bluuebunny/crossref_metadata_2025 huggingface dataset:
An enzyme histochemical study of adenosinetriphosphatase (ATPase) activity during molar eruption in the mouse
Authors: Heyden Guy
Published: July 2006

The distribution of blood vessels during molar eruption in the mouse was disclosed by means of their histochemical reactions for ATPase activity, using the reversible inhibition test of Padykula and Herman (1955), at pH 9.4, after EDTA‐decalcification of the specimens. A rich vascular supply was registered between the epithelial protrusions lateral and occlusal to the crowns, in the stellate reticulum and lining the external dental epithelium. Large vessels were found in the narrow connective tissue regions above the erupting lingual cusps. No joining proliferation of the oral and dental epithelia was observed before their fusion. A significant ATPase activity seemed to accompany an extensive vascularization, an increased keratinization, and a possible induction for oral epithelial proliferation and migration.
Quantitative Determination of immunologlobuline (IgG, IgA and IgM) and identification of IgA‐type in the gingival fluid.
Authors: Holmberg Kenneth , Killander Johan
Published: July 2006

Quantitative immunoglobulin determinations were performed by a single radial imrmmo‐diffusion method with verified specificity and precision. The identification of sernm‐IgA or secretory‐IgA in gingival fluid was carried out in double diffusion in gel experiments with the use of a specific anti‐serum to “secretory piece”. Gingival fluid was collected with micropipettes by capillarity from subjects with different degrees of gingival inflammation. Blood and mixed saliva were sampled from each individual at the same time. In accordance with previous studies the gingival fluid occured after irritation of the gingival tissue. The amount of the gingival fluid increased with the severity of the inflammation. The contents of the different immumoglobulins in gingival fluid conformed to those, in serum. The possible reason of a slight tendency to lower contents of IgA and IgM in gingival fluid compared to those in serum in subjects with chronically inflamed gingivae is discussed. No “secretory piece” was demonstrated in any samples of gingival fluid tested at different dilutions. The immunoglobulin A in gingival fluid was indicated to be of serum‐IgA‐type. The origin of the immunoglobulins in gingival fluid is discussed.
Cell‐mediated immunity and humoral antibodies in acute ulcerative gingivitis
Authors: Wilton J. M. A. , Ivanyi L. , Lehner T.
Published: July 2006

Humoral antibodies and cell‐mediated immunity in patients with acute ulcerative gingivitis were investigated using antigens from Odontomyces(Actinomyces) viscosus, Fusobacterium fusiforme, Veillotiella alcalescens and Bacteroides melaninogenicus. There were no differences in serum antibody levels between patients and control subjects on the first day of attendance and up to one month after the disease started. Serum and salivary IgA estimations failed to show a significant difference between patients and controls. Cell‐mediated immunity measured by the lymphocyte transformation test, yielded significantly different results between patients and controls. An immune pathogenesis for acute ulcerative gingivitis has been postulated to account for the immunological findings.
In vitro experiments on gingival exudate mesurements
Authors: Leirskar Jakob
Published: July 2006

A laboratory technique for measuring the mobility of solution on filter paper has been presented. Various exudates exhibited different mobilities on filter paper; this also applied to exudates of the Same origin (Pleura punctates.) When diluted, the exudates exhibited increased mobility, indicating that the concentrations of various exudate components were of importance. The addition of cells (5 × 106 and 25 × 106 P 388 D cells/ml exudate) did not significantly change the mobility, whereas the mobility of protein fractions (human albumin and gamma globulin) was inversely related to the concentration of the solutons.

These finding may be of significance to the reliability of present methods used for the quantitation of gingival exudation.
A biophysical approach to the adhesion of human gingival epithelial cells to tooth and glass surfaces
Authors: Weiss L. , Neiders Mirdza E.
Published: July 2006

Isolated gingival cells and tooth particles carry a net negative charge as determined by particle electrophoresis in RPMI1630 medium with 10% calf serum. By use of colloid theory, computations of the average interaction forces between epithelial cells of human gingjva and tooth and glass surfaces were made, using the experimentally determined electrokinetic data.

An experimental check for our computations was made by attempting to centrifuge cells through the computed “barriers” due to repulsion forces, which were equivalent to 1800 g for spherical cells. Relative centrifugal forces of 3,000 g were insufficient to bring the cells into close contact with glass or enamel surfaces, indicating that the computations underestimated the repulsive interactions between the cells and various surfaces, and that cells must exhibit some “escape” mechanism to adhere to these surfaces.

The relevance of the in vitro system to the in vivo situation was discussed.
Gingival tissue physiology in vitro
Authors: Powell R. N.
Published: July 2006

Sixty gingival explants were cultured in vitro for periods of one to forty‐eight hours in media containing I μc/ml tritiated thymidine. Autoradiograptas revealed a pattern of labelling dependent on the method of excision of the explants. Where epithelial ridges were intact, proliferalive activity at the lateral margins of the explants preceded the migration of the epithelium. Where ridges were incised during removal of the explant the injured ridges also contributed extensively to the proliferation of cells which then began active migration. Labelling of cells in the newly migrated epithelium occurred after the appearance of an argyrophilic hasement membrane byt before the appearance of a P.A.S, positive structure.
Historical quantification of the biological effects of estradiol benzoate on the gingiva and gential mucosa of castrated rabbits
Authors: Rlibright William C. , Higa Leslie H. , Yannone Michael E.
Published: July 2006

The biological effects of castration and estrogen replacement therapy were studied in the gingiva of adult female rabbits. Measurements were made to hislologically quantitate changes induced by estrogen on the gingiva when compared to the well established effects which occur in the reproductive tract of the female rabbit. Parentally administered esradiol benzoate resulted in significant changes within the uterus and vagina. No corresponding changes were detected in the gingiva.
Histometric evalution of periodontal bone loss in rats
Authors: Carranza F. A. , Simes R. J. , Mayo I. , Cabrini R. L.
Published: July 2006

The effect of marginal irritation, trauma from occlusion and total body X‐irradiation on interradicular bone of Wistar rat molars, was studied after an experimental period of two weeks. Histologic findings and slatistical evaluation of histometric results indicate that:

the only single factor capable of reducing the height of interradicular bone was marginal irritation,

the only additional factor that was capable of increasing this reduction in height was total body X‐irradiation,

marginal irritation, either alone or in combination with trauma from occlusion increased bone density in the submarginal areat

total body X‐irradiation inhibited the osteogenic reaction induced in the submarginal area by marginal irritation.

trauma from occlusion did not have any effect on the parameters measured.
Urea content of gingival crevicular fluid and its relation to periodonal disease in humans
Authors: Golub L. M. , Borden S. M. , Kleinberg I.
Published: July 2006

The present study has demonstrated that urea is present in gingival crevicular fluid and its concentration is usually several times higher than that of blood serum or saliva. This supports the hypothesis that the high pH seen in gingival crevices arises from urea. The concentration of crevicular urea was inversely related to the severity of gingival inflammation and increased markedly following periodontal surgery. It was concluded that clinically healthy or slightly inflamed gingivae have a mechanism for concentrating urea in crevicular fluid and that this mechanism is destroyed during inflammation but reconstituted following periodontal surgery.
The Ultrastructure of leukocyte emigration through the sulcular epithelium in the beagle dog
Authors: Garant P. R. , Mulvihill J. E.
Published: July 2006

An electron microscopic investigation of chronically inflamed beagle gingiva has been carried out in order to gain some insight into the pathogenesis of gingival destruction. Chronically inflamed sulcular epithelium was characterized by the presence of numerous polymorphonuclear neutrophilic leukocytes within the intercellular spaces. Many neutrophils were observed to have disrupted cell membranes with a consequent extrusion of cytoplasmic contents including lysosomal granules. The emigration of neutrophils through the epithelium was coincident with a marked decrease in epithelial cell‐to‐cell contacts such as desmosomes and tight junctions. In addition, the affected intercellular spaces were usually dilated and contained glycogen, granular precipitate and free lysosomal particles. The epithelial cells of inflamed sulcular epithelium contained altered tonofibrils. increased amounts of glycogen and accumulations of lipid droplets. It is suggested that the emigration of large numbers of neutrophils in response to chemotactic stimuli originating from the sulcus may damage the normal cell‐to‐cell relationship of the sulcular epithelium resulting in altered cell differentiation and widened intercellular spaces.
The Relationship between periodontal disease and blood groups and secretor status
Authors: Pradhan A. C. , Chawla T. N. , Samuel K. C. , Pradhan Mrs. S.
Published: July 2006

The purpose of present study was to determine the relationship between periodontal disease and blood groups with special reference to secretor status. 600 medical students constituted the study group and three sets of control were taken in parallel. First set was of 6000 blood donors for normal distribution of blood groups. Second set consisted of 200 cases selected on random basis from patients attending the Dental Out‐patient Department for blood groups and secretor status. Third set comprised of 100 cases with grade 0 periodontal involvement selected from the study group. The periodontal scoring was done in each case by Ramfjord's technique and the study group cases were divided into four grades ‐ 0, 1, II, and III. Blood grouping was done by slide and tube method and secretor status was tested by haemagglutination method of Weiner as modified by Roy and Chatterji. Statistically significant relationship was found between periodontal disease and blood groups but none with secretor status. This relationship points towards a possible genetic basis for etiopathogenesis of periodontal disease which should be explored further by conducting extensive studies.

It is a pleasure to acknowledge Dr. K. K. Kapoor, Reader, Division of Periodontics, Dental College and Hospital, Lucknow, for his valuable guidance and fruitful discussions in the planning and accomplishment of the present work. Our grateful appreciation is also due to Dr. Mrs. V. L. Lahiri, Reader in Pathology. G. S. V. M. Medical College. Kanpur, for her valuable suggestions and constructive criticism during the elaboration of the manuscript.
Longitudinal periodontometry
Authors: Green Edward , Clayton Joseph A. , Schork Michael A.
Published: July 2006

The O'Leary‐Rudd periodontometry system was modified to facilitate longitudinal studies of horizontal tooth mobility. Repeated measurements of the horizontal tooth mobility of tooth #27 and tooth #28 were accomplished in six patients to determine the accuracy and experimental error of the modified system. The mobility value of each tooth in all six patients was within the previously reported physiologic range of mobility values. The reproducibility or tolerance of the modified system was evaluated by calculating the coefficient of variation of the mobility measurements obtained from the repeated trials. The average coefficient of variation of the measurements within a patient was 11%. The average coefficient of variation of the measurements between the six patients was 10 %.
The role of inflammation in the pathogenesis of gingival enlargement during the administration of diphenylhydantoin sodium in cats
Authors: Nuki Klaus , Cooper Steven H.
Published: July 2006

In order to determine the role of gingival inflammation in the pathogenesis of the gingival enlargment seen in individuals taking diphenylhydantoin sodium (DPH), thirteen female and ten male adult mongrel cats were subjected to a coarse diet, irritating plastic bands around selected teeth, and a daily tooth brushing routine. Fourteen days after initiating the diet, bands, and brushing, 12 of the cats were randomly selected to receive a daily intramuscular injection, 10 mg/kg body weight, of DPH. The remaining cats received the equivalent amount of inert solvent.

The maxillary quadrants containing banded teeth were not brushed whilst the maxillary quadrants containing no banded teeth were brushed daily. This combination produced grossly inflamed (banded) and non‐inflamed (non‐banded) maxillary quadrants in two groups of animals; one group receiving DPH, the other receiving vehicle only. The mandibular gingiva were not used in this study.

It was possible to reproduce the clinical and histological appearance of DPH gingival enlargement in 11 of the 12 cats receiving DPH and whose gingiva were subjected to local irritation and no oral hygiene. Animals receiving DPH and oral hygiene care, but with no bands on adjacent teeth and thus no local irritation, showed no overt gingival enlargement.

Analysis of the results reveals that in the presence of local irritants, producing inflammation, gingival enlargement develops after DPH administration. In the absence of irritants no enlargement occurs.
The effect on intrusive tooth mobility of noradrenaline injected locally in monkeys
Authors: Slatter Janet M. , Picton D. C. A.
Published: July 2006

The experiments were carried out on four adult monkeys (Macaca irus) under pentobarbitone sodium anaesthesia in order to find the effect produced by a local injection of 1:10,000 noradrenaline on intrusive movements of the incisor teeth. This intrusive mobility was measured with a transducer, incorporating silicon strain gauges, while a strain gauge dynamometer was used to apply manual force approximately parallel to the long axis of the tooth. The mobility was assessed periodically by giving five thrusts preceded by intervals of 10 seconds. After two initial series of thrusts a submucous injection of 1:10,000 noradrenaline was given labially and lingually. The mobility was then assessed periodically for several hours. Seven control teeth were studied by injecting 1 ml. of physiological saline.

It was found that with injections of noradrenaline the mobility decreased over a period of 1 to 1½ hours and then returned towards its original mobility, whereas no comparable alteration in the intrusive mobility was detected when physiological saline was injected. It is concluded from force‐movement curves that the reduction in the vascular supply to the periodontium which may be presumed to occur substantially reduced the initial movement due to loads below 100 gf (0.981 N) and caused a progressively greater reduction as the load increased to 250 gf (2.451 N).
Comparison of various plaque parameters in individuals with poor oral hygiene
Authors: Loesche Walter , Green Edward
Published: July 2006

The control of plaque formation on tooth surfaces would appear to be a major goal of preventive dentistry. Several subjective scoring procedures for estimating plaque have been described. In the prresent investigation, stained and unstained plaque scorres were compared with various physical characteristics of plaque such as dry weitht, wet weight, microscopic count, absorbance of dispersed plaque suspensions, nitrogen and carbohydrate content. An institutionalized population that exhibited moderate to severe gingivitis and heavy plaque accumulations was studied. Significant correlations between the gravimetric measurements and microscopic count with either gingivitis scores or the unstained plaque scores were found. The stained plaque scorre showed no correlation with plaque weight or gingivitis scores in this population.
Effects of topical application of chlorhexidine on plaque and gingivitis in monkeys
Authors: Johnson N.W. , Kenney E.B.
Published: July 2006

All teeth except the lower right canine, premolars and molars, in each of 4 adult male macaque monkeys with heavy plaque deposits and severe gingivitis, were scaled and polished daily for 5 days, followed by daily topical applications of 2% aqueous chlorhexidine gluconate. Minimal amounts of simple plaque containing epithelial cells and Gram positive cocci formed on the treated teeth whereas the untreated teeth retained heavy deposits of complex plaque. In chlorhexidine treated areras the clinical level of gingivitis appeared to subside to a minimum after 15‐20 days. Histomorphometric assessments of gingivitis after 42 or 52 days treatment were made on decalcified paraffin sections, by measuring the total area of gingival connective tissue and the area containing inflammatory cells and calculating the proportion of gingival tissue affected. A total of 21 teeth were assessed. Untreated teeth had from 16‐40% of the gingivba inflamed, treated teeth only 0‐6%. Thus daily topical application of chlorhexidine significantly inhibits plaque accumulation and maintains a significant reduction in gingivitis in these animals. No differences in the nature or degree of keratinization could be detected between treated and untreated areas, nor were there any visible side effects of the use of chlorhexidine for this period.
Host tissue response in chronic periodontal disease
Authors: Schectman L. R. , Ammons W. F. , Simpson D. M. , Page R. C.
Published: July 2006

The histologic features of the non‐inflamed periodontium and the histopathologic manifestations of inflammatory gingival and peridontal disease were studied in fifteen wild‐caught adult marmosets. The non‐inflamed peridontium differs form that of humans in that keratinizing epithelium is more widely idstributed, red bone marrow is found in the alveolar bone around most of the teeth, and ther is a lamina propria‐like zone immediately subjacent to the epithelial basement membrane. This zone is comprised predominantly of mononuclear phgocytic cells. The histopathologic manifestations of periodontal disease in this animal include vascular proliferation, infiltration of polymorphonuclear neutrophilic leukocytes, proliferation and pentration by the epithelial rete ridges, and a marked increase in the population of mononuclear phagocytic cells. Notably, the plasma cell‐lymphocyte infiltrate characteristically seen in man is not a prominent feature of the disease process in the mamoset.
Rate of 3H‐proline incorporation into the rat periodontal membrane during pregnancy
Authors: Kameyama Y.
Published: July 2006

The rate of incorporation of 3H‐proline into the periodontal membrane was ascertained by autoradiography. The periodontal membranes of the pregnant rats exhibited a lower rate of 3‐proline incorporation than those of the non‐pregnant animals. The difference between the two rates of incorporation was statistically significant (p<.01). However, a significant difference was not observed between the rates of 3‐proline incorporation into the periodontal membranes of the sixteen day and nineteen day pregnant animals.
Identification of tissue and bacterial hyaluronidase in human saliva
Authors: Hopps R.M. , Prout R. E. S.
Published: July 2006

Determination of hyaluronidase activity in the saliva of human subjects has shown that two types of hyaluronidase, distinguishable on the basis of their different pH optima, are present. One is considered to be of bacterial origina and the other of tissue origin.
Oxygen consumption in different degrees of gingivitis
Authors: Zajíček O. , Kindlová M.
Published: July 2006

Endogenous consumption of oxygen by human gingiva in various inflammatory degrees was determined polarographically. The gingival biopsies were divided into 4 groups according to the histological degree of inflammatory infiltration. The oxygen uptake was mensuted for 5 hours. The differences in the RA quotient values among the individual groups were found insignificant (RA ‐ oxygen amount in mg, consumed by 1 gram of dry matter of the tissue per hour). Statistically significant differences were found in the rate of decrease of the RA.
Studies on the biology of the periodontium of marmosets
Authors: Dreizen S. , Levy B. M. , Bernick S.
Published: July 2006

Four adult cotton top marmosets fed a purified high cholesterol‐high fat diet developed a malabsorption induced osteomalacia which involved the periodontal bone. The alveolar bone changes were denoted histologically by a narrowing and disruption of the cortical and cribriform plates and by the presence of broad bands of osteoid around the remaining compact and spongy bone elements. Radiographically, the changes were represented by a partial to complete loss of the lamina dura and by a greatly increased patch radiolucency of the mandible and maxilla.
A routine mouse gingivectomy procedure for periodontal research in aging
Authors: Tonna E. A.
Published: July 2006

A micro‐surgical procedure was developed for the performance of simple, routine, standardized gingivectomies on the mesial papillae of the maxillary first molars of mice of different age. The application of subcutaneously administered sodium pentobarbital as anaesthetic, allowed for the handling of large numbers of animals in assembly‐line fashion with an animal loss of approximately 1%. The gingivectomies were performed under a stereomicroscope with remote focusing control at a magnification of 10 X using surgical microcurettes. A fiber‐optics cold light source was used to illuminate the surgical field.
Histologic and autoradiographic evaluations of long term gingival wound sites in adult rats
Authors: Tiber A. , Stahl S. S. , Weiner J. M.
Published: July 2006

Eight Sprague‐Dawley male rats were injured at the gingival papillae mesial to the maxillary left first molars. Groups of these rats and controls were sacrificed 9 and 12 months after injury. Prior to sacrifice, all animals received 0.5μc of tritiated thymidine per gram body weight by intraperitoneal injection. Jaws were dissected out and prepared for histologic and autoradiographic analysis. Measurements at the wound and respective control sites indicated accelerated gingival recession at the sites of injury. Labeling indices, however, were similar at both areas examined. Within the limits of the experiment, the observations suggest similar functional demands at both sites regardless of the position of the marginal gingiva, but do not determine the reason for accelerated gingival recession at the wound sites with time.
Experimental periodontitis in the Beagle dog
Authors: Lindhe Jan , Hamp Sven‐Erik , Löe Harald
Published: July 2006

The purpose of the present investigation was to study the sequential stages in the development of a periodontal lesion starting from a healthy periodontium. Twenty inbred Beagle dogs 10 months of age and weighing 10–12 kilos were used. The animals were equally divided into one experimental and one control group. Throughout the experiment all dogs were given a diet containing 400 gm pellets and 25 gm soya flower. From day zero the teeth (in the left jaws) of the control dogs were twice dally subjected to a careful but gentle brushing with tooth brush and dentifrice. The teeth of the experimental group animals were not cleaned. The dogs were examined at regular intervals during an 18 month period.

The results show that it is possible in young dogs to induce gingivitis which gradually develops into periodontitis simply by allowing plaque to accumulate on teeth. The cleaned teeth did not show signs of gingivitis or periodontitis during the entire experiment. It is proposed that in the Beagle dog the progression of the lesion during an 18 month period may occur in three stages: I) subclinical gingivitis, II) clinical gingivitis and III) periodontal breakdown. Subclinical gingivitis was characterized by a rapidly increasing gingival exudation and migration of crevicular leukocytes, i. e. signs off acute inflammation. Clinical gingivitis was characterized by changes in gingival colour, texture and bleeding tendency but only minor alterations of the number of crevicular leukocytes. Periodontal breakdown, characterized by loss of subgingival fiber attachment, occurred only in areas of clinical gingivitis.
Pentose shunt enzyme activities in non‐inflamed attached gingiva of dogs
Authors: Bergquist J. I. , Nuki K.
Published: July 2006

Ultramicrochemical methods were used to assay glucose‐6‐phosphate dehydrogenase (G‐6‐PDH) and 6‐phosphogluconale dehydrogenase (6‐PGDH) activities in non‐inflamed attached gingiva of dogs, these enzymes being an integral part of the pentose shunt. Precautions were taken to assure the clinical non‐inflamed status of the gingivectomy specimens. Frozen dried sections were dissected under a stereomicroscope into representative morphologically distinct fragments which ranged in weight from 12 to 240 nanograms (10‐9 grams). Quantitative results for various strata of epithelium, connective tissue and whole epithelium were calculated. The mean combined G‐6‐PDH and 6‐PGDH activities in micromoles of substrate converted., per gram of dry tissue per minute at 37° C. were: surface layer, 17.7; granular layer, 56.4; spinous layer, 58.1; basal layer, 49.5; connective tissue, 15.8; and whole epithelium, 46.6. The mean 6‐PGDH activities in micromoles of substrate converted per gram of dry tissue per minute at 37° C. were: surface layer, 6.8; granular layer, 22.1; spinous layer, 17.5; basal layer, 20.8; connective tissue, 4.2; and whole epithelium, 16.9. The mean values for G‐6‐PDH activity were: surface layer, 10.9; granular layer, 34.4; spinous 40.6; basal 28.7; connective tissue, 11.6; and whole epithelium, 29.7. The results are compatible with the pattern of enzyme activity previously reported for primate skin (lm and Adachi, 1966) and rat palate (Gerson. 1967).
Morphological changes in gingival blood vessels during developing gingivitis in dogs
Authors: Söderholm G. , Egeleerg J.
Published: July 2006

Blood vessels situated at the gingival margin were studied in dogs during a 16‐day period of developing gingivitis. Morphological changes in the vessels were assessed from photographs which had been taken periodically and were identical. Two characteristic alterations were found: increased width and changes in the course of the vessels. Increases in width were observed during the first week of the experiment. Changes in the course of vessels were found during the second week.
Stresses in the periodontal ligament
Authors: Hillam D. G.
Published: July 2006

Measurements have been made of the root areas of forty five extracted teeth. These have been used to calculate the theoretical pressures that may occur in the region of the alveolar crest and their increase with progressive loss of alveolar bone when a lateral force is applied to the crown of the tooth. Pressures generated in the periodontal ligament as a result of axial loadings have also been calculated and compared with those due to lateral loadings. The results suggest that a very rapid increase in pressures in the periodontal ligament would occur with bone losses in excess of 55 per cent in the case of lateral loadings and over 80 per cent in the case of axial loading. The implications for clinical practice are discussed.
Optimal dosage and method of delivering chlorhexidine solutions for the inhibition of dental plaque
Authors: Gumming Boyd R. , Löe Harald
Published: July 2006

The study evaluated the effect of increasing the amount of rinse solution upon the concentration of chlorhexidine needed to control plaque formation, compared the application of chlorhexidine with an oral irrigator to normal rinsing, and examined the amount of staining caused by the various dosages. Forty‐four dental students were divided into 7 groups which each used different volumes (700, 400, 200, applied with an oral irrigator and 200, 100, 50 and 20 ml used with normal rinsing). On a rotational basis, the individuals tested all concentrations (0, .01, .025, .05, .075, .1, .15 and .2 per cent) once during each 9 day test period of suspended oral hygiene. The plaqoe accumulation was. assessed at the end of each trial period according to the criteria of the Plaque Index system. Each lest period was separated by 5 days of normal oral hygiene. The study has shown that if larger volumes are used much lower concentrations of chlorhexidine are necessary, plaque inhibition in the posterior portion of the oral cavity is better with an irrigator than with normal rinsing and that staining is less with large volumes of dilute concentrations than with small volumes of stronger concentrations.
Comparative metabolism of 4‐14C‐progesterone in normal and chronically inflamed human gingival tissue
Authors: Elattar T. M. A. , Roth G. D. , Hugoson A.
Published: July 2006

The In Vitro metabolism of 4‐14C‐progesterone in six normal and eight chronically inflamed gingival tissues has been investigated. The inflamed gingiva has been twice as active as the normal in converting progesterone to 5α and 5β‐pregnandiones, 20α‐dihydroprogesterone, and other unidentified polar compounds. The clinical implications of these findings as related to gingivitis have been discussed.
Optimal dosage and method of delivering chlorhexidine solutions for the inhibition of dental plaque
Authors: Cumming Boyd R. , Löe Haral
Published: July 2006

The study evaluated the effect of increasing the amount of rinse solution upon the concentration of chlorhexidine needed to control plaque formation, compared the application of chlorhexidine with an oral irrigator to normal rinsing, and examined the amount of staining caused by the various dosages. Forty‐four dental students were divided into 7 groups which each used different volumes (700, 400, 200, applied with an oral irrigator and 200, 100, 50 and 20 ml used with normal rinsing). On a rotational basis, the individuals tested all concentrations (0, .01, .025, .05, .075, .1, .15 and .2 per cent) once during each 9 day test period of suspended oral hygiene. The plaque accumulation was assessed at the end of each trial period according to the criteria of the Plaque Index system. Each test period was separated by 5 days of normal oral hygiene. The study has shown that if larger volumes are used much lower concentrations of chlorhexidine are necessary, plaque inhibition in the posterior portion of the oral cavity is better with an irrigator than with normal rinsing and that staining is less with large volumes of dilute concentrations than with small volumes of stronger concentrations.
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.
The effect of ascorbic acid on the turnover of collagen in bone in tissue culture
Authors: Golub L. M.
Published: July 2006

Ascorbic acid is required for collagen synthesis but its role in other aspects of collagen metabolism is unclear. Neonatal mouse calvaria were incubated in tissue culture in the presence of 0·05 or 50·0 μg/ml ascorbic acid to determine the effect on bone collagen synthesis, crosslinking and degradation. H3‐proline was added to the culture media to label the collagen newly synthesized in vitro with H3‐hydroxyproline. Ascorbic acid increased the synthesis but descreased the degradation of the H3‐hydroxyproline‐labeled bone collagen. Ascorbate increased the specific activity (CPM H3‐hyp/μg hyp) of the insoluble collagen, with no effect on the acid‐soluble collagen, indicating that the newly synthesized bone matrix was more highly crosslinked. On the other hand, the degradation of the preformed unlabeled collagen appeared to be increased. It was concluded that ascorbic acid increased bone collagen remodeling in vitro by favouring the the accumulation of newly synthesized bone collagen and the removal or degradation of the older preformed material.
Comparative metabolism of 4‐14C‐progesterone in normal and chronically inflamed human gingival tissue
Authors: El Attar T. M. A. , Roth G. D. , Hugoson A.
Published: July 2006

The In Vitro metabolism of 4‐HC‐progesterone in six normal and eight chronically inflamed gingival tissues has been investigated. The inflamed gingiva has been twice as active as the normal in converting progesterone to 5α‐ and 5β‐pregnandiones, 20α‐dihydroprogesterone, and other unidentified polar compounds. The clinical implications of these findings as related to gingivitis have been discussed.
Consistency of plaque distribution in individuals without special home care instruction
Authors: Cumming Boyd R. , Löe Harald
Published: July 2006

The consistency of the individual patterns of plaque distribution was evaluated over a period of time. Fifteen, first semester dental students, who had not received special home care instructions, were evaluated on five alternate days according to the criteria of the Plaque Index system. The study has shown that the pattern of plaque distribution demonstrated by each of the individuals was unique. Also, while various regions of the dentition were sometimes free from plaque and sometimes covered by plaque other areas existed in the mouths of all subjects which were consistent: either clean or covered by plaque. The clinical implications of these findings are discussed.
Localization of mucopolysaccharides in epithelial‐like cells cultured in vitro
Authors: Thonard J. C. , Wiebkin O. W.
Published: July 2006

Previous studies demonstrating mucopolysaccharides (MPS) in tissue cultured epithelial cells did not eliminate the possibility that some of the reported staining could be attributed to acidic lipids, nucleic acids and substrate movement, although these possibilities were deemed minimal due to the employment of generally accepted techniques. Human amnion cells were grown on coverslips in tissue culture. Some coverslips were treated to remove MPS, lipid or nucleic acids before fixation and staining, whilst others were merely fixed and stained. Fixatives included 10 % formalin, 10 % formalin in 80 % ethanol, 1 % cetylpyridinium chloride and 1 % cetylpyridinium chloride in 80 % ethanol. Stains employed were the Hale colloidal iron, alcian blue, toluidine blue at pH 6·0 and 2·5 and sudan black. Substrate extractions were effected with testicular hyaluronidase, ribonuclease, KOH and pyridine. The present report confirms earlier results and provides evidence that human epithelial‐like cells produce MPS in vitro the staining specificity of which eliminates lipids and nucleic acids as the source of the observed reactions. It is claimed that the MPS is mainly confined to the cell surface and therefore is more discernible as a MPS stainable moiety in contiguous cell cultures than when cells are dispersed singly.
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.
Intracellular collagen fibrils in the periodontal ligament of the mouse, rat, hamster, guinea pig and rabbit
Authors: Listgarten M. A.
Published: July 2006

The periodontal ligaments of the mouse, rat, hamster, guinea pig and rabbit were examined by electron microscopy. The study revealed the constant and frequent occurrence of intracytoplasmic collagen fibrils with the typical banding of native collagen. These fibrils appeared singly or in bundles within cells with cytological features of fibroblasts. Some fibrils were aggregated laterally into fibers measuring up to 0.2 μm. Most fibrils were surrounded by a limiting membrane. The fibrils are believed to represent ingested collagen in a connective tissue with a high turnover rate.
Structural changes in exposed human cementum
Authors: Armitage Gary C. , Christie Thomas M.
Published: July 2006

Frozen sections of 75 decalcified human teeth with root surfaces exposed to the oral environment during periodontal disease were examined for the presence in cementum of “pathologic granules” (Bass 1951, Benson 1963). In 72 of these teeth granule‐like formations were found in exposed cementum. In only one instance were the granules also found under an unexposed root surface. A possible explanation for this exception was presented. The cemental granules do not appear to be artifacts of fixation, decalcification, or freezing. Mineralized ground sections of exposed roots did not exhibit any structural changes resembling the granules. However, upon decalcification the granules appeared. This suggests that areas from which the granules arise are filled with calcified material.
Structural changes in exposed human cementum
Authors: Armitage Gary C. , Christie Thomas M.
Published: July 2006

The purpose of this study was to determine if the granules observed in frozen sections of exposed human cementum with the light microscope can be detected with the electron microscope. Electron‐microscopic examination of decalcified exposed roots revealed the presence of vacuole‐like formations deep in the cementum. The vacuoles frequently followed morphologic patterns of collagen fibrils in the cementum and underlying dentin. Both the granules and vacuoles (1) have a similar distribution, (2) are in the same size range, (3) have the same basic shape, and (4) are found in the same specimens.
Comparison between orifice and intracrevicular methods of sampling gingival fluid
Authors: Egelberg Jan , Attström Rolf
Published: July 2006

Regular tooth cleansing was abolished during four days in a group of humans and a group of dogs with healthy gingiva. In another group of dogs with chronic gingivitis their soft diet was exchanged with a hard diet for one day. The effects of these procedures on the amounts of gingival fluid were studied using both the orifice and the intracrevicular method of sampling. The results of the comparison indicate that the two methods are comparable to reveal changes in gingival inflammation.
A reproducible method for evaluating radiographic changes in periodontal defects
Authors: Brown I. Stephen , Owings James R.
Published: July 2006

A standardized radiographic method has been presented for evaluating longitudinal changes in periodontal defects. The technique employs metallic endosseous implants, radiopaque pocket probes and markings on the tooth to provide constant points of reference from which accurate interpretation of diagnostic radiographs may be made. The data suggest that inherent in this method is a very small degree of variability, and that it may be a more useful technique to incorporate in future clinical investigations than conventional use of the periodontal probe.
Effect of tobacco‐ smoking on periodontal tissue of 15‐year‐old schoolchildren
Authors: Preber H. , Kant T.
Published: July 2006

193 schoolchildren 15 years of age were grouped as non‐smokers and smokers on the basis of their smoking habits. In all cases an X‐ray examination was made of the lower incisors, and a record was made of plaque and gingival index. The resulting values were compared between non‐smokers and smokers. The following conclusions could be drawn. Oral hygiene and gingival inflammation are directly correlated. Oral hygiene is worse in smokers than in non‐smokers. The gingival status is worse in smokers than in non‐smokers. When investigating gingival status on the same level of oral hygiene, no significant difference is found between the groups.
A new approach to the evaluation of Plaque Index scores
Authors: Birkeland J. M. , Jorkjend L.
Published: July 2006

The aim of the present study was to evaluate and compare methods of expressing the plaque situation recorded by the Plaque Index System (Silness and Löe 1964). Basic information based on 48 plaque recordings in each of 154 children indicated 16 ± 13% score 0, 63± 13% score 1, and 19± 14% score 2. The criteria of the Plaque Index System are at the ordinal or ranking level of measurement, whereas means and standard deviation should be performed at the interval and ratio scales of measurements, i.e. on the frequencies of the scores. Re‐examinations of the children as well as a toothbrushing experiment indicated that the frequency of score 2 adequately expressed the plaque situation. The conventional toothbrushing seemed to have no effect on the total number of score 1.
Necrotizing ulcerative gingivitis in mongoloid and non‐mongoloid retarded individuals
Authors: Harvey Brown R.
Published: July 2006

A survey of the records of dental treatment of 846 children and adults resident in a hospital for the mentally retarded was made to determine the proportions of mongoloid and non‐mongoloid subjects who had experienced necrotizing ulcerative gingivitis. The records covered a period of 10 years for long‐term residents and from the time of admission for those who were resident for less than 10 years. Eight hundred and six subjects had natural teeth present during some or all of the period of study. Thirty‐five percent of mongoloids had experienced one or more episodes of necrotizing ulcerative gingivitis, compared with 4% of non‐mongoloids (x2= 130·95, P<.001). Of those subjects who had experienced the condition. 49·1 % of mongoloids and 26·9 % of non‐mongoloids had recurrences. Episodes of necrotizing ulcerative gingivitis were associated with rapid progression of periodontal disease in mongoloids. The mean ages at the time of the first episode were 9·4 years for mongoloids and 9·9 years for non‐mongoloids.
Studies of mast cells in the human gingival
Authors: Angeiopoulos A. P.
Published: July 2006

Supported in part by the National Institutes of Health Grant H‐5338 and the Medical Research Council of Canada Grant MA‐3604. The author thanks Mr. Taki Costopoulos for the drawings and Mr. G. K. Castle for the preparation of photographic prints included in this paper.
The acidic glycosaminoglycans of gingiva of diabetic rats
Authors: Kofoed J. A. , Tocci A. A.
Published: July 2006

Rats made diabetic by administration of alloxan monohydrate showed in gingiva a 35.9 % reduction in total glycosaminoglycans concentration. The concentration of hyaluronic acid was 48·4 % and that of chondroitin‐4‐sulfate 45·2 % decreased. Heparin concentration was 23·8 % increased. The other sulfate fractions did not appear to be affected. The administration of insulin almost entirely restored the level of the affected glycosaminoglycans to normal values with the only exception of heparin.
Gap junctions in human gingival keratinized epithelium
Authors: Barnett M. L. , Szabo G.
Published: July 2006

Gap junctions were found in all layers of human gingival keratinizing epithelium, except the stratum corneum. En bloc staining revealed the seven‐layered structure of these junctions, with a gap of approximately 20Å between the outer leaflets of adjacent unit membranes. Treatment of specimens with lanthanum strikingly demonstrated the gap junctions, since the lanthanum completely fills the central gap. Oblique and tangential sections of gap junctions in lanthanum‐treated specimens produced characteristic striated and honey‐comb appearances, respectively. It appears as though many junctions in gingival epithelium formerly thought to be variants of tight junctions (and thus regions of membrane fusion) are, in reality, gap junctions. In view of findings regarding the function of gap junctions in other tissues, it is suggested that gap junctions have a significant role in the synchronous differentiation of normal human gingival keratinizing epithelium.
Ultrastructural changes of basal lamina and anchoring fibrils of gingiva in vitro
Authors: Sugimoto A. , Rose G. G. , Takarada H. , Cattoni M.
Published: July 2006

Biopsies of human gingiva were studied with special reference to the ultrastructural changes of the basal lamina and anchoring fibrils occurring after periods of in vitro cultivation. Characteristic changes were found in the basal lamina and anchoring fibrils. In the early stages in vitro, the basal lamina showed detachment from the epithelial cells, interruption, irregularity in thickness, and reduplication; the anchoring fibrils increased in number. In the later stages in vitro, the basal lamina showed a more severe detachment and fragmentation, proliferation into the connective tissue, and face–to–face coalescence, while the anchoring fibrils became stable in number and free of association with the connective tissue components.
Activity of glucose‐6‐phosphate dehydrogenase and acid phosphatase in nonkeratinized and keratinized oral epithelium and epidermis in the rabbit
Authors: Gerson Stanley
Published: July 2006

There are very few reports in the literature on biochemical and histochemical comparative studies of enzyme activity in nonkeratinized and keratinized regions of oral epithelium in the same individuals of a species. Reported studies have dealt for the most part only with keratinized epithelium, and they suggest an important role for glucose‐6‐phosphate dehydrogenase and acid phosphatase in the process of keratinization. This is based on increasing activity of the two enzymes towards the surface of keratinized epithelium and decreasing activity in nonkeratinized. To eliminate the possibilitv that the differences observed are individual or species differences, non‐ keratinized and keratinized oral epithelia from the same animals were assayed. The ratio of activity in keratinized epithelium to that in nonkeratinized reachcd 13:l for acid phosphatase and 2:1 for glucose‐6‐PO4 dehydrogenase. In nonkeratinized, activity of both enzymes decreased steadily towards the surface. In keratinized, acid phosphatase increased dramatically towards the surface; glucose‐6‐PO4 dehydrogenase increased at first and then decreased. These findings offer evidence that the biochemical activities represented by the two enzymes have an important role in keratinization.