bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
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.
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.
Peripheral blood leucocytes with receptors for extracts of dental plaque
Authors: Walker D. M. , Hardy G. 
Published: July 2006

The percentage of peripheral blood leucocytes with receptors for dental plaque has been determined with a rosetting assay. Patients with periodontal disease had a significantly greater mean fraction of leucocytes with receptors for a plaque extract than could be detected in leucocytes from healthy subjects. The percentage of plaque binding leucocytes was dependent upon the plaque concentrations used to coat the indicator sheep erythrocytes.Attempts to demonstrate the receptors directly by pre‐incubation of the leucocytes with high concentrations of plaque were unsuccessful in that subsequent rosette formation with plaque coated sheep erythrocytes was not inhibited.It is suggested that both antigen binding cells and mitogen binding cells are detected by the present method in proportions dependent upon the plaque concentration employed.If tolerance occurs to plaque in advanced periodontal disease, it is not due to a reduction in the number of specific antigen binding cells.
Bone resorbing activity of gingiva from beagle dogs following metronidazole and indomethacin therapy
Authors: Nuki K. , Soskolne W. A. , Raisz L. G. , Kornman K.S. , Alander C. 
Published: July 2006

Twenty‐four beagle dogs were divided into three groups of eight dogs each. Periodontitis was induced in three of the denial quadrants of each dog using wire ligatures while one quadrant was not ligaled and was kept cleaned. One group of dogs received no additional treatment, one group received systemic metronidazole and the third group received systemic indomethacin. The in vitro bone resorbing activity of extracts from freeze dried gingiva from the groups was compared.Extracts of gingiva from ligaled teeth produced significant bone resorption. Metronidazole treatment suppressed this ligature‐induced bone resorbing activity while indomethacin had no effect. Extracts from gingiva from around clean non‐ligated teeth had somewhat less activity than extracts from gingiva of ligaled teeth, although some significant resorption remained in all treatment groups. Bacterial cultures from melronidazoletreated groups showed a change from a predominantly Gram negative obligatory anerobic flora (B. assacharolyticus), to one predominated by Gram negative, facultative anaerobes (Capnocytophaga and Campylobacter). It was concluded that metronidazole suppressed bone resorbing activity by inducing a change in the flora of the gingival crevice.
The predominant cultivable subgingival flora of beagle dogs following ligature placement and metronidazole therapy
Authors: Kornman K. S. , Siegrlst B. , Soskolne W. A. , Nukl K. 
Published: July 2006

Ligature‐induced periodontitis was evaluated microbiologically in 8 beagle dogs. Gingival health was established by repeated cleaning. At day 0 subgingival plaque was sampled from individual sites in two quadrants. All teeth in one quadrant were then ligated at the CEJ, and the other quadrant served as a non‐ligated control which was cleaned three times each week. At day 14, four dogs were given metronidazole for seven days. Plaque was cultured anaerobically on nonselcctive media, and the predominant cultivable flora was characterized. At day 0 Gram‐negative facultative rods represented 56.8 % of the flora. with motile and surface translocating organisms predominating. At day 14 Bacteroides asaccharolyticus, including catalase positive B.asaccharolyticus‐like organisms, increased at ligated sites to 34.7 % of the cultivable flora. After metronidazole therapy the total bacterial count decreased, and Gram‐negative anaerobic rods became non‐detectable. Gram negative facultative bacteria which were motile or surface translocating represented 52.7 % of the cultivable flora after metronidazole treatment.In the beagle dog ligature placement was associated with a shift in the flora from Gram‐negative facultative rods to Gram‐negative anaerobic rods. Metronidazole treatment reduced the total cultivable flora and selectively reversed the microflora shifts which followed ligature placement.
The microbiology of ligature‐induced periodontitis in the cynomolgus monkey
Authors: Kornman K. S. , Holt S. C. , Robertson P. B. 
Published: July 2006

The cultivable subgingival microflora in the cynomolgus monkey, Macaca fascicularis, was monitored during the ligature‐induced progression of naturally occurring gingivitis to periodontitis. Clinical and microbiological observations were divided into four stages. Stage I, prior to ligature placement, was characterized clinically by chronic generalized gingivitis and microbiologically by Gram‐positive cocci and rods with B. melaninogenicus ss. intermedius the dominant Gram‐negative organism. Stage II, 1 to 3 weeks following ligature placement, exhibited slightly greater gingival inflammation but no clinical evidence of attachment loss. The subgingival flora showed a significant increase in motile and surface translocating Gram‐negative rods, primarily Capnocytophaga species and Campylobacter sputorum. Stage III, 4 to 7 weeks following ligature placement, revealed increased pocket depth and radiographic evidence of alveolar bone loss. This stage was characterized by a Gram‐negative anaerobic flora with B. asaccharolyticus as the dominant cultivable organism. Stage IV encompassed the remainder of the experimental period, 8 to 17 weeks, during which time no further change in the clinical parameters occurred and levels of B. asaccharolyticus decreased.The subgingival microflora of ligature induced periodontitis in Macaca fascicularis closely resembled that reported for human periodontal disease and the episodic clinical pattern of attachment loss was associated with levels of Gram‐negative anaerobes, primarily B. asaccharolyticus.
Mucopolysaccharide localization in gingival epithelium
Authors: Wiebkin Ole W. , Thonard John C. 
Published: July 2006

Short incubations, at 37°C, of small freshly excised pieces of healthy human gingivae iancorporated [35S]‐sulphate and [3H]‐acetate into macromolecular material which could be precipitated intercellularly in the epithelium. Following radioactively pulse‐chased incubations, such localization was observed by autoradiography on cryostat histological sections fixed in cetylpyridinium chloride. Critical electrolyte salt concentration elution indicated that most of the intercellular material was soluble in 0.63M‐MgCl2, and any material which remained was intracellular. In vitro and in vivo incorporation studies were compared. These data corroborate biochemical studies (Wiebkin, Bartold & Thonard 1979) together with other histochemical observations that proteoglycans (mucopolysaccharides) are a major intercellular component of human gingival epithelium. Molecular conformation and the relatively rapid synthesis and secretion rate for this class of epithelial macromolecule may explain the lack of susceptibility of this material in the intercellular site, both to degradation by some specific enzymes previously reported and to elution with critical salt concentrations from cationic detergent precipitates.The method described, together with in vivo incorporation studies, provides a useful technique for studying direct effects of some microenvironmental influences on gingival epithelium.
Tetracycline treatment of periodontal disease in the beagle dog
Authors: Williams R. C. , Leone C. W. , Jeffcoat M. K. , Scott E. R. , Goldhaber P. 
Published: July 2006

Seventeen adult beagle dogs with moderate to severe periodontitis were examined at time zero and after a 6 month pretreatment period for plaque accumulation, gingival inflammation, and rate of alveolar bone loss. The dogs were then divided into three groups. One group was the untreated controls, one group received tetracycline HCl 250 mg daily, and one group received tetracycline HCl 500 mg daily. Plaque accumulation, gingival inflammation, and rate of alveolar bone loss in each group over a 12 month treatment period was compared to the pretreatment baseline values in each group.There was no significant difference in either the mean plaque accumulation or gingival inflammation over the 12 month treatment period in the untreated control dogs or the tetracycline treated dogs. The untreated control dogs lost alveolar bone in the treatment period at a rate similar to the pretreatment period. In the dogs treated with 250 and with 500 mg tetracycline HCl there was a statistically significant decrease in the rate of alveolar bone loss in the treatment period when compared to the pretreatment period.The findings suggest that daily tetracycline in either a 250 or 500 mg dose does not affect accumulation of bacterial plaque or severity of gingival inflammation in the beagle dogs studied. Tetracycline administration does significantly decrease the rate of alveolar bone loss in the treated animals for a 12 month period. An additional report will detail the subsequent 12 months of treatment in which tetracycline loses its ability to reduce the rate of alveolar bone loss.