bluuebunny/crossref_metadata_2025 huggingface dataset:
Alveolar bone loss in a strain of mice
Authors: Messer H. H.
Published: July 2006

Alveolar bone loss with increasing age was compared in strain STR/N and random‐bred Swiss‐Webster mice. All animals were fed pelleted laboratory chow and tap water and killed at 3 month intervals from 3–18 months of age. Alveolar bone loss was quantitated by measuring loss of alveolar crest height on the lingual aspect of the defleshed right hemimandible, and by planimetric measurement of the quantity of trabecular bone in a single undecalcified mesiodistal section of the same hemimandible. The left hemimandible was fixed in formalin and examined histologically. There was a progressive severe loss of alveolar bone with increasing age in strain STR/N mice, which was not observed in random‐bred Swiss‐Webster mice. Histologically, the bone loss was associated with progressive gingivitis and periodontal pocket formation. The bone loss was not related to hair or bedding impaction or to obvious dental morphological differences between the two strains. Systemic disturbances such as generalized osteoporosis or diabetes mellitus were not present. The occurrence of bone loss in STR/N mice in the absence of any applied stimulus suggests that this strain is suitable for studying mechanisms of alveolar bone loss and factors capable of modifying bone loss.
Salivary immunoglobulins in children with asthma
Authors: Hyyppä Tuula
Published: July 2006

Whole saliva of 30 children with extrinsic asthma was analyzed for IgA, IgG and IgE. Salivary albumin concentrations were also determined. The values were compared with those obtained from matched healthy controls. The salivary IgG, IgA and albumin values did not differ from their healthy controls. The IgE concentrations of the asthmatic children, however, were significantly higher. Those children who had recently received hyposensitization therapy showed slightly elevated values of IgE in their saliva. The different medication of the children with asthma did not affect any of the immunoglobulins studied.
Activation of complement by dental plaque
Authors: Okuda Katsuji , Takazoe Ichiro
Published: July 2006

Dental plaque samples and oral bacterial cells consumed complement (C) in human serum. No significant difference was found between the C binding ability of dental plaque samples from patients with periodontal disease and those of samples from healthy individuals. An analysis of C component profiles and immunoelectrophoretic patterns showed that dental plaque activated the C system through the alternative pathway as well as the classical pathway.

When pooled and dispersed dental plaque was preincubated with fresh serum, the purified C3 conversion and C3 cleaving were observed. The activity of the pretreated dental plaque disappeared gradually by further incubation with fresh serum at 37°C. These results suggest that dental plaque generates the C3‐cleaving enzyme activity.
Electron microscope quantitation of inflammatory infiltrates in childhood gingivitis
Authors: Longhurst Peter , Gillett Roy , Johnson Newell W.
Published: July 2006

Quantitation of inflammatory cell infiltrates in gingival connective tissues was carried out on 12 gingival biopsies from the deciduous dentition of 11 children aged 4–8 years. The tissue was prepared for electron microscopy and from ultrathin sections mounted on 200 mesh grids, cells in one third of the grid squares enclosing infiltrated connective tissue were counted.

The infiltrate displayed large numbers of small and medium lymphocytes and was moderately vascular. A distinct population of peripherally distributed plasma cells was present and pathologically altered fibroblasts together with marked collagen loss were notable features. Small numbers of macrophages, mast cells and polymorphonuclear neutrophils were recorded but T‐blasts (immunoblasts) were very rarely encountered.

The childhood lesions have much in common with the early lesion of adult gingivitis which is considered to be a cell‐mediated immune phenomenon. However, the lack of T‐blasts and rather larger proportion of plasma cells suggest that the lesion of childhood gingivitis represents a position between the early and established phases of gingival disease described in older individuals. A more exact interpretation of these, the earliest stages of human gingival disease should be achieved when the lymphocytes contributing to the childhood infiltrates can be assigned to the T‐ and B‐ cell lines.
Human gingival fibroblast cell lines in vitro
Authors: Yajima Toshihiko , Rose George G. , Mahan Charles J.
Published: July 2006

Eight human gingival fibroblast cell lines were cultivated in glass cover slip chambers and analyzed by electron microscopy for their capacity to synthesize an extracellular fibrillar matrix. Both microfibrils and amorphous components of elastic tissue and several forms of banded and unbanded collagen fibrils were elaborated by the fibroblasts. Banding periods of 64 nm and 100 nm were observed. Collagenases lysed collagen fibrils and in some cases altered them to display prominently banded FLS images. Numerous matrix vesicles were observed among the extracellular collagen fibrils and some were observed intracellularly either isolated in pinocytotic‐like vesicles or as clusters in larger vacuoles. Matrix granules also were observed among the extracellular fibrils. The Golgi sacs of synthesizing fibroblasts contained fine thread‐like parallel filaments with a banding period of 220 nm. The presence of annulate lamellae was related to culture aging and the appearance of large mitochondrial matrix granules was related to the effect of small increments of vitamin C. Two cells were shown to have phagocytosed collagen elaborated by other cells earlier, one contained an interiorized fibril with a 64 nm banding period and the other an interiorized fibril with a 100 nm banding period. A turnover of collagen in vitro was thus established.
Healing of periodontal connective tissues following surgical wounding and application of citric acid in dogs
Authors: Ririe Craig M. , Crigger Max , Selvig Knut A.
Published: July 2006

Topical application of citric acid to a root surface which has been scaled and root planed results in exposure of collagen fibrils of the dentin matrix. The purpose of this study was to examine the healing of gingival connective tissue adjacent to a root planed and subsequently acid conditioned root surface and to determine whether the exposure of dentin or cementum matrix collagen would facilitate the reestablishment of an attachment between the healing connective tissue and the root surface. Full thickness flaps were raised and labial alveolar bone removed over maxillary incisor roots of seven Labrador retrievers. The exposed root surface was planed before etching with citric acid (pH 1) for 3 min. The flap was then repositioned at its original level. Block sections were obtained after 7, 14, 21 and 42 days and the interface between the root surface and the healing wound tissue studied by light and electron microscopy. Compared to conventional flap surgery in the same animals, application of citric acid to the instrumented root surface resulted in an improved rate of connective tissue healing as well as a rapid and consistent reestablishment of connective tissue attachment through extensive interdigitation of new and old collagen fibrils at the tooth‐gingiva interface. Subsequent reinforcement of the established connective tissue attachment included recalcification of the acid‐affected dentin and deposition of new cementum.
Kielbone® in healing interradicular lesions in monkeys
Authors: Nielsen I. M. , Ellegaard B. , Karring T.
Published: July 2006

The purpose of this investigation was, to compare the histological features of Kielbone and autogenous jaw bone following transplantation into periodontal interradicular lesions in monkeys. Bifurcation defects were produced on mandibular molars and premolars. Kielbone was transplanted into 40 bifurcations while another 30 bifurcations received fresh autogenous cancellous jaw bone. The animals were sacrificed according to a schedule yielding observation periods up to 16 weeks. Before sacrifice the animals were perfused with a mixture of india ink and serum (3:1) by cannulization of the carotid arteries. The specimens were decalcified in a formic acid/sodium citrate solution. Cleared specimens 100μ of thickness were prepared from one half of each specimen. The other half of the specimen was cut into serial sections 8μ thick and stained with hematoxylin and eosin or Mallory's connective tissue stain. During healing of the treated defects Kielbone grafts and grafts of fresh autogenous bone from the jaws displayed similar histological features. In the bifurcation defects, Kielbone as well as autogenous bone grafts occured as isolated bone particles surrounded by a cementum‐like substance. It is suggested that Kielbone may constitute a suitable substitute for autogenous bone grafts in the treatment of periodontal intrabony defects. However, it should be emphasized that neither autogenous jaw bone nor Kielbone did favour bone regeneration in the bifurcation defects.
The mucogingival complexfitt relation to alveolar process height and lower anterior face height
Authors: Mazeiand G. R. J.
Published: July 2006

In 62 young adults the anatomical relationships between gingival width and vestibular depth on the one hand, and alveolar process height and lower anterior face height on the other hand, were studied. The gingiva was measured clinically with a periodontal probe, vestibular depth was measured indirectly with a mould method, and the bony parts of the lower anterior face were studied on 90° lateral cephalograms. The results showed, that gingival width is primarily related to alveolar process height. Although vestibular depth was closely related to gingival width, vestibular depth showed no relation to alveolar process height, nor did the width of the alveolar mucosa. It was concluded that gingival width is the main determinant of the vertical dimension of the vestibule. Gingival width was also found to be related to lower anterior face height; it was concluded that the same morphogenetic factors which are responsible for the vertical dimension of the lower face may be responsible for gingival width. The finding that gingival width was consistently smaller in females than in males substantiated further this conclusion, since females have smaller vertical facial dimensions than males.
Effect of electric currents on gingival cyclic nucleotides in vivo
Authors: Davidovitch Z. , Korostoff E. , Finkelson M. D. , Yost R. W. , Montgomery P. C. , Steigman S. , Shanfeld J. L.
Published: July 2006

Electric currents have been shown to affect a variety of tissues. The objective of this investigation was to determine whether the application of minute electric currents, non‐invasively, to cat gingival tissues would alter the immunohistochemical staining pattern of gingival cells for cyclic AMP and cyclic GMP, substances associated with cell stimulation. Three groups of 4 cats each were treated with an electric device delivering 15 ± 2 μamperes d. c. current to the gingiva near one maxillary canine for 1, 3 and 7 days, respectively. Horizontal sections of each maxilla were stained immunohistochemically for either cyclic AMP or cyclic GMP and intensely stained cells near the cathode and anode were counted. Near the cathode the number of gingival cells intensely stained for cyclic nucleotides was doubled by days 1 and 7 but not at day 3. Near the anode larger increases for both cyclic nucleotides were observed at all time periods. Changes were observed in the cellular staining patterns for cyclic AMP and cyclic GMP as a result of the electric stimulation suggesting activation of nuclear protein kinases. These results demonstrate that the stimulation of gingival cells by electric currents involves cyclic nucleotide fluctuations similar to those observed following the application of hormones and drugs.
Migration of gingival leukocytes mediated by plaque bacteria
Authors: Wennström Jan , Heijl Lars , Lindhe Jan , Socransky Sigmund
Published: July 2006

The present investigation was performed to study the leukocyte attracting capacity of sonicates from two different plaque bacteria using the dentogingival junction in dogs as a research model. The bacterial test substances consisted of saline suspended lyophilized sonicates of pure cultures of A. viscosus (Strain T14) and C. ochracea (Strain 6). Five animals were used. On Experimental Day I the conditions of the gingivae of the animals were assessed by Gingival Index scores and Gingival Exudate measurements. Following the registration of the clinical parameters, the first part of the study was performed. The various test and control (saline) materials were applied onto the gingivae in the right or left side according to a predetermined schedule. The gingival tissues were during an 8‐hour period continuously exposed to the test or control materials. Towards the end of the experiment, biopsies were obtained from the marginal gingiva. From tissue blocks representing the center of each gingival biopsy, sections were cut at 2–3 microns in the buccal/lingual plane and stained in PAS and toluidine blue. In the sections the number of leukocytes in the junctional epithelium was assessed. After an interval of one month (Experimental Day II) the clinical examination of the gingiva was repeated and the animals depleted of their serum complement by repeated injections of Cobra Venom Factor. The test and control materials were applied in a manner identical to that of Experimental Day I. The results demonstrated that topical application of sonicates of the two microorganisms studied onto the normal gingiva of dogs resulted in an increased number of neutrophils and mononuclear leukocytes in the junctional epithelium. Material from Strain 6 in comparison to material from Strain T14 appeared to contain only minor amounts of ‐ or less potent ‐leukocyte attracting components. The number of leukocytes in the junctional epithelium was markedly lower in animals with reduced serum complement levels.
The appearance of bone resorbing activity in ligature induced gingivitis in dogs
Authors: Soskolne W. A. , Nuki Klaus , Raisz Lawrence G. , Alander Cindy
Published: July 2006

The in vitro bone resorbing activity of extracts from healthy and inflamed dog gingiva were compared and the appearance of the resorbing factor between 1 and 6 weeks of gingivitis was measured. Seven adult dogs were used. The gingiva were initially rendered healthy by scaling and polishing. Plaque retentive ligatures were placed around the necks of teeth so that at the end of the experiment samples of healthy gingiva and gingiva with 1 and 6 week old ligature induced gingivitis could be harvested from each dog. The bone resorbing activity of extracts from these gingival samples was studied by measuring the release of 45Ca from prelabeled fetal rat long bones in organ culture. Six out of 7 extracts from healthy quadrants had no bone resorbing potential whereas 13 out of 14 extracts from ligatured quadrants stimulated significant amounts of bone resorption. The resorbing activity appeared during the first week after ligature placement and no significant increase in resorbing potential was noted between extracts obtained 1 and 6 weeks after ligature placement. It was concluded that the appearance of the bone resorbing factor(s) is related to the accumulation of plaque and/or the resultant inflammation and that it may be responsible for the alveolar bone loss seen in ligature induced periodontal disease in dogs.
Periodontal disease in the beagle dog A cross sectional clinical study
Authors: Sorensen William P. , Löe Harald , Ramfjord Sigurd P.
Published: July 2006

A cross sectional study was done in seventy‐four beagle dogs from one to twelve years of age. Gingivitis, calculus, plaque, loss of attachment, pocket depth and width of keratinized gingiva were scored and descriptive statistics calculated.

Gingivitis differed very little in the maxillary and mandibular incisor and canine regions at differing ages, while it was more severe on the buccal gingiva of premolars and first molars. Calculus scores were highest on the buccal surface of the maxillary P4 followed by the buccal surfaces of the maxillary Ml and mandibular P4. Plaque scores were high for the very young dogs and showed only slightly to moderately higher values with increasing age. The buccal surface of the maxillary P4 had the highest plaque score, followed closely by the buccal surfaces of the maxillary M1 and mandibular P4. Plaque scores were low in the incisor regions and on the lingual surfaces. On the buccal surfaces plaque scores increased from the C to P4, and then decreased in the molar regions.

Loss of attachment was minimal for anterior teeth and was greater in the premolar and maxillary M1 regions with older age. The greatest loss occurred on the distal surface of the maxillary P4, the mesial surface of maxillary M1, and distal surface of mandibular P4. The greatest difference existed between younger dogs and those older than six to seven years. Greater pocket depths were not generally proportionate to the greater loss of attachment, since recession accompanied loss of attachment. Pocket formation was found most often at the distal surface of the mandibular P4 in dogs six to seven years of age. The width of keratinized gingiva varied only slightly and inconsistantly with age, except that slightly narrower widths were found at six to seven years of age.

Periodontal disease in the beagle dog occurred in specific areas with a high plaque accumulation in young dogs and more gingivitis, calculus formation, and loss of attachment in older animals.
Periodontal disease in gnotobiotic rats
Authors: Heijl L. , Wennström J. , Lindhe J. , Socransky S. S.
Published: July 2006

The present investigation was carried out in order to assess the development of periodontal disease in germfree rats infected with microorganisms associated with human gingivitis, periodontitis and periodontosis lesions. One hundred and forty gnotobiotic rats of the Spraque‐Dawley strain were weaned 21 days after birth and then randomly divided into five groups (four experimental groups and one control) consisting of 28 animals each. After weaning the animals of the experimental groups were infected with one of the following strains; strain I (Actinomyces naeslundii), strain 1073 (Eikenella corrodens), strain 381 (Bacteroides asaccharolyticus), strain 4 (Capnocytophage sputigena). Animals were sacrificed to provide specimens for examination 14, 28, 56 and 84 days after infection. Germ‐free controls were sacrificed at the same time intervals.

The degree of alveolar bone loss was assessed on defleshed and dried jaws. Microscopic assessments regarding loss of connective tissue attachment, degree of bone resorption, and degree of impaction of hair and bedding material were determined in histological sections. In addition, a morphometric analysis of the gingival tissues was carried out using a standardized morphometric test procedure.

The results showed that germfree rats monoinfected with different bacteria associated with human periodontal diseases may suffer severe breakdown of the periodontal tissues. The degree of breakdown tended to increase with increasing experimental time. However, periodontal tissue destruction was obviously related to the impaction of hair and bedding material. In fact, only in areas with severe impaction of foreign material could gross destruction of the supporting apparatus be recognized.
Age‐related changes in the periodontium of pigtail monkeys
Authors: Ive John C. , Shapiro Peter A. , Ivey Joel L.
Published: July 2006

Age‐related changes in the periodontia of maxillary lateral incisors were studied in the pigtail monkey (Macaca nemestrina). Transverse sections were obtained from the crestal and apical middle third of the roots from specimens of ages 3 and 4 years (N = 2), 10 years (N = 3), and 20 years (N=3). With increasing age, the roots migrated toward the labial cortical plate, resulting in the development of a bony root prominence on the labial periosteal surface. Quantitative histomorphometric measurements in conjunction with analysis of variance were used to isolate the effects of age and section level on the parameters of interest. The areas of the alveolar socket and cementum increased significantly with age, as did cemental thickness. The width of cementum on the lingual surface was significantly greater than the width on the other surfaces, probably as a response to the labial migration of the tooth. The width and relative area of the periodontal ligament space decreased significantly with age, suggesting that the deposition of cementum proceeded at a rate slightly greater than that at which the socket was enlarging. The number of blood vessels in each quadrant of the periodontal ligament were counted, and no significant difference was found among the different age groups. There were, however, significantly more blood vessels in sections from the crestal third than in those from the apical third of the roots.
Collagenolytic activity of periodontal ligament and hydroxyproline content during human deciduous root resorption
Authors: Alexander Stanley A. , Swerdloff Mark
Published: July 2006

The periodontal ligaments of human resorbing deciduous teeth were analyzed biochemically for collagenolytic activity. Total hydroxyproline content of dentine was also measured. Activity was present in resorbing teeth, while control teeth exhibited no activity. Concomitantly, hydroxyproline levels were approximately 43 percent lower in resorbing teeth (8.2 grams percent) than in control teeth (14.4 grams percent), representing a significant difference between the two groups.

These results appear to support the concept that collagenolytic activity is responsible, in part, for physiological resorption.
Oral mucosa of the vervet monkey
Authors: Fleisch L. , Cleaton‐Jones P. , Austin J. C.
Published: July 2006

Specimens of oral mucosa were taken from alveolar mucosa, attached gingiva, cheek, floor of mouth, hard palate, lip, soft palate and tongue from vervet monkeys (Cercopithecus aethiops), and prepared for histological and histometric examination. Masticatory mucosa showed an epithelial‐connective tissue union comprised of prominent thin rete pegs and connective tissue papillae. Lining mucosa had broader rete pegs and short connective tissue papillae. Elastic fibres were seen in all tissues except hard palate and attached gingiva. Histometric examination showed considerable variation in epithelial width and cell densities between the various epithelia. Tongue had the widest epithelium and alveolar mucosa the narrowest. Cell density was greatest in alveolar mucosa and least in cheek and floor of the mouth epithelium.
Identification of cells expressing T and p28,33 (la‐like) antigens in sections of human chronic inflammatory periodontal disease
Authors: Seymour G. J. , Greaves M. F.
Published: July 2006

Previous studies have indicated that the lymphocytes present in progressive human chronic inflammatory periodontal disease may be of B‐cell origin. The present investigation was undertaken to determine the usefulness of specific antisera to lymphocyte differentiation antigens in identifying the cell subpopulations in situ in the chronic inflammatory lesion. Both HuTLA+ (5–10%) and p28,33+ (90–95%) cells were identified. Although the p28,33+ population may include macrophages and a subset of T‐cells, the majority of cells are probably of B‐cell origin. This supports earlier suggestions that progressive periodontal disease in humans is a B‐cell lesion and demonstrates that antisera to lymphocyte differentiation antigens in an immunofluorescence assay will delineate cell subpopulations in situ in a chronic inflammatory lesion.
Gingival crevice neutrophil function in periodontal lesions
Authors: Murray Patricia A. , Patters Mark R.
Published: July 2006

Polymorphonuclear neutrophils (PMN) may play an important role in protection of the host from pathogenic microorganisms associated with periodontal tissue destruction. The purpose of the present study was to test the hypothesis that unusually severe periodontitis may be associated with defective PMN function at the local disease site. The patients studied included young patients with rapidly progressive periodontitis (including juvenile periodontitis), age‐matched patients with gingivitis, and older patients with chronic periodontitis. Gingival crevice (GC) PMN were collected from 10 lesions of each patient by a crevicular washing technique. The number and viability of GC PMN recovered were determined. Their phagocytic capacity was assayed in vitro as a percentage of cells capable of engulfing latex particles. No differences were observed between the periodontitis groups in the number or viability of GC PMN recovered. A statistically significant reduction in mean phagocytic capacity was observed in PMN recovered from lesions of rapidly progressive periodontitis when compared with lesions of chronic periodontitis (12.9 ± 2.1 % vs. 83.7 ± 4.8 %). GC PMNs recovered from non‐diseased sites of patients with localized juvenile periodontitis did not show this decreased function. These results suggest that locally diminished PMN function in rapidly progressive and juvenile periodontitis is associated with the environment of these lesions.
Interaction of inflammatory cells and oral microorganisms
Authors: Passo S. A. , Tsai C.‐C. , McArthur W. P. , Leifer C. , Taichman N. S.
Published: July 2006

Polymorphonuclear leukocytes (PMNs) come in contact with plaque microorganisms in the gingival sulcus. However, little is known about the ability of PMNs to kill or inhibit the growth of plaque microorganisms. In this study, the bactericidal effects of human PMNs and serum against S. mutans 6715, S. sanguis M5, and A. viscosus T14 virulent and avirulent were examined. Plaque microorganisms grown to stationary phase were incubated with human PMNs and/or serum for 90 minutes at 37°C. The killing and growth inhibition of bacteria were determined by measurement of percent reduction in colony forming units and percent inhibition of 3H‐uridine uptake by the microorganisms. A. viscosus T14 virulent was the only microorganism significantly killed by human PMNs in the absence of serum. In the presence of fresh but not heat‐inactivated (56°C, 30 minutes) human serum, human PMNs had a significant bactericidal effect against all of the microorganisms tested. Exposure of S. mutans 6715, but not S. sanguis M5, to sucrose inhibited the bactericidal effect of human PMNs in the presence of fresh human serum but not in the presence of rabbit anti‐S. mutans immunoglobulin. Cytochalasin B markedly inhibited phagocytosis of S. mutans 6715 by human PMNs in the presence of serum. However, cytochalasin B‐treated PMNs still were significantly bactericidal for S. mutans 6715 in the presence of serum. The data suggests that human PMNs may kill or inhibit the growth of certain plaque microorganisms in the gingival crevice. The microbial killing may be influenced by bacterial extracellular polysaccharides and the presence of serum antibodies and complement, both resulting in phagocytosis and extracellular lysosomal release from PMNs.
The effect of topical citric acid application on the healing of experimental furcation defects in dogs
Authors: Nilvféus Rolf , Egelberg Jan
Published: July 2006

Chronic periodontal disease was induced and through‐and‐through furcation pockets created in mandibular premolars in two groups of beagles consisting of five and six animals respectively. The furcation defects were treated by surgical debridement supplemented with citric acid conditioning of the instrumented root surface. The relative importance of three adjunctive therapeutic measures was assessed. Thus, the effect of systemic antibiotics was evaluated by inter‐group comparison. Gelfoam as a matrix support for the blood coagulum during healing was evaluated by intraindividual, contralateral comparisons in one group of animals. Coronal repositioning of the muco‐periosteal flaps was evaluated by contralateral comparisons in the second group of animals. Block specimens for histological evaluation were removed six weeks after surgery. A high rate of regeneration and new attachment of the furcations was obtained irrespective of the use of systemic antibiotics, Gelfoam and high or low flap positioning. Thus, topical acid application seems to be the crucial therapeutic factor in achieving new attachment in the present model of through‐and‐through furcation pockets.
Bacterial penetration in the apical pocket wall of advanced human periodontitis
Authors: Frank R. M.
Published: July 2006

The presence of bacteria in the apical wall of periodontal pockets has been observed in 8 cases of advanced human chronic periodontitis out of a total of 14 patients studied. The apical junctional epithelium and the underlying connective tissue were removed under general anesthesia. Filaments, rodshaped and coccoid microorganisms with predominant Gram‐negative cell walls were observed in the enlarged epithelial intercellular spaces. In the connective tissue, these microorganisms were found among badly damaged cellular fragments and collagen fibrils. Between the apical sub‐gingival plaque and the junctional epithelium of the pocket wall, several layers of polymorphonuclear leukocytes were observed with numerous phagosomes showing engulfed bacteria. Bacterial invasion of the apical wall of the pockets is possible in the final stages of human chronic periodontitis.
Characterization of toxic extracts of in vitro cultured human plaque
Authors: Singer R. E. , Buckner B. A.
Published: July 2006

Studies were conducted to characterize the water soluble cytotoxic substances elaborated in vitro by cultured human plaque. A complex bacterial plaque, derived from scrapings of whole human plaque, was cultured in a programmable culture apparatus. Exposure of tissue culture media to the cultured plaque rendered it toxic to mouse L929 fibroblasts. This toxic activity was not alleviated by addition of exogenous tissue culture nutrients, fractionated with a molecular weight of less than 1000 daltons and was heat stable. Water extracts of the cultured plaque contained similar low molecular weight toxic factors. In contrast, extracts prepared from vigorously disrupted plaque contained high molecular weight toxins which were in part sensitive to heat inactivation. These findings demonstrate that a heterogenous cultured plaque does elaborate water soluble toxins and that such factors represent only a fraction of the total complement of water soluble toxins contained within that plaque.
Effect of essential fatty acid deficiency and high fat diet on fatty acid composition of rat gingiva
Authors: Alam Syed Q. , Alam Bassima S.
Published: July 2006

The fatty acid composition of total lipids of rat gingiva was significantly altered in essential fatty acid (EFA) deficiency. The changes consisted of an increase in the levels of palmitoleic and oleic acid, a decrease in linoleic and arachidonic acid and an accumulation of 5,8,11‐eicosatrienoic acid (20:3 ω9) in gingival lipids of EFA‐deficient rats. Reduction in arachidonic acid induced by EFA deficiency may result in lower prostaglandin levels in gingiva. Increasing the dietary level of corn oil from 7 % to 20 % did not result in a further increase in arachidonic acid levels in gingiva.
Decreased alveolar bone resorption in rice rats treated with chlorhexidine and stannous fluoride
Authors: Leonard E. P. , Reese W. V. , Benson C. L. , Cecil J. C.
Published: July 2006

Rice rats were used to test the effect of topically applied chlorhexidine gluconate and stannous fluoride on the loss of periodontal bone. Eighty‐eight weanlings were divided into eight groups of eleven animals each. Four groups were swabbed five times each week with either: a) 0.2 % chlorhexidine; b) 2 % chlorhexidine; c) 0.2 % chlorhexidine and 10 % stannous fluoride combined, or d) deionized water. Four other groups were swabbed only twice (once at the start and once at day 30) with either: e) 0.2 % chlorhexidine; f) 10 % SnF2; g) 0.2 % chlorhexidine and 10 % SnF2, or h) deionized water. After two months the animals were killed and the mandibular quadrants scored to estimate bone loss. Concentrations of 0.2 and 2 % chlorhexidine applied five times per week and 10 % SnF2 applied only twice, significantly reduced bone loss when compared to the deionized water control. The more frequent applications had a significant beneficial effect as compared to the less frequent applications.
Junctions between fibroblasts in mouse periodontal ligament
Authors: Beertsen W. , Everts V.
Published: July 2006

Quantitative evaluation of the distribution of intercellular junctions between fibroblasts in the incisor and molar periodontal ligament of the mouse indicated that structures resembling gap junctions are more frequent on the tooth side of this tissue than on the bone side. The difference was particularly evident for the ligament of the continuously erupting incisor. Here, the numerical density of gap junction‐like structures was estimated to be approximately 20 per fibroblast in the connective tissue adjacent to the cementum and 4 per fibroblast in the tissue along the alveolar bone. With regard to the distribution of adhaerens‐type junctions less variation was observed between the various zones of the incisor and molar ligament. For the incisor the average number of adhaerens‐type junctions was calculated to be in the order of 30 junctions per cell in the tooth‐related compartment and 20 junctions per cell in the alveolar compartment.

Although in the molar intercellular junctions were observed throughout the entire width of the ligament, in the incisor they were confined to the two main connective tissue compartments, i.e. the one of the tooth side which moves with the erupting tooth in the direction of the oral cavity, and the one of the bone side which remains stationary with respect to the alveolar wall. In the transitional area between the two latter compartments junctions were very sparse. It is suggested that the distribution pattern of intercellular junctions between fibroblasts in mouse periodontal ligament reflects functional differences among the cells in the various regions of the tissue, differences that are possibly related to processes involving the movement of cells and the metabolism of collagen.
Quantitative analyses of osteoclasts, bone loss and inflammation in human periodontal disease
Authors: Rowe Dorothy J. , Bradley Lisbeth Schultz
Published: July 2006

Human autopsy specimens bearing posterior teeth with interproximal areas were studied by quantifying various histological parameters. Osteoclasts were found to be equally frequent on the crestal, alveolar wall and endosteal alveolar bone surfaces. Evidence of previous resorption in the form of scalloping suggested that osteoclastic activity had also occurred in the past. The size of the inflammatory infiltrate was significantly correlated with the degree of bone loss, but not with the number of osteoclasts. However, the distance from the apical border of the inflammatory infiltrate to the alveolar bone crest was significantly correlated with both the number of osteoclasts on the alveolar crest, as well as their total number. These findings in the human periodontitis lesion support those from the animal model system which have indicated that the proximity of the inflammatory infiltrate to the bone surface is a significant factor in the osteoclastic resorption of alveolar bone.
The effect of cyclosporin A on periodontal disease in rats monoassociated with Actinomyces viscosus Ny 1
Authors: Guggenheim B. , Gaegauf‐Zollinger R. , Hefti A. , Burckhardt J. J.
Published: July 2006

The T‐cell triggered effector systems have been emphasized as the most important agents mediating periodontal disease in recent years. It was therefore tempting to investigate whether T‐cell suppression with cyclosporin A (CS‐A) had an effect on the establishment and progression of the disease in rats monoassociated with Actinomyces viscosus Ny 1. The experiment was carried out with two treatments (16 rats each) in two isolators. In one of the isolators CS‐A was added to the high sucrose diet 2000 aiming at a dosage of 15 mg per day and kg bodyweight. In the second isolator (control) the same diet without CS‐A was fed. At day 25, 38, 52 and 65 four animals from each treatment were removed from the isolators. Dental plaque and alveolar bone loss were evaluated. The cellular composition of blood and histological changes of periodontal lesions on a light and electron microscopic level were monitored. In addition antibody titers and the T‐cell suppressing effect of individual serum samples of all animals were determined.

Despite clearcut treatment differences in antibody titers as well as an interference by the sera of CS‐A treated animals with the Con A dependent lymphocyte activation, bone loss was observed in both groups. Haematological and histological investigation revealed only minor differences between the two treatments. It is concluded that periodontal disease in monoinfected rats seems to be the result of a multitude of pathomechanisms and not to be strictly correlated with T‐cell dependent hypersensitivity.
Histological and ultrastructural characteristics of the periodontal syndrome in the rice rat
Authors: Ryder Mark I.
Published: July 2006

In this paper on the periodontal syndrome in the rice rat, the effects of dietary penicillin and tetracycline on the progressive inflammatory and degenerative changes (as seen in rice rats fed diet 700 alone) were noted at the light and electron microscopic level. Throughout the observation period (0–14 weeks postweaning), animals fed diet 700 with penicillin or diet 700 with tetracycline showed no evidence of bacterial colonization, a minimal PMN infiltrate restricted to the gingival epithelium and subjacent lamina propria, and no marked degenerative changes within cells that normally inhabited the periodontium (viz. epithelial cells, fibroblasts, osteoblasts). Marked osteoblastic or osteoclastic activity was rarely noted along the alveolar crest in this group of animals.

These results give added support to the concept of a single microbial agent or group of microbial agents, as the primary etiology of this disease.
Measurement of blood flow in attached gingiva of dogs following brushing
Authors: Nuki K. , Hock J. , Schlenker R. , Hosain F.
Published: July 2006

A 133Xenon clearance technique was used io measure blood flow in the capillary bed of non‐inflamed attached gingiva. Measurements were made before and after brushing in a standardized manner.

The results show that blood flow through attached gingiva is greater than in published data for skin and increases significantly with brushing. The increases measured, however, are much smaller than those reported for skin under similar stimuli.

It is concluded that the high flow within unbrushed attached gingiva may be nearer the maximal possible flow than is the case for skin. The smaller increases measured as a result of brushing the gingival tissues may therefore represent a near maximal microcirculatory response.
Formation of new periodontalligament by periodontal ligament cells implanted in vivo after culture in vitro
Authors: Boyko G. A. , Melcher A. H. , Brunette D. M.
Published: July 2006

The premolar teeth were extracted from eight dogs, and cells from their periodontal ligaments and from attached gingiva were cultured in vitro. The lateral incisors were extracted later, the periodontal ligaments and pulps removed and the root canals filled. The roots were demineralized for 48 h in 0.5M EDTA, pH 7.4, and then divided into three groups. Cultured gingival cells were attached to those in the first group, psriodontal ligament cells to those in the second and no cells to those in the third which acted as controls. The roots were transplanted to holes drilled in the edentulous premolar region of the mandibular alveolar process and completely covered by a gingival flap, the roots and cells always being returned to the same dog from which they were removed. Because of infection, only 20 of the roots were recovered and, of these, only 4 bore periodontal ligament cells. All of the roots exhibited ankylosis and resorption. Only the roots bearing cultured periodontal ligament cells were associated with fragments of new fibrous tissue which was identified as periodontal ligament on the basis of the orientation of its fibres, the presence of Sharpey's fibres in bone and tooth, and cells located in positions normally occupied by osteoblasts and cementoblasts.
Antigenicity of freeze‐dried bone aIlograft in periodontal osseous defects
Authors: Turner Donald W. , Mellonig James T.
Published: July 2006

Freeze‐dried bone allografts have been used in the treatment of periodontal defects for almost a decade. The present study was undertaken to compare the immunogenicity of freeze‐dried cortical bone allografts with fresh cancellous bone and marrow allografts.

Cortical bone from a donor baboon was deep frozen and then freeze‐dried. Cancel lous bone and marrow was removed from the same donor.

Angular periodontal osseous defects in the jaws of 2 recipient baboons received freeze‐dried osseous allografts and a third animal received fresh marrow allografts. Three months later the animals received a second identical osseous graft in the arch diagonally opposite the first recipient site.

Prior to placing the first grafts and 3 weeks after the second graft was in place 51Cr release assays were done for cytotoxic antibody and cytotoxic lymphocytes to determine if the osseous allograft materials induced immune responses on the part of the recipient animals.

After the second grafts were in place for 3 weeks, the serum and lymphocytes of the animal grafted with allogeneic cancellous bone and marrow showed a higher degree of cytotoxicity for donor target cells than sera and cells from animals grafted with freeze‐dried material.

The results indicate that there was little or no immune response, as detected by the assays used, to freeze‐dried cortical bone allografts in comparison to fresh cancellous bone and marrow allografts.
The periodontal status of subjects receiving non‐steroidal anti‐inflammatory drugs
Authors: Waite I. M. , Saxton C. A. , Young A. , Wagg B. J. , Corbett M.
Published: July 2006

A test group of 22 subjects who had been taking non‐steroidal anti‐inflammatory drugs for periods in excess of one year were matched with a control group of 22 office workers with reference to age and Plaque Index. It was found that the test group had significantly lower values of Gingival Index and shallower depths of pockets than the control group of subjects. There was a trend also for there to be less loss of attachment in the test group. These results were interpreted as indicating that anti‐inflammatory drugs may influence the response of the periodontal tissues to plaque by reducing the prostaglandin concentration in the tissues. The slight decrease in loss of attachment in the test group may also be explained by the reduction in prostaglandin synthesis in the subjects taking anti‐inflammatory drugs.
Connective tissue regeneration to periodontally diseased teeth
Authors: Steiner Shaunda S. , Crigger Max , Egelberg Jan
Published: July 2006

The possibility of obtaining new connective tissue attachment to periodontally diseased root surfaces following replaced flap procedure was studied in seven single‐rooted teeth from six patients with advanced chronic periodontilis. Mucoperiosteal flaps were raised and supraosseous soft tissues curetted from the lesion. In order to establish a landmark for histological observations located within the periodontal pocket, a notch was made into the root just apical to existing subgingival calculus. A similarly placed notch was used in a previous report (Cole et al. 1980). Following thorough root planing, the flap was replaced and sutured. Four months later block biopsies were removed. The results demonstrated that none of the specimens showed soft connective tissue adhering to the tooth or evidence of new cementum coronal to the notch. A thin junctional epithelium had proliferated to the level of, or beyond the notch. Therefore, among these seven specimens, unequivocal proof of new attachment to diseased root surfaces following conventional full thickness flap procedures was not demonstrated. This is in contrast to the previous report (Cole et al. 1980) wherein new attachment was obtained in all of 10 specimens treated by full thickness flap surgery supplemented with citric acid conditioning of the root surface.
Fine structure of new connective tissue attachment following acid treatment of experimental furcation pockets in dogs
Authors: Selvig K. A. , Ririe C. M. , Nilvéus R. , Egelberg J.
Published: July 2006

Periodontal furcation pockets were created in mandibular premolar teeth of three beagles and subsequently treated by reconstructive procedures including flap surgery, root planing and application of citric acid. Block biopsies removed after 1, 2, 3 and 6 weeks showed new attachment of connective tissue to the periodontally involved root surface. This was established by progressive interdigitation of new collagen fibrils and the acid‐exposed fibrils of the dentin matrix along the root planed surface as well as within the orifice of dentinal tubules. The results supplement those of a previous study (Ririe, Crigger & Selvig 1980) and show that attachment of soft connective tissue to a root planed and acid‐conditioned dentin surface can be achieved by the same mechanism irrespective of whether the root surface has been surgically denuded or has been exposed to the environment of an experimental periodontal pocket.
Development of the dento‐gingival junction of the free gingival graft
Authors: Freeman Eric
Published: July 2006

Although numerous histological studies have been reported on the healing of the free gingival graft, little attention has been paid to the development of its relationship to the tooth. This is surprising as the placement of a graft of keratinized tissue against the tooth might be supposed to form a more effective barrier to the antigens of dental plaque. The purpose of this study was to investigate the histology of the dento‐gingival junction formed from free gingival grafts. Autografts of palatal mucosa were secured coronal to the crest of the alveolar process at six recipient sites on each of four adult cynomolgus male monkeys. All procedures were carried out sequentially so as to yield postoperative specimens of 1, 2, 3, 4, 5 & 6 weeks.

At sacrifice all animals were perfused with 10% formalin and the specimens were prepared by routine histological methods for examination by light microscopy. By two weeks the epithelium had migrated to the tooth surface. It exhibited wide intercellular spaces and was supported by a disturbed connective tissue. By four weeks the inflammation in the connective tissue at the facial aspects of the graft had resolved and the epithelium keratinized; while at the tooth surface, the connective tissue remained inflamed and the dento‐gingival junction developed over this disturbed tissue. The sulcular epithelium was not keratinized and the junctional epilhelium demonstrated wide intercellular spaces. Since the dento‐gingival junction developed from a free gingival graft does not seem to provide a more effective barrier to the antigens of dental plaque than that normally found, it is suggested that the use of the free gingival graft in some periodontal procedures be seriously questioned.