摘要:

ABSTRACT –Toothbrushing for 21/2min and the use of toothpicks for 21/2 min produced bacteremia with streptococci in seven out of 13 patirnts with destructive periodontitis and in dontitis group and the “gingivitis” group was not significant, but there scemed to be more frequent bacteremia in the periodontal group. No correlation could be established between plaque‐index, gingival‐index and positive bacteremia. Barteremia seemed to be due primarily to pockets and interdental ulcerations. The use of chlorhexidine as a mouthriuse for 7 d did not reduce the bacteremia caused by the oral hygiene procedures in either of the two groups. After periodontal treatment no bacteremia was detected in the periodontitis group, whereas no reduction was obtained in the gingivi

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01895.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –The purpose of this study was to test the hypothesis that the pattern of calcification of dental plaque — either intracellularly or extracellularly — is dependent on the type of microorganisms present. Two strains ofBacterionema matruchotii. Strain 13 (Richardson) and Strain 14266 ATCC, were grown in an in vitro system and their calcification studied by transmission electron microscopy. Mineral crystals appeared in the specimens in scattered areas after 2 weeks of incubation, but consistently and in significant amounts after 4 weeks. In Strain 13 the crystals occurred only intracellularly, while in Strain 14266 the crystals were seen both within and around the bacteria. In the Strain 14266 specimens the extracellular crystals were often related to trilaminar vesicles and cell remnants. Differences in potential of calcification between closely related bacterial strains may partly explain the differences observed between calculus formers and non‐

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01896.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –The properties of different tetracyclines, alizarin red S, calcein, Procion H‐8B® and hematoporphyrin as fluorescent bone and dentin markers have been tested on growing Wistar rats after intraperitoneal injections. Tetracycline, alizarin red S, calcein and Procion H‐8B were individually identifiable by means of appropriate filter combinations of the microscope. This approach may be useful in prolonged studies of bone growth and reactions. If a fifth marker is needed, mixed injection of tetracycline and Procion H‐8B is recommended. In doses necessary for fluorescence examination, the above recommended substances may be regarded as practically nontoxic. In the dentin, tetracycline and calcein seem to be the best fluorescent markers. Hematoporphyrin is not recommended because of poor labeling properties and general toxicity with weight reduction of the

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01897.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –Biopsy specimens from temporal muscle of denture wearers and subjects with natural dentition were studied by biochemical staining methods. Size and distribution of fiber types were estimated in sections stained for myofibrillar ATPase at pH 9.4. The mean sizes of Type 1,*Type 2 and intermediate fibers in denture wearers did not differ from those of the corresponding types of fibers in subjects with natural dentition. In the denture series. Type 2 fibers were smaller in subjects who rated their dentures as deficient than they were in those whose dentures were good. The frequency of intermediate fibers was low in both series. The mean percentage distribution of Type 2 fibers in specimens from the internal surface of the temporal muscle was significantly lower in the denture series than in the specimens from subjects with natural dentition. It is suggested that the low content of Type 2 fibers in the specimens from the internal surface of the temporal muscle of denture wearers and the small size of Type 2 fibers in subjects who rated their dentures as deficient may be attributed to altered functional demand

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01898.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –The contents of Ca and P in developing enamel of the continuously growing rat incisor were examined by the electron microprobe. A longitudinally sectioned, epoxy res‐in‐embedded maxillary incisor from a 5‐month‐old rat was analyzed by linear scans across the enamel at intervals from the growing end. Near the growing end, concentrations of approximately 2 % Ca and 1 % P were found close to the ameloblast‐enamel junction, increasing to 18 % Ca and 9 % P near the dentino‐enamel junction. With increasing distance from the growing end, a successive increase of the mineral content was observed, together with a leveling out of the concentration gradients from the enamel surface to the amelo‐dentinal junction seen at earlier stages of mineralization. Mature enamel contained about 35%Ca and 17 % P. The results were discussed in the light of previous electron microscopic observations of the same specimen material. It was concluded that in analysis of mineralized tissues in an early stage of development, the mineral content as found by the electron microprobe technique can be considered a valid approximation of the true situation. This technique may also be applied to the study of hard tissues in varying stages of d

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01899.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –The electron microprobe technique was used to study the accumulation of iron in rat incisor ameloblasts as well as the subsequent release of iron from the cells and deposition into the outer layer of the enamel. Starting about 3 mm from the developing end, a gradual accumulation of iron occurred in the ameloblasts. At a stage where the iron content of the cells had reached a maximal level, and the calcium content of the adjacent hard tissue had reached the level of mature enamel, the initial incorporation of iron in the enamel was seen. In the iron incorporation zone the iron content of the enamel increased from less than 0.1 % to about 9 % and the iron content of the ameloblasts was gradually reduced. Concomitant with the increase of iron in the enamel, a decrease of the calcium content was observed in the same region, indicating a withdrawal of calcium from the enamel. Since the incorporation of iron occurs at a stage where the enamel is highly mineralized, the processes involved can hardly be explained as an interaction with the organic matrix. The key to the understanding of these processes should therefore be sought in the adjacent cell laye

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01900.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –The elimination of orthodontically produced hyalinized tissue in the marginal region of the periodontal ligament has been studied with the electron microscope. From a material of 67 rats in which the first molar had been moved buccally with a fixed appliance for a period of 30 min to 28 d, 20 specimens representing experimental periods of 48 h to 14 d revealed that the hyalinized structures disappeared concomitantly with an invasion of cells and blood vessels from the neighboring periodontal ligament. The removal of collagen, cell remnants and degraded vascular elements apparently was mediated by different forms of cellular activity. Breakdown of collagen fibrils was observed around cell processes as well as in inclusions within the cytoplasm of the invading pioneer cells. Penetration of new blood vessels seemed to be an important factor in the elimination of hyalinized tissue. Remnants of cells and erythrocytes were removed by phagocytic activity, while more extensive amorphous masses of vascular components were eliminated by foreign body giant cell activity. Identification of the invading cells has been discussed in relation to current concepts of connective tissue cell differentiatio

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01901.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –Silver and copper amalgams show a pronounced cytotoxic effect on monolayer cultures of human epithelial cells (NCTG 2544). Analyses of the medium from silver amalgam cultures showed that, zinc was released in substantial amounts (14 μg/ml after incubation for 24 h). Small amounts of mercury and possibly also some silver were released, whereas release of copper and tin could not be. detected. Toxicity tests showed that 10 μg Zn2+/ml reduced the number of cells by 96% after incubation for 24 h. In the copper amalgam cultures about. 100 μgcopper and 5 μg, cadmium per ml medium were found after 24 h. Only small amounts of mercury were released, Toxicity tests showed an increasing effect of Cu2+ and Cd2+ with tune. With 50 μg Cu2+/ml the number of cells was reduced by 73% after incubation for 24 h, and after 3 d a similar effect was found with 25 μg/ml. With 10 μg Cd2+/ml no cells were left after 24 h, whereas after 3 d 1μg/ml reduced cell growth by more

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01902.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

ABSTRACT –Plaque samples were examined by double diffusion in agar for the presence of PS L44, a surface antigen ofEubacterium saburreum. The antigen was detected in eight ofnine sampl

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1974.tb01903.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY