bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long term effect of chlorhexidine on developing gingivitis in the Beagle dog
Authors: Hamp Sven‐Erik , Lindhe Jan , Löe Harald 
Published: July 2006

Twenty Beagle dogs, ten in an experimental group and ten controls, were given a soft plaque forming diet for 12 months. A .2 per cent aquous solution of chlorhexidine gluconate was applied twice daily to the teeth and gingivae of the experimental animals. The dogs of the control group were similarly treated with saline. Assessments of plaque, calculus and gingivitis were performed after 7, 14, 21, 28 days and 2, 4, 6, 8, 12 months. Gingival exudate was also measured.During a period of six months topical application of .2 per cent chlorhexidine essentially prevented plaque, calculus and gingivitis development, while control dogs exhibited large amounts of dental deposits and marked clinical signs of chronic gingivitis. After six months, however, plaque and gingivitis appeared also in the chlorhexidine group. At the termination of the experiment. Gingival Index and exudate scores of the chlorhexidine group had reached approximately half the values of the saline group. No clinical side effects but the occurrence of stain on teeth was registered during the entire experiment.
Evidence of alveolar bone loss in rats fed an atherogenic diet
Authors: Plenk H. , Rudas B. , Waechter R. 
Published: July 2006

Normal Wistar rats, aged four and six month, were fed an atherogenic diet and the resulting periodontal changes were determined after six and eight weeks using histological, histochemical and histometrical methods. The changes of the alveolar bone remodelling adjacent to incisor teeth were compared with those around molar teeth.A diminished formation of new bone and an increased osteoclastic resorption were found in the alveolar bone of the rats fed the atherogenic diet. In addition gingival inflammation and the development of periodontal pockets were observed.Using histometrical evaluation it could be demonstrated that these alveolar bone changes were significantly more pronounced in the incisor teeth than in the molars. It is supposed that the latter finding is due to the more intense remodelling of the alveolar bone in the constantly growing teeth of rodents.
A comparative study of the surface of keratinized and non‐keratinized oral epithelia
Authors: Cleaton‐Jones P. , Fleisch L. 
Published: July 2006

Portions of clinically healthy epithelium from the hard and soft palates, free and attached gingivae, cheek, floor of mouth and lip from the vervet monkey (Cercopithecus aethiops) were examined with the light and with the scanning electron microscope.The epithelia can be subdivided histolocally into keratinized and non‐keratinized types. Each of these has a definite surface appearance irrespective of the region from which they are derived. Non‐keratinized epithelia show a corrugated surface formed by microplications while keratinized epithelia have a cratered or pitted appearance. In addition, the parakeratinized free gingival surface may be masked by the presence of pellicle. The reason for the different surface appearances is obscure but may be related to different intercellular interdigitations in the two types of epithelia.
Influence of temporomandibular joint receptors on tactile occlusal perception
Authors: Caffesse Raul G. , Carraro JuanJ. , Albano Enrique A. 
Published: July 2006

Previous studies have shown that tactile occlusal perception is not eliminated when teeth are anesthetized. Based on the suggestion that such perception could be influenced by other receptors in the masticatory system, the possible role of the temporomandibular joint receptors was considered in this study.The minimal thickness (in units of 8 microns) detected between opposing teeth initially and after anesthesia of both temporomandibular joint capsules, was determined in 15 subjects. Results showed a mean difference for the group of 2·0 units with a standard error of 0.54 which was highly significant (p < 0·001). However, 40% of the subjects did not show any variation after anesthesia.It is concluded that receptors from the temporomandibular joint capsule may play an important role in determining the tactile occlusal perception.
Some antibacterial properties of chlorhexidine
Authors: Hennessey T. D. 
Published: June 2006

The use of the antiseptic chlorhexidine as a therapeutic or prophylactic drug in dental or periodontal hygiene is a departure from the usual fields of use for this agent. Therefore, a review of some of its antibacterial properties is desirable.The bacteriostatic spectrum of chlorhexidine * was determined: there was a wide spectrum of activity with gram‐positive cocci being especially sensitive (MIC 0.19 to 2.0 μg/ml). Exposure of suspensions of various bacterial species to chlorhexidine (0.02%) for 10 minutes at room temperature, reduced the viable organisms by about 99.99% in most instances. Addition of serum to the test system reduced the bactericidal action markedly. A study with Streptococcus mutans revealed that the presence of sucrose (5%) in the growth‐medium used for preparing bacterial suspensions, profoundly influenced the bactericidal activity. This is presumed to be the result off adsorption of chlorhexidine to extracellular polysaccharides.Attempts to select Escherichia coli and oral streptococci resistant to chlorhexidine by serial passage in subinhibitory concentrations in vitro, indicated that mutants were rare. In contrast, mutants of E. coli resistant to ampicillin or streptomycin were selected with ease. Predictions of what might happen under clinical conditions (where oral organisms might be exposed to sublethal concentrations for very long periods of time) cannot be made from such laboratory experiments. No changes were observed in the susceptibility of faecal organisms of hamsters given chlorhexidine (50 mg/kg) daily by gastric catheter for 28 days but 100 mg/kg rapidly caused a lethal enteritis which was assumed to be the result of gross disturbances of the alimentary microflora.A small study in three human volunteers is reported. Use of a mouthrinse (twice a day for up to seven weeks) containing chlorhexidine digluconate (0.2%) resulted in a slight but transient change in susceptibility of salivary organisms to the bacteriostatic action of the agent. Whether resistance will prove to be an obstacle to the use of chlorhexidine in prophylaxis, in the mouth can be decided only with more clinical experience.
Oral leukocytes and gingivitis in the primary dentition
Authors: Cox M. O. , Crawford J. J. , Lundblad R. L. , McFall W. T. 
Published: July 2006

A survey was performed to evaluate the relationships among orogranulocytic migratory rale, gingival index and plaque index in a group of systematically healthy preschool children.The fifty children selected for study had only primary teeth, no pharyngeal or extragingival inflammation and were taking no medication. Each child was subjectively scored for the amount of bacterial plaque and gingival inflammation present. The rate of migration of leukocytes into the oral cavity per 30 second period was determined from the last three of ten 30 second consecutive oral saliva rinses as an objective measure of gingival inflammation.A minimal amount of localized mild marginal gingivitis was observed in the presence of a rather large plaque accumulation. No significant correlation was observed between rates of oral leukocyte migration and the degree of gingival inflammation. However, the leukocyte migratory rates in this group were quite low as compared to those found in adults by other investigators.
Effect of anti‐thymocyte serum on chronic gingival inflammation in dogs
Authors: Nobréus Nils , Attström Rolf , Egelberg Jan 
Published: June 2006

The role of cellular immunity in chronic gingivitis has been studied in beagle dogs. The mechanism of delayed hypersensitivity in the animals was suppressed by administration of rabbit anti‐dog‐thymocyte globulin (ATS). The immunosuppressive effect of the antiserum was evaluated from the inhibition of a delayed hypersensitivity reaction in the skin to l‐dinitro‐2.4‐chlorobenzene (DNCB). The level of gingival inflammation was determined before and after antiserum administration by measurements of crevicular leukocytes, gingival fluid and activity of acid phosphatase in crevicular samples.Antiserum administration inhibited the hypersensitivity reactions in the skin towards DNCB. The gingival parameters were moderately reduced, but similar changes occurred in a group of control dogs injected with normal rabbit immunoglobulin. The results indicate that cellular immunity does not play a major role for the continuous maintenance of chronic gingivitis in the beagle dog.
A histochemical study of glycosidases in hydantoin induced hyperplastic, healthy and inflamed human gingiva
Authors: Larmas Liisi 
Published: July 2006

Fresh samples of hydantoin induced hyperplastic, healthy and inflamed human gingiva were studied histochemically using various azo dyes for β‐glucuronidase (EC 3.2.1.31), for β‐ and β‐glucosidase (EC 3.2.1.20 and 3.2.1.21) as well as β‐galactosidase (EC 3.2.1.23) and for N‐acetylglucosaminidase (EC 3.2.1.30), in order to add support to the hypothesis that hydantoin induced hyperplasia is always connected with inflammation.Moderate β‐glucuronidase activity was observed in healthy, inflamed and hydantoinhyperplastic gingiva. The distribution of the enzyme activity was similar in all types of the tissue except the stratum corneum. The healthy gingiva did not reveal this activity whereas the inflamed and hydantoinhyperplastic gingiva did. The stratum basale and spinosum of the epithelium, the fibroblasts and the inflammatory cells, especially the macrophages, revealed enzyme activity in all types of tissues. In the healthy tissue only a few inflammatory cells were seen and thus the β‐glucuronidase activity was low when compared to inflamed or hyperplastic gingiva.Weak β‐galactosidase, N‐asetylglucosaminidase and β‐glucosidase activity was seen in all types of gingival samples. Enzyme activity was observed in the same structures as β‐glucuronidase with the exception of the stratum corneum, which revealed no activity.The relatively strong β‐glucuronidase activity in the keratinized cell layer of the epithelium of inflamed and hydantoinhyperplastic tissue may be due to the microbial enzyme diffusion into the keratinized cell layer of the injured tissue.
The effect of various disclosants on plaque accumulation in human subjects
Authors: Goldman R. S. , Abelson D. C. , Mandel I. D. , Chilton N. W. 
Published: July 2006

A clinical trial was designed to evaluate the effect of daily use of three disclosants, erythrosine, fast green and sodium fluorescein, compared to a saline control, on subsequent plaque deposition. Twenty subjects refrained from all oral hygiene for four consecutive 7 day periods. Each subject rinsed each night with a disclosing solution or saline as assigned and according to a design using 5 restricted Latin Squares of 4 subjects each.At 7 day intervals, plaque score (modified Quigley‐Hein, J. Periodontology, 41:41, 1970), plaque weight and absorbance were evaluated and each subject received a rubber cup prophylaxis and another disclosant was assigned. The data revealed no significant differences between the groups of subjects using the various disclosants or saline, demonstrating that daily use of these agents has no effect on rates of plaque formation as determined clinically. There was a statistically significant increase in plaque accumulation (20 %) in all groups by completion of the experiment despite the weekly prophylaxis. All subjects had a moderate to severe gingivitis by the end of the fourth week.
Restricted latin square design in a plaque disclosant study
Authors: Varma A. A. O. , Fertig J. W. , Chilton N. W. , Mandel I. D. 
Published: July 2006

Twenty subjects were used in a clinical trial of the effect of 3 disclosants (erythrosine, fast green, sodium fluorescein and normal saline) on plaque score, plaque weight and EDTA dispersion. Five 4×4 Latin Squares of a restricted type were employed, so that carryover effects can be estimated most efficiently. Each of the 20 subjects used each of the 4 test agents for a week at a time. The details of the design and of the statistical analysis are presented.There were no significant carryover effects for any of the study solutions on plaque score, plaque weight or EDTA dispersion. The 4 disclosants did not differ significantly from each other in their effect on the 3 variables. In the case of plaque score, the fourth week gave significantly higher average values than the first three weeks. In the case of plaque weight, the values in the first week were significantly elevated.The correlation coefficients between the 3 indices of plaque accumulation were only modest in size. The relatively low correlation between the 3 variables suggest that in a clinical trial the results with the 3 variables will not necessarily confirm each other.
Elevation of a serum component in periodontal disease capable of modulating chemotactic infiltration
Authors: Gothier Douglas E. , Richard Gaumer H. , Pihlstrom Bruce L. , Folke Lars E. A. 
Published: July 2006

Serum from dental patients was examined for its capacity to affect migration of polymorphonuclear leukocytes toward a complement‐independent chemotactic factor, bacterial filtrate of Escherichia coli, (BF), Seven subjects with advanced periodontitis, documented with clinical measurements of pocket depth, loss of attachment, indices for gingival inflammation and oral hygiene, were paired with normal subjects of similar age and sex.This study shows that patients whose only apparent clinical symptom was severe periodontal inflammation harbor a heat‐stable, serum component which neutralizes factors chemotactic for polymorphonuclear leukocytes. A role for this component in modulation of inflammatory infiltration is discussed.
The collagen content of skin and gingival tissues in ascorbic acid‐deficient monkeys
Authors: ØSstergaard E. , Löe Harald 
Published: July 2006

Five green monkeys were used In this study. Three animals were fed a scorbutigenic diet and the remaining two served as controls. Biopsies were dissected from the vestibular gingiva and dorsal skin and polyvinyl sponges were implanted subcutaneously during 4 week periods throughout the experimental period. The animals were sacrificed after 12 weeks and the periodontal ligament was removed. Collagen extracts were prepared from the gingival and granulation tissues and treated with bacterial collagenase. Following acid hydrolysis the total amount of proline and hydroxyproline was determined in the various tissue preparations.In the tissues examined, the content of hydroxyproline decreased in the scorbutic animals throughout the experimental period. The decrease in the hydroxyproline content of the gingiva started within the first 4 weeks and was faster than that of the skin, indicating that the extent of decrease is dependent of the turnover rate of the collagen in the tissues. The synthesis of hydroxyproline was almost totally impaired in the granulation tissue formed in the sponges implanted after the 8th week of experimentation. Collagenase treatment of collagen extracts resulted in a release of proline and hydroxyproline in a higher ratio in extracts from the experimental animals than in extracts from the controls. It is concluded that ascorbic acid is a prerequisite for the maintenance of the collagen pool in the tissues and that lack of this vitamin results in the formation of a collagenase degradable protein fraction with a low hydroxyproline content.
Immunoradiometric assay for quantification of serum antibodies to dental plaque antigen in immunized dogs
Authors: Ahlstedt Staffan , Rylander Harald 
Published: July 2006

An immunoradiometric assay (IRMA) was used for quantifying dog serum antibodies to antigens from dental plaque collected from full‐grown dogs. The antigens were adsorbed onto the inner surface of plastic tubes and then incubated with dog‐anti‐plaque serum. 125I‐labelled anti‐dog plasma‐immunoglobulin was used for quantification of the specific antibodies.Four 10 months old Beagle dogs in excellent gingival health were immunized for 10 weeks with ultrasonicated dog dental plaque. The anibody levels in antisera sampled 6, 8, 10 and 11 weeks after the first antigen injection were 2 to 5 times as high as those recorded before the immunizing period.The variability of the assay as judged from the difference between duplicate samples was found to be 18 %± 4 (p < 0.01) of the mean value and the variability between the same serum ran on different test occasions 13 %± 7 (p < 0.01). The specificity of the antigen‐antibody reaction in the immuno assay was tested by inhibition experiments, Preincubation of the antisera with dental plaque antigen significantly inhibited the antigen‐antibody reaction in the IRMA, while bovine serum albumin did not.
Plaque induced periodontal disease in beagle dogs
Authors: Lindhe Jan , Hamp Sven‐Erik , Löe Harald 
Published: July 2006

The present investigation was carried out in order to study some aspects of the clinical, roentgenographical and histopathological alterations of periodontal tissues in dogs which during a 4‐year period were allowed freely to accumulate plaque.Twenty inbred Beagle dogs, at the start of the study 10 months of age, were used. During a preparatory period of eight weeks the animals were once weekly subjected to a careful prophylaxis and had their teeth brushed twice daily. At the end of this period the dogs were divided into two groups of ten (test and control). From day zero of experimentation and onwards the teeth of the control dogs were twice daily subjected to meticulous toothbrushing, whereas the teeth of the test dogs were not cleaned. Examinations of the periodontal tissues were performed at days 0, 7, 14, 21, 28 and after 2, 4, 6, 8, 12, 18, 24, 36 and 48 months. Biopsies of different tooth regions were made on day zero and after 6, 12, 18, 24, 36 and 48 months of experiment. In the sections were measured (i) the distance from the cemento‐enamel junction (CEJ) to the most apical cells of the dento‐gingival epithelium, and (ii) the distance from CEJ to the level of the marginal alveolar bone.The study demonstrated that it is possible in dogs to establish and maintain a normal gingiva simply by eliminating calculus and then subjecting the animals to daily repeated and carefully performed tooth cleanings. Dogs allowed freely to accumulate plaque rapidly developed signs of gingivitis and eventually also clinical, radiographical and histopathological signs of periodontal tissue breakdown. The observations show that at least one type of periodontal disease is induced by factors within the dental plaque.
Total viable count and differential count of vibrio (campylobacter) sputorum, fusobacterium nucleatum, selenomonas sputigena, bacteroides ochraceus and veillonella in the inflamed and non inflamed human gingival crevice
Authors: Van Palenstein Helderman W. H. 
Published: July 2006

From 3 groups of individuals with non inflamed, slightly inflamed or moderately inflamed gingiva 3 to 4 paperpoint samples were taken from different buccal gingival crevices in each individual.Samples were cultivated on a modified CBRCA medium which permitted the differential count of five groups of gram‐negative anaerobes. The total count per volume units was 9‐times higher in moderately inflamed than in non inflamed crevices. A significant increase in the proportion of Vibrio (Campylobacter) sputorum and Fusobacterium nucleatum occurred with inceasing gingival index score. Bacteroides ochraceus and Selenomonas sputigena, though present in low numbers also increased slightly. The proportion of Veillonella seemed independent of gingival index score. This added up to a significant increase in the proportion of cultivable gram‐negative organisms with increasing gingival index score.
The relationship of manual dexterity and knowledge to performance of oral hygiene
Authors: Kenney E. B. , Saxe S. R. , Lenox J. A. , Cooper T. M. , Caudill J. S. , Collins A. R. , Kaplan A. 
Published: July 2006

The correlations between manual dexterity test scores and oral hygiene scores and the correlations between the level of oral hygiene knowledge and oral hygiene scores were investigated in 59 students. Oral hygiene was measured by a modified Löe and Silness plaque index. The buccal and lingual plaque scores were considered together as were the mesial and distal scores. Dexterity was measured by a peg board test and oral hygiene knowledge was measured by a 15 question multiple choice test. Each subject was shown two audiovisual programs on oral hygiene. Plaque scores were measured at the beginning of the study, at 7 days (immediately after carrying out oral hygiene) and at 14 days.Manual dexterity of the right or preferred hand showed significant statistical correlations with all oral hygiene scores except the 14 day interproximal score. There was no significant correlation between left or nonpreferred hand on any of the plaque scores.A correlation was seen between knowledge of oral hygiene (as measured by the multiple choice test) and several of the oral hygiene scores. These correlations were less significant than that seen between dexterity and oral hygiene.
Collagen turnover in the periodontal ligament under normal and altered functional forces
Authors: Rippin J. W. 
Published: July 2006

Left maxillary molar teeth were extracted from twenty‐four six‐week old rats, and two weeks later they and twenty‐four control animals were given 1μCi/gm of body weight of tritiated proline by intraperitoneal injection; four animals from each group were killed after a further 12 hours, 1, 2, 4, 7 or 12 days. Following autoradiography, grain densities were determined in crestal, mid‐root and apical areas of the periodontal ligament, and regression lines of log grain density on time after H3‐proline administration calculated.Half‐lives derived from the linear regression lines were attributable to collagen turn‐over and varied from 2.45 days in all apical areas to 6.42 days in the crestal areas of opposed teeth. This high turnover rate seemed to occur throughout the whole width of the ligament allowing the tissue remodelling associated with tooth movement. Over‐eruption of the unopposed teeth resulted in a half‐life of 5.25 days in the crestal area, suggesting that turnover rate depends partly on the amount of tooth movement required.
A mechanistic analysis of gingival fluid production
Authors: Pashley DavidH. 
Published: July 2006

A mechanistic evaluation of gingival fluid is presented in an effort to identify the important physiologic variables that must be measured before one can define the exact mechanism(s) of gingival fluid production. This approach evaluates the Starling factors governing fluid distribution across capillaries by modifying these concepts to fit the unique structures, environment, and functional demands of tissues in and around the gingival sulcus. Many assumptions are made to simplify arguments and to approximate unknowns. Suggestions are made regarding techniques and experimental methods that might be employed to evaluate several important variables.Gingival fluid production is viewed as the result of an increased rate of capillary transudation brought about by the release of mediators of inflammation. These agents are thought to cause both increased capillary pressure and increased leakage of plasma proteins into the interstitial fluid. It is postulated that the low compliance of gingival tissue and the high hydraulic conductance of sulcular epithelium result in this interstitial fluid moving from connective tissue into the sulcus.