摘要:

Abstract –The ultrastructural features of the epithelial‐mesenchymal interface in a case of an ameloblastic fibro‐odontoma was studied with special reference to possible signs of “inductive” processes. In most parts of the tumor, the odontogenic epithelium was separated from the connective tissue by a thick rim of a finely filamentous mesh work in which a basal lamina was occasionally observed. Mesenchymal cells were seen to touch the filamentous mesh work but no membrane bound matrix vesicles were recorded. Small areas of dentin‐like tissue were found in the juxtaepithelial connective tissue while enamel‐like areas and spherical calcified masses were encountered in epithelial islands. The organic matrix in relation to the enamel‐like tissue consisted of either tubular fibers or a fine‐granular material. It was assumed that the tubular matrix component directed the formation of long enamel‐like crystals, and that the fine‐granular matrix was degraded tubular fibers in which spherical calcified masses might arise. Spherical calcified masses could be found in separate follicles also where they were related to a fine‐fibrillar matrix or collagenous material. The cell layers forming the wall of the islands had a great resemblance to those of an enamel organ, but the findings of dentin‐free, enamel‐like areas are not compatible with the inductive the

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01199.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –0.7 mg/kg VCR was given to nine rats in three experimental groups. Twenty‐three hours after VCR injection the animals were injected with3H‐thymidine. The animals were sacrificed 24, 48 and 72 h after the VCR injection, and by comparison with nine control animals similarly injected with sodium chloride solution and nucleotide, it was shown that VCR causes a delayed migration of pulp cells from the proliferative pool and a small but distinct inhibition of the incisal growth of the incisors. The growth inhibition corresponded to the normal growth over a 24‐h period in nou‐VCR‐injec

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01200.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –0.7 mg/kg VCR was administered intravenously to nine rats in three experimental groups. One hour after VCR injection the animals were injected with3H‐proline. The animals were sacrificed 1.5, 5 and 24 h after the VCR administration, and by comparison with nine control animals similarly injected with sodium chloride solution and3H‐proline, it was shown that VCR causes an early, intracellular retention of labeled proline in the odontoblasts, an abnormal intracellular distribution of labeled material and a generally decreased secretion of dentinal matrix from the odontoblasts in the maxillary incisors. The severity of the effects were shown to vary in different parts of the inc

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01201.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –Anaerobic bacteria belonging to the species Bacteroides melaninogenicus, Bacteroides asaccharolyticus, Fusobacterium nucleatum, Peptostreptococcus anaerobius and Eubacterium alactolyticurn, isolated from necrotic dental pulps, were tested for their capacity to induce neutrophil leukocyte chemotaxis. Generation of chemotactic factors in serum by whole bacterial cells and chemotaxis induced by bacterial extracts were studied in vitro by the Boyden technique. Subcutaneously implanted wound chambers in guinea pigs were used for testing leukocyte migration in vivo. All bacterial strains had a similar high capacity to induce neutrophil chemotaxis. The heavy accumulation of polymorphonuclear neutrophil leukocytes associated with clinical and experimental infections by B. melaninogenicus or B. asaccharolyticus cannot be ascribed to any extreme ability of these organisms to generate chemotactic factor

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01202.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –Lipopolysaccharides (LPS) prepared from one strain of Fusobacterium nucleatum and one strain of Bacteroides oralis were examined for immunological responses in rats. The LPS were applied to the pulp chamber of the two mandibular incisors. Using the plaque forming cell (PFC) method both antigens showed a rapid IgM response in the spleen, and a slower one in the submandibular lymph nodes. In comparison with the IgM response, the IgG response was somewhat slower and weaker for LPS of Bacteroides, while for LPS of Fusobacterium it was hardly detectable. After about 3 weeks both antigens gave a significant antibody titer in serum. The results showed that locally applied antigens of oral microorganisms cam stimulate to an immune response both in the lymph nodes and the spleen resulting in circulating antibodies. The nature of this response is dependent on the chemical characteristics of the LPS‐anti

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01203.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –Implants were prepared by sintering glass‐fibers into a three‐dimensional network with meshes smaller than 20 μm. Oblong 5x2x0.15 mm sheets of the test material were implanted in maxillary incisor alveoli in eight white rats. The alveoli were closed with a suture in the overlying mucosa. After 3 months the animals were sacrificed and sections from the site of implantation prepared. In three animals only root remnants were found but in the remaining five the implants were wholly or partially embedded in bone tissue. Sections studied with transmitted light, microradiography, and scanning electron microscopy showed that mineralized tissue had also formed within the pores of the network. The intimate contact between the individual fibers and the bone within the network was corroborated through microchemical analysis

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01204.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –A study was carried out to analyze the pattern of the age related bone loss in the mandibular cortex and to establish normal values and the observed range of morphometric variables on microradiograms of bone sections taken from a well defined site anterior to and below the mental foramen. Specimens were obtained from 100 Danish subjects with no known systemic bone disease or severe mandibular atrophy. Microradiograms of 100‐μm‐thin undemineralized vertical ground cross‐sections were produced. An electronic point‐counting system was used for the determination of 1) percentage bone mass, 2) mean cortical width (MCW), and 3) the percentage of Haversian canals with resorption surfaces. The analysis showed that cortical porosity and the percentage of Haversian canals showing resorption are unrelated to sex and increased after the age of 50. MCW and absolute bone mass (MCW ×% bone mass) are greater in males than in females and show a parallel age related decrease after the age of 50. Furthermore, the age related increase in cortical thinning and porosity is dependent on the individual as well as on age. Marked individual variation confined the use of these parameters to gro

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01205.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –The aim of the present study was to develop a method for quantitative evaluation of the morphology of inner surfaces of composite resin restorations. Twelve restorations made In vivo using the acid etch technique were examined in a scanning electron microscope at a magnification of × 2000. 2500 predetermined areas (6300 μm2each) on the inner surfaces of the fillings were scored from 0 to 3 with respect to the impression of their rendering of morphologic details from the etched cavity walls. Based on all the scorings and parts of the scorings, estimates for the enamel and for the dentin relief on each of the fillings were calculated. The statistical comparison of these estimates showed that approximately 50 areas per filling might be scored to attain an objective and reliable quantitation of the surface morphol

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01206.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –The present investigations show that there is no correlation between on the one hand the wet and the dry compressive strength of the three gypsum‐bonded investments studied and on the other the compressive strength of the investments at burn‐out temperature. The study also demonstrated that there is no correlation between the compressive strength and the fracture resistance of sharp edges of the investment mold when exposed to the impact of the casting alloy entering the mold. The inconveniences caused by the fracture of such edges are prevented by a moderate rounding of the corresponding parts in the prepar

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01207.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –The present investigation has shown that the setting expansion of two dental stones when measured according to the ADA Specification No. 25, was lower than the expansion determined by a dial gauge method. The values from this latter test and the percentage deviation of the diameter of full crown stone dies (produced in individual silicone impressions) from the base diameter of the original preparation were identical. A reduction of the effective setting expansion to a value of 0.05% or less is desirable and proved possible for the stone materials studied without altering other important propertie

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01208.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY