摘要:

abstract–Molar tooth germs from 17‐d‐old mouse embryos were cultivated in a Trowelltype culture, and different culture media were tested for their ability to support enamel formation. The medium which allowed secretion of considerable amounts of enamel matrix by ameloblasts consisted of BGJb medium supplemented with 20 % horse serum, 10 % chick embryo extract and 0.9 mM ascorbic acid. At the onset of culture the teeth were in the early bell stage. After 2 weeks of cultivation both odontoblasts and ameloblasts had differentiated, and considerable amounts of predentin and enamel matrix had been secreted. Similar development was also seen in teeth which had been enzymatically separated into the mesenchymal dental papilla and epithelial enamel organ and subsequently recombinedin vitro. This method allows good differentiation of odontogenic tissues, and is considered suitable for further studies of tissue interactions in the tooth rud

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00503.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–The water permeability of the human palatal mucosa has been studied in 12 persons with 1 year of full maxillary denture experience and 10 persons without dentures. Transmucosal water transport rates were studied gravimetrically with the use of solutesaturated discs of filter paper in contact with the mucosa, in accordance with earlier described procedures (Kaaber1973a, b). The inflow of water through clinically healthy mucosa was at the same level in both groups. After use of a 1.10 mol sucrose solution a significant increase in the inflow was observed in the denture wearers group, which suggested an increased amount of osmolytes in the mucosal surface. Two denture wearers with a slightly inflamed mucosal surface showed an increased inflow after use of water and a corresponding strong outflow after use of the sucrose solution, indicating a partial loss of the mucosal barrier functio

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00504.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–Salivary mucins can aggregate oral bacteria and are also constituents of pellicle and plaque. A, B, and H blood group antigens are present on the mucins of secretors only. These mucins have also been shown to contain more carbohydrate than non‐secretor mucins. The aim of the present study was to relate these genetically determined differences in mucin composition to caries prevalence. Data on blood group, secretor status, and caries prevalence was collected from 69 dental students. In all blood groups, the average caries prevalence was lower for secretors than for non‐secretors. The difference was more pronounced for smooth surface than for total surface prevalence. The secretors of blood group mucin A had the lowest caries prevalence. The results would be consistent with an impact of the mucin composition upon the caries prevalence, and possible mechanisms are disc

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00505.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–In carious lesions adjacent to silicate or amalgam restorations outer lesions of the cementum showed the same content and distribution of Ca, P, Mg, and S as did primary lesions in this area, but differed from these in having an increased content of Zn., Al, and probably F (silicate cases) and Zn, Sn, and Cu (amalgam cases). The cementum walls showed an uptake of ions largely similar to that previously described in dentinal wall

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00506.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–The relative effects in human dental plaque material from the three main extracellular sucrolytic enzymes from bacterial origin, invertase, dextransucrase and levansucrase, have been investigated by means of quantitative determination of products with sucrose as the substrate. Twenty young men having carious lesions and harboring plaque material on the tooth surfaces, were selected. One gram (wet weight) of plaque material was obtained and divided in five samples, 0.2 g each, for different investigations and controls. Twice as much fructan as glucan was found in plaque. Invertase activity was found to dominate sucrolysis within plaque with 99.67 % of the total activit

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00507.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–The study was undertaken to evaluate the antimicrobial effect of a commercial toothpaste, claimed to contain active chlorhexidine gluconate. Two traditional toothpastes and a 0.5 % chlorhexidine gel were used as negative and positive control pastes. To exclude the effect of mechanical cleaning, all the agents were applied twice daily to the tooth surfaces by means of individually constructed acrylic cap splints. Ten dental students used each paste in a 4‐week cross‐over double‐blind study comprising four test periods of 4 d duration. The students were allowed normal mechanical oral hygiene during the 3 d between the test periods. At the beginning and the end of each test period the tooth surfaces in the right halves of the jaws were scored for the Plaque Index, after which disclosing solution was used and the teeth of the left halves of the jaws were scored for stained plaque. Of all the toothpastes tested, only the chlorhexidine gel exhibited an antimicrobial effect comparable to that of efficient mechanical oral hygiene measures. The effect of the toothpaste with claimed chlorhexidine content did not differ from that of the two traditional toot

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00508.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–The effect of surface sealing and presence of bacteria in connection with pulpal response to silicate cement and composite resin restorations was tested in monkey teeth. Surface‐sealing of silicates reduced the pulpal reactions to this material, whereas no such effect was observed when composites were sealed. Bacteria regularly occurred on the cavity walls except underneath zinc oxide/eugenol (ZOE) fillings and when silicates were sealed with ZOE. The frequency of bacteria was higher in teeth with unacceptable pulpal responses (44 of 49) than in teeth with acceptable reactions (48 of

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00509.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–The addition of amine fluorides to a copal resin (Copalite®) and a chlorine caoutchouc varnish (Pergut S‐40®) has been studied. The permeability of Copalite films was only slightly increased whereas the excellent film‐forming qualities of Pergut S‐40 were destroyed by the addition of fluorides. A high fluoride release was found initially from test films of the materials but within 2–3 weeks a decrease to very low fluoride levels w

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00510.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–The purpose of the study was to determine the uptakein vitroof fluoride from restorative materials by tooth ename1 and whether prior etching of the ename1 causes a change of uptake. The outermost layer of the labial surface of extracted canines was removed by grinding and the enamel was covered with five different fluoride‐containing materials; a silicate, a composite resin, an amalgam, a silicophosphate, and a polycarboxylate luting cement. The material was either removed immediately or after storing the tooth in distilled water. The fluoride content was determined using a sensitive physical method based on the19F (p, αy)16O reaction. In addition, the fluoride content of enamel after etching for different periods of time and of etched enamel which had been in contact with silicate cement was determined. The mean fluoride content of uncovered interior ename1 was 226 parts/106. All materials, except the composite, increased clearly the fluoride content of the underlying enamel. Etching of interior enamel also increased the fluoride values. No difference could be shown in fluoride uptake from silicate and composite resin between etched and unetched en

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00511.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract–The aim of this work was to determine the quantity of remaining unreacted methacrylate groups in polymerized dental sealants. Eight brands of sealants were investigated by means of a grating infrared spectrophotometer. The infrared absorbance measurements were made before polymerization and repeated after the sealants had been polymerized at 37°C for 24 h. 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 results demonstrate that commercially available sealants exhibit different degrees of conversion 24 h after the start of polymerization. The quantities of remaining methacrylate groups after polymerization under conditions comparable with optimal clinical conditions range from approximately 15 % to approximately 35 % in the different bran

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00512.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY