摘要:

Dental plaque is the aetiologie factor common to caries and chronic periodontitis. Understanding of the structure of this microbial film has been hindered by the fact that conventional methods of fixation and embedding are more or less disruptive in their effects. Freeze‐etching provides a means of examining plaque at an ultrastructural level in a state more closely approximating to that existingin vivothan is possible with other methods. The technique has been applied to the study of several oral commensal bacteria.Nocardia, Bacillus subtilisandStreptococcus viridansspecies have been shown to possess particulate cytoplasmic membranes, more particles being present on outer than on inner aspects. The previously described pattern of the spore coat ofB. subtilisis confirmed, and, as in other non‐oral species, the organisms examined appeared to possess regularly structured cell walls. The banded appearance ofS. viridansis similar to that inS. mutansrecently seen using scanning electron microscopy.Similar features of cell wall and cytoplasmic membrane have been observed in samples of dental plaque. Specimens resembling outer (salivary) surface plaque as prepared for conventional electron microscopy were found to contain numerous types of organism, principally coccal, in a fairly homogeneous matrix. Many cells possessed intracytoplasmic organelles. In the deeper layers, extracellular bodies were sometimes visible in the interbacterial matrix. Several types of fibrillar component were observed, passing between adjacent bacterial membrane layers, extending from the cell wall into the plaque matrix and connecting adjoining organisms. It is suggested that such fibrillar structures may be as significant in maintaining attachment of micro‐organisms to one another and to the tooth surface as any inherent stickiness of polysaccharides. Some organisms were found to be joined to one another by broad, structureless junctional zones. Many organisms possessed intracytoplasmic inclusions and cells were frequently se

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00634.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

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 occ

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00635.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Two methods were used to induce gingival inflammation in squirrel monkeys (8 ovariectomized females and 3 males) with known levels of progesterone, estrogen and cortisol. Plasma progesterone and cortisol were assayed by a competitive binding technique. A bioassay of vaginal epithelium was used to assess estrogen activity. The ovariectomized animals were divided into two equal groups. Group I was injected with 10 mg progesterone and 0.2 mg estrogen twice daily for 50 days, producing elevated levels of these hormones. The remaining females (Group II) and the males (Group III) received vehicle for the same length of time. Regardless of the manner by which it was induced, gingival inflammation, as assessed by histometrics, was most severe in ovariectomized animals with no detectable progesterone and minimal estrogen (Group II). Group II, also, had lower levels of cortisol than the ovariectomized animals receiving progesterone and estrogen (Group I) and the males (Group III).

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00636.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Horizontal tooth mobility was determined in 31 females during the course of one complete menstrual cycle. No significant changes in horizontal tooth mobility were observed concomitant with the menstrual cycle. Fourteen females reported the regular use of anovulatory drugs. No significant changes in horizontal tooth mobility were observed. Tooth mobility was significantly less among the anovulatory drug users.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00637.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The normal periodontium and manifestations of gingival and periodontal disease were studied in 120 living marmosets (Saguinus oedipus) and in the skulls of 40 additional animals to determine the possible usefulness of the marmoset as a model for investigation of the host tissue response in chronic periodontal disease. The general clinical and anatomic features of the animal are very similar to those seen in man; however, most of the adult animals exhibit severe occlusal abrasion and evidence of occlusal traumatism. Although gingival inflammation was observed in almost all of the animals examined, only 18.2% of the total gingival units were affected and the severity was exceptionallly limited. The prevalence of bony lesions indicative of the presence of chronic inflammatory periodontal disease was 0.5% and all of the lesions observed were associated with open contacts or plunger cusps. Thus, the prevalence of spontaneous chronic progressive periodontal disease in wild‐trapped marmosetes appears to be very lo

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00638.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

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

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00639.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The lateral incisors of 2 cynomolgus monkeys were removed with the adjacent gingivain situat intervals of 12 to 49 days after gingivectomy. Electron microscopic examination of the specimens indicated that epithelial reattachment may occur in 12 days or less under these experimental conditions. Hemidesmosomes and a basement lamina were regenerated against enamel as well as coronal and root cementum surfaces. Reattachment appeared to occur against both morphologically normal and superficially altered cementum. Enamel lamellae extending through the thin coronal cementum layer were not disturbed during the surgical procedure. Hemidesmosomes appeared to regenerate more rapidly than the basement laminas against either the tooth surface or the gingival connective tissue.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00640.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The subepithelial connective tissues of chronically inflamed gingiva were infiltrated by numerous well developed plasma cells. These cells were usually grouped together forming islands of cells which exhibited similar degrees of cytoplasmic differentiation. Young plasma cells contained well developed Golgi areas and an abundant system of granular endoplasmic reticulum, in the form of parallel stacks of flattened cisternae. In more mature plasma cells the cisternae of the granular endoplasmic reticulum were usually dilated by an accumulation of granular material Occasional plasma cells contained extremely large elements of endoplasmic reticulum (Russell bodies) while others contained crystalloid deposits within the cistemae of the reticulum. The degeneration of plasma cells with a consequent release of their cytoplasmic contents was frequently observed. Such cells were usually located near the sulcular epithelium while most of the normal plasma cells were usually located within the deeper connective tissue. These observations suggest that the liberation of antibody in the region of the inflamed sulcular epithelium may proceed via the degeneration of mature plasma cells.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00641.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

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.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00642.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

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 p

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1972.tb00643.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY