摘要:

abstract–The morphology of pellicle formation was studied using correlated transmission and scanning electron microscopy. Pellicle developed on hydroxyapatite/epoxy resin splints attached to the buccal surfaces of molars and premolars in six young individuals. Splint segments were removed at intervals of2, 4, 6, 12, 24, and 48 h. Measurements of pellicle thickness revealed that during the first 12 h considerably more material formed on the apatite surfaces than on the epoxy resin areas of the splints. This difference was equalized in 24‐ and 48‐h specimens. Three types of pellicles could be distinguished on the basis of morphologic criteria. A globular pellicle., characterized by a consistent presence of globules of varying size and configuration, seemed to predominate in most subjects. These globules could not be mistaken for bacteria due to their dimensions, contour, and lack of cell walls. A fibrillar pellicle consisted of 3‐ to 7‐nm‐wide fibrils and frequently included some finely globular particles. A granular pellicle displayed a relatively even surface contour and did not exhibit globular or fibrillar structures. In contrast to the two other types, the granular pellicle contained distinct laminations. Apparently, the varying morphology of the early pellicle is a reflection of its complex chemical

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00556.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–Odonotogenesis of the 2nd premoiar begins in the majority of cases at the age of 3–31/2years, although this period can vary more widely than that for other permanent teeth. For this reason, aplasia of this, group of teeth cannot be diagnosed as early and with the same degree of certainty. A group of 104 children aged 3–7 years in whom one or more tooth germs mesial to the 1st permanent molar were not visible in the various age groups was reexamined radiographically in the region where they apparently lacked the development of tooth germs. The second examination tools place 16–24 months after the first, and a comparison was made of the two examinations. The study confirms that the 2nd premoiar can be very late in developing and that the chance of this being so is greater in the maxilla than in the m

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00557.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–A sulfated glycoprotein was demonstrated in 2‐h pellicle material collected from monkeys. Furthermore, a sulfated macromolecule present in plaque extracts was identified as a sulfate glycoprotein by electrophoresis on cellulose acetate strips. The present data indicate that acidic proteins are selectively adsorbed to tooth surfacesin. v

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00558.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–A35S‐labeled sulfated glycoprotein was isolated from rabbit submandibular glands. Acid stability studies on the35sulfate groupings present in the intact glycoprotein gave a half‐life of 45 min. Partial acid hydrolysis of the35S‐labeled glycoprotein in 0.1 M HCl for 90 min at 100°C liberated a radioactive fraction which was free from peptide and fractionated in the monosaccharide range of a Sephadex G‐15 column. Examination of this fraction by paper chromatography revealed the presence of a major component having the characteristics of N‐acetylglucosaminc 6‐0‐sulfate and a minor component having the properties of N‐acetylgalactosaminc 6‐0‐sulfate. The presence of ester sulfate groups in the intact glycoprotein was confirmed by

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00559.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–The roll tube culture technique was utilized to examine quantitatively and qualitatively the predominant cultivable microflora inhabiting the clinically healthy gingival sulcus. Seven periodontists aged 32–54 years were included in the study. From a total of 350 isolates, 85 (24.3%) were obligate anaerobes, 53 (15.0%) were Gram‐negative, and 197 (56.3 %) were categorized as rods. Actinomycetes predominated in three samples. Four samples were dominated byStreptococcusspecies. The flora as revealed in the present study comprised a markedly lower proportion of Gram‐negative organisms than that found at the base of deep periodontal

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00560.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–The susceptibility to chlorhexidine of bacteria in aerobic, facultatively anaerobic and anaerobic isolates from clinical specimens of wounds, urine, saliva, and dental plaque was studied. Agar diffusion tests using 50 μg chlorhexidine discs and agar dilution tests were performed and the MIC values correlated with inhibition zone diameters, Anaerobic plaque strains were isolated and tested by the agar dilution method in an anaerobic glove box. Regression lines obtained for five agar media demonstrated a good correlation between zone diameters and MIC values. There was a broad range of susceptibility to chlorhexidine among both Gram‐positive and Gram‐negative strains. Low MIC values were noted for staphylococci,S. mutans, S. salivariusandE. coli, while strains ofProteus, PseudomonasandKlebsiellawere less susceptible.S. sanguisshowed intermediate susceptibility with both low and high MIC values. Among the anaerobic isolates tested, the strains most susceptible to chlorhexidine werePropionibacteriumandSelenomonas, while the least susceptible strains were Gram‐negative cocci resemblingVei

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00561.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–Cadmium, zinc, copper, and mercury, being components of dental alloys, have been tested at concentrations from 20 to 120 μM for their effect on the incorporation of14C‐proline into various fractions of rabbit dental pulp incubatedin vitro. With cadmium and zinc anincreasedamount of14C‐activity was recovered from the TCA‐soluble pool, whereas the further incorporation into total protein and collagen, i.e.14C‐hydroxypraline, was markedly inhibited. Copper and mercury, however,reducedthe amount of label in the TCA‐soluble fraction. Both metals exhibited a dose‐dependent inhibitory effect on the hydroxylation step in collagen synthesis, whereas for mercury only, an inhibition of the general protein synthesis was indicated. With all four metals the proportion of14C‐labeled protein and hydroxyproline recovered from the medium was reduced, the effect being most prominent with

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00562.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–Lipopolysaccharides (LPS) prepared from a strain ofBacteroides oralis, a strain ofFusobacterium necrophorum, and a strain ofF. nucleatum, all isolated from an infected root canal in monkey (Macaca cynomolgus), were examined for endotoxic activities using primary skin reactions in rabbits and induction of leukocyte chemotaxis in rats. LPS ofB. oralisshowed considerably lower ability to cause skin inflammation than LPS of the fusobacteria. However, the leukotactic effect of the LPS preparations as determined by the wound chamber method in rats was approximately of the same proportion. In both tests the reactions were compared with those of commercial LPS ofSalmonella typhi. This study shows that endotoxic LPS can be isolated from oral Gram‐negative bacteria, which have infected the root canal. Therefore LPS. may play a role in the development and maintenance of chronic inflammation of the periapical tiss

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00563.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–The lipid pattern and the fatty acid composition of human oral epithelium were studied qualitatively and quantitatively with the aid of thin‐layer chromatography and gas‐liquid chromatography. The material studied consisted of scrapings from the mucosa of the hard palate of nine cadavers and of three volunteers. Two methods for collecting the material were used: A) the epithelium was isolated by the removal of sub epithelial connective tissue from the connective tissue side and B) the epithelium from the epithelial side was carefully scraped off. The lipid pattern of the epithelium was dominated by cholesterol (25 mol %) and phosphoglycerides (total 45 mol %), while triglycerides and free fatty acids constituted 10—15 mol % each. The fatty acid compositions of the lipids were remarkably similar to each other, although the specific characteristics, of each Individual lipid were still noticeable. All lipids showed a large proportion of linoleic acid and a relatively small proportion of other polyunsatured fatty acids. In several respects the lipid pattern and the fatty acid composition of the epithelium were similar to those found in other ectodermal tissues, but they exhibited a number of differences from the corresponding pattern of the rnesenchymal connective

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00564.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

abstract–The cytotoxicity of fresh and 1‐day‐old silicate cement, composite restorative material and zinc oxide‐eugenol cement (ZOE) was tested using human epithelial cells (NCTC 2544) in four different cell culture systems: (1)5.1Cr‐release from prelabeled cells after incubation for 4 and 24 h in the presence of the materials, (2) Implanting the materials on an agar overlay and visualizing any cytotoxic effects after 24 h by neutral red vital stain. (3) Cell growth during 5 d in the presence of the materials7hellip; (4) Colony‐forming ability after exposure of the cells for 30 min to medium previously incubated with the materials for 24 h. Freshly prepared and 1‐day‐old ZOE exhibited a prominent cytotoxic effect in all four systems. A less marked effect was found for the composite material in systems 2, 3, and 4, while silicate cement appeared to be the least toxic material in these three systems. Neither silicate cement nor composite showed any cytotoxic effect in system 1 based on51Cr‐release. It is concluded that the effects obtained by the cell culture techniques did not mimic the reactions obtained when the materials are tested under conditions which reflect t

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1977.tb00565.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY