberg J. , Selvig K. A.
Published: July 2006

In a previous study, citric acid‐conditioning of the root surface greatly improved the rate of success of new‐attachment procedures in periodontal furcation pockets in mandibular premolars of Labrador retrievers (Crigger et al. 1978). In the present study, this experimental approach was tested in six beagles. The furcations on one side in each dog were reoperated six weeks after the first surgery. In 27 of the 35 treated teeth, mesiodistal sections showed closure of the furcation and new connective tissue attachment including deposition of new cementum. The extension of new attachment in the buccolingual dimension of the furcation, however, was not improved by repeating the surgical procedure.
Histological and ultrastructural characteristics of the periodontal syndrome in the rice rat
Authors: Ryder Mark I.
Published: July 2006

The periodontal syndrome in the rice rat was studied in animals fed a high sucrose diet. Progressive degenerative and inflammatory changes within the coronal aspects of the rice rat psriodontium (viz. sulcus, epithelium and lamina propria) were noted. PMN's were seen to migrate from blood vessels within the lamina propria, through the basal lamina, and to either the cemental surface or to the bacterial plaque, where a minimal degree of PMN phagocytosis and degranulation was observed. The degree of PMN phagocytosis appeared to be inversely related to the density of bacterial plaque as viewed on the electron microscopic level.

Progressive degenerative changes (viz. vacuolization, lipid accumulation, mitochondrial swelling, etc.) were seen in gingivai epithelial cells subjacent to the bacterial plaque, as well as at the basal layer. Similar changes were noted in fibroblasts in the underlying lamina propria. At later stages of observation (8–14 weeks post‐weaning) a prominent population of macrophages and mononuclear cells was seen within the lamina propria. “Clumping” of these cell types with degenerating fibroblasts was a common finding.
Histological and ultrastructural characteristics of the periodontal syndrome in the rice rat
Authors: Ryder Mark I.
Published: July 2006

In this study on the periodontal syndrome in the rice rat, the progressive inflammatory and degenerative changes were noted in the transseptal fiber area and alveolar crest.

The predominant inflammatory cell types within the transseptal fiber area were PMN's, monocytes and macrophages. Progressive degenerative changes were noted in fibroblasts and collagen fibers with replacement of these elements by the inflammatory infiltrate.

At the alveolar crest, extensive osteoclastic activity was observed. Expressions of this activity included the presence of prominent osteoclast ruffled borders and osteoclastic phagocytosis of osteocytic cells. Degenerative changes within osteoblasts were noted at later stages.

From these observations, the accelerated rate of destruction seen in this animal model can be explained in part by the increase in resorptive elements (macrophages, osteoclasts) with the simultaneous decrease in formative elements (epithelial cells, fibroblasts, osteoblasts).
Quantitation of in vitro cell adhesion to cementum, dentin and enamel
Authors: Brastins E. D. , Labant M. , Fletcher R. D.
Published: July 2006

The William's blister test for adhesion was used to determine the strength of epithelial and fibroblast cell attachments to cementum, dentin and enamel. Differences of air pressure required (cm H2O) to debond the samples from a cell monolayer were measured and recorded on a strip chart recorder (Fletcher et al. 1977).

Gingival and skin‐muscle cells detached at similar pressures from cementum, dentin and enamel. Higher pressures (of debond) were required with cells grown on a polystyrene surface.
DNA homologies among Eikenella corrodens strains
Authors: Coykendall Alan L. , Kaczmarek Frank S.
Published: July 2006

Deoxyribonucleic acids were extracted from 22 Eikenella corrodens strains of human oral origin. The DNA's were compared by determination of their base contents (mol % G + C), and by DNA hybridization on membrane filters and in solution using Sl nuclease. DNA was radioactively labeled in vitro by use of DNA polymerase and labeled triphosphate bases. On membrane filters, DNAs hybridized at least 70 % with labeled strains. Mean base contents were between 55.7 and 57.2 mol % G + C with an overall mean of 56.3. It was found that the labeled DNA was somewhat sensitive to Sl nuclease and this produced variations in hybridization when the Sl method was used although no heterogeneities were apparent. The strains had similar biochemical properties. They produced only slight amounts of acetic acid in Todd‐Hewitt broth. These human oral strains appeared to be a biochemically and genetically homogenous group.
Angular changes in collagen cemental attachment during tooth movement
Authors: Sims Milton R.
Published: July 2006

Intrusion and extrusion springs were applied in pairs to mandibular first molars of mice. Treatments were randomly allocated to the right and left sides of the jaw in both normal and lathyritic animal groups. Histologic sections revealed that principal collagen fibres demonstrated extensive changes in their cementum attachment angles when comparing matched intrusion‐extrusion pairs in either normal or lathyritic animals. A mixed model analysis of variance of the angular readings showed a significant difference at the 1 % level in the angle attributed to the type of treatment applied. These data lent support to the hypothesis that collagen fibres and oxytalan fibres undergo opposite and complementary changes during intrusive and extrusive tooth movement.
Inhibition by chlorhexidine of alveolar bone loss in mice
Authors: Messer H. H. , Douglas W. H.
Published: July 2006

Use of 0.2 % chlorhexidine gluconate as a mouthrinse 5 times per week for 6 months inhibited alveolar bone loss by more than 40 % in a strain of periodontal disease‐susceptible mice.
Marginal fit and cervical extent of class II amalgam restorations related to periodontal condition
Authors: Arneberg Pål , Silness John , Nordbø Håkon
Published: July 2006

In 18 dental students, 314 class II amalgam restorations were examined by probe and mirror as well as by radiographs. The examination was repeated subsequent to amendment of defective restorations through finishing procedures. Plaque, gingivitis and pocket depths were recorded at the initial examination and six months after the finishing procedures.

Defects were found at the cervical margin of 50 per cent of the fillings at the first examination. Three out of four defects were overhangs, and five out of six overhangs were corrected by finishing. Overhangs, deep pockets and gingivitis were often recorded when the fillings extended beyond the gingival margin. On the other hand, neither the presence nor the elimination of moderately sized amalgam overhangs could be shown to influence the periodontal conditions.
The inhibition of human gingival collagenase by an inhibitor extracted from human teeth
Authors: Geiger Selly B. , Harper Elvin
Published: July 2006

The activity of human gingival collagenase was inhibited by an inhibitor found in an extract of human teeth. This inhibitor, denoted Human Dental Collagenase Inhibitor, was partially purified and found to selectively inhibit human skin and gingival collagenase, as well as tadpole collagenase, but not the bacterial collagenase (Clostridium histolyticum). On the basis of gel filtration analysis we determined that the inhibitor has an apparent molecular weight of approximately 12,000 daltons, similar to that reported for other tissue collagenase inhibitors.