摘要:

Thermal injury to the periodontium via the root canal was produced in 12 squirrel monkeys in order to study the sequence of events leading to ankylosis. Three days and one week following such injury an area of necrosis was found in the periodontal ligament which was circumferential, involved both periodontal ligament and alveolar hone, extended approximatelyl/3the length of the root and did not involve the epithelial attachment. Two and 3 weeks following thermal injury new fibroblasts and blood vessels were seen at the periphery of neerotic areas and progressively decreased the area of necrosis. This was accompanied by frontal resorption of bone and cementum. Rear resorption took place adjacent to areas where the periodontal ligament was still neerotic. By one month, healing had progressed so that neerotic tissue was no longer present, bone apposition was more prominant than resorption and in some areas tooth and bone had fused. Ankylosis persisted but a continuous remodeling process was taking place as evidenced by further resorption and bone formation until the end of the study (6 months).

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00604.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

The ultrastructural changes occurring during physiological resorption of connective tissue associated with erupting teeth of monkeys is described. Significant differences occur before and after the tooth emerges into the oral cavity. Before the tooth erupts connective tissue resorption over the tooth shows a cellular response involving cells of the fibrocytic and monocytic series. The cells of the fibrocytic series show changes from the resting fibrocyte which involve dilation of the cisternae of the rough endoplasmic reticulum, hypertrophy of the Golgi appearatus, the apparance of agranular vesicles, loss of the spiral configuration of polysomes and the development of numerous coated vesicles close to the cell surface. Ultimate breakup of the fibrocyte occurs. Monocytic cells become macrophagic. No breakup of macrophages occurs. In the extracellular compartment the collagen fibrils show a breakup into smaller units and eventual loss. The dental epithelium associated with this disorganized connective tissue is characterized by the development of numerous coated vesicles and a highly vesicular cytoplasm. The connective tissue and dental epithelium lateral to the crown of the tooth showed a similar ultrastructural picture which alters significantly as the tooth emerges into the oral cavity and the epithelial attachment develops. An acute inflammatory response occurs and the connective tissue supporting the forming attachment shows areas of breakdown and synthesis occurring simultaneously. These findings are discussed in terms of the mechanism of connective tissue breakdown and the fibrocyte implicated as playing an important role in this mechanism. It is suggested therefore, that the fibrocyte is capable of modulation to become either synthetic, maintaining or degradative.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00605.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

The effect of feeding normal rat cake, high sugar fat supplemented and high sugar fat‐free diets on the periodontal tissues of rats has been studied. It was found that feeding a fat‐free diet resulted in periodontal changes. The effect is considered to he due to the systemic effect or essential fatty acid deficiency with an associated contribution from impaction in the gingival crevice due to the physical consistency of the fat‐free

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00606.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

Human Gingival Tissues was clinically classified as normal or periodontally involved. Acid mucopolysaccharides were extracted from this tissue. The measurable acid mucopolysaccharides extracted were chondroitin sulfules A and C. Concentration of chondroitin sulfate was lower in the tissue classified as periodontally involved when compared to the normal tissue.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00607.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00608.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

The effect of experimental leukopenia induced by nitrogen mustard on chronic gingival inflammation has been studied in dogs. The effect on the gingivae was assessed by measurements of crevicular leukocytes, gingival fluid and the level of acid phosphatasc activity in samples from gingival crevices. During leukopenia a reduction in all these parameters was observed. The values returned to normal in the post‐leukopenic period. The results obtained indicate that crevicular leukocytes may contribute to the enzyme milieu in the gingival crevice and that these cells, through their lysosomal enzymes, may influence the tendency of the dento‐gingival vessels to show increased permeabil

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00609.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

Leukopenia was induced in six beagle dogs with chronic gingivitis by the injection of heterologous anti‐neutrophil scrum. During leukopenia, the number of neutrophils in the gingival crevice and within the gingival tissues was reduced. Concomitant with the reduction of neutrophils, the amount of gingival fluid decreased. The activity of acid phosphatase, hyaluronidase and protease in crevicular samples was determined and was found to decrease in parallel with the reduction in neutrophil number. All parameters returned to normal during the post‐leukopenic period. The results of the present study support previous suggestions that neutrophils at the dento‐gingival junction contribute to the enzyme milieu in the gingival crevice and that these cells, through their lysosomal enzymes, may induce vascular damage in periodon

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00610.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

There have been few previous investigations of the possible local effects on the gingivae of topically applied fluoride solutions and the results obtained have been contradictory. In the present study the immediate reaction of dog gingivae to topical application of sodium fluoride in concentrations of 0.2, 1.0 and 2.0 per cent, and the reaction to long term treatment by daily application of 2.0 per cent sodium fluoride solution to clinically healthy and chronically inflamed gingivae were studied. Immediate tissue reactions were assessed from changes of microvascular structure and function (Part 1). The effect of long‐term treatment was estimated from the amount of fluid in the gingival pocket (Part II). Application of sodium fluoride solutions to the crevicular epithelium in variably caused severe dysfunction of the blood vessels in chronically inflamed tissues but never of those in clinically healthy gingiva. Repeated topical applications of 2 percent NaF did not produce chronic gingivitis or aggravate an existing gingiviti

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00611.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

Using strain gauges, the method to be described measures the lateral force required to produce a standard deflection of toothbrush tufts. A deflector bar which remains stationary is attached to a cantilever which is stressed by the pressure of the brush moving across the deflector bar. The resulting strain is measured by using strain gauges which are connected via a Wheatstone bridge to an oscilloscope. Movements of the oscilloscope beam represent changes in the force exerted by the brush and are photographed on moving film.The effects on stiffness of changes in the rate of strain, length, diameter, wetness and temperature of nylon were investigated separately, and a standard test was devised which could assist in more accurate labelling of toothbrushes.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1971.tb00612.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY