摘要:

The amphoteric acid dyes acid fuchsin, aniline blue WS, azocarmine G, fast green FCF, light green SF and the wholly acid dye thiazine red R were used for fluorochromy of mast cells in sections of formalin or alcohol-formalin fixed rat tongues. By ordinary light the mast cell granules were barely visible. By UV or blue light exitation, however, a selective, secondary fluorescence of varying intensity and contrast against the tissue background manifested itself. By thin layer chromatography each dye revealed 3-7 components. Except for aniline blue WS, the main component(s) of each dye conferred to the granules the same fluorescence as the corresponding whole dye. These results of fluorochromy, together with the findings of methylation and deamination experiments, allowed the assumption that the anionic groups of the dyes were bound to unoccupied basic groups of the mast cell. granules.

ISSN:0001-6357    

DOI:10.3109/00016357809027567

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

In the present paper an implantation technique is described whereby the effect of the surgical operation is eliminated and initial tissue reactions to materials may be studied. A teflon body was implanted intramuscularly in rabbits. After six weeks the overlaying tissue was excised and the implant removed. An intact, nonepithelialized tissue surface was exposed, which due to the shape of the implant showed three indentations. Materials were placed in the indentations for 15 minutes and the tissue reaction was registered by enzyme histochemical methods. Silicate cement, zinc phosphate cement and a 4% phenol solution caused an inhibition in the dehydrogenase enzyme activity in the tissue subjacent to the indentations. The seventy of the tissue reaction, indicated by the width of the inhibition zone, varied among the test materials. Silicate cement caused the widest inhibition zone and the phenol solution the narrowest one. These results correlate well with previous tissue compatibility studies and indicate that the method is applicable for in vivo screening of initial tissue response to biomaterials.

ISSN:0001-6357    

DOI:10.3109/00016357809027568

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

The quantity of the remaining unreacted methacrylate groups in polymerized composite materials has been determined. Six proprietary composites were investigated by infrared multiple internal reflection spectroscopy. Infrared reflectance measurements were made before polymerization and refeated after the composites were subjected to polymerization at 37 C for 24 hours. The quantities of remaining unreacted methacrylate groups were determined and the data expressed as percentages of the total amount of methacrylate groups in the unpolymerized materials. The specimens were specially prepared to ensure that the surface properties simulated the bulk properties of the polymerized composites. The quantities of remaining methacrylate groups in the six composites determined by this surface measuring technique ranged from 25 to 48 %. The results demonstrate that commercially available composite materials exhibit different degrees of conversion 24 hours after the start of polymerization. These differences can be correlated to the different monomer compositions of the composite restorative resins.

ISSN:0001-6357    

DOI:10.3109/00016357809027569

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

It was the purpose of the study to test the efficacy of brushing with a 1% chlorhexidine gel or a commercial solution cleanser (Steradent®) in preventing formation of plaque on the fitting surface of new dentures. The study group consisted of 74 denture wearers with denture stomatitis who were assigned randomly to one of four treatment groups, testing either the chlorhexidine gel, a placebo gel, Steradent®, or a placebo solution. The experiment was started immediately after denture treatment was completed. The experimental period was 1 month. The amount of denture plaque, the clinical condition of the palatal mucosa, and the concentration of yeasts in mucosal and denture smears were recorded while the patients used their original dentures and after the experimental period. Plaque had formed on all new dentures but to a smaller extent in the groups testing the chlorhexidine gel or the placebo gel. The study does not provide any obvious evidence of a chemical effect of chlorhexidine gel or Steradent®as a means to prevent formation of microbial plaque on the mucosal surface of maxillary complete dentures.

ISSN:0001-6357    

DOI:10.3109/00016357809027570

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Oral hygiene, periodontal health and periodontal treatment needs were studied in the dentulous patients (n = 328) of a sample selected to be representative of all institutionalized mentally subnormal persons in Norway aged 5-45. The average oral hygiene and periodontal health was poor except for patients in a few institutions where the nurses were trained to clean teeth regularly. Increased age, epilepsy, Down's syndrome and a high degree of mental deficiency were all elements that apparently contributed to impairment of periodontal health and to increased treatment requirements. The preventive programs used in some institutions seemed to be effective. Still better results, however, could probably be obtained by the use of dental hygienists.

ISSN:0001-6357    

DOI:10.3109/00016357809027571

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Attramadal, A.&Jonsen, J. Heavy trace elements in ancient Norwegian teeth.The present work was undertaken in order to determine the content of lead, cadmium, copper and zinc in 26 teeth retrieved from burial-grounds in various parts of Norway, dated from A.D. 200 up to 1850. The analyses were made by differential pulse stripping voltammetry on hydrochloric acid digests of the teeth. High levels of lead were found in teeth dated from ca A.D. 1500 from Gimsøy Kloster and Tønsberg. Teeth originating from A.D. 200 showed a high content of Cd, Cu and Zn.

ISSN:0001-6357    

DOI:10.3109/00016357809027572

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

The stress/strain behavior at different strain rates and the creep rate of dental amalgams were evaluated and compared to the microstructure. The results indicate that substantial differences exist both in strength and strain at fracture. The strain at fracture for high strain rates was associated with the nature of the particle-matrix interface, in that amalgams with an interpenetrating interface exhibited some ductility, while amalgams with an abrupt interface exhibited practically no plastic deformation at fracture.The correlation between creep and slow compressive strength was verified and it was suggested that grain boundary sliding was the deformation mechanism in both cases.

ISSN:0001-6357    

DOI:10.3109/00016357809027573

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor