ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00353.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00354.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—In the present study serial sections were prepared of 51 human maxillary first premolars. Drawings were made (×150) from each side of the sections. The occlusal angle, the depth and width of the fissure and the thickness of the adjacent enamel were measured on each drawing. The data conformed to a normal continuous distribution and except for the occlusal angle and the depth of the fissure a low or no correlation was found between the different parameters. The results indicate that occlusal fissure of human teeth may not be categorized into specific groups on the basis of morphologic features. The average fissure depth of the individual tooth ranged from 120 to 1,050 μm. The average width in the middle part of the fissure varied between 40 and 156 μm. The average thickness of the enamel at the bottom of the fissure varied between 270 and 1,008 μm and the occlusal angle between 51.6° and

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00355.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—The purpose of this study was to test the retention as well as the caries reduction potential of a fissure sealant under Finnish dietary conditions. The 150 children who served as subjects were selected on the basis of having at least one pair of sound permanent molars. Two hundred first molars, 43 premolars and 119 primary molars were sealed, while the respective tooth from the other side of the jaw was left untreated and used as the control. The findings after 6 months revealed that all 362 sealants persisted. Among the sealants of the first permanent molars, 99% were in excellent condition. All sealants of the permanent premolars and of the primary molars were excellent. Among the permanent control molars 43 (22%) showed carious fissures while among the sealed permanent molars, only 3 (1.5%) had carious fissures. This gives a 93% reduction of the fissure caries. Both the control and the sealed premolars were all sound. None of the sealed primary molars were decayed compared to 7.6% decayed on the control sid

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00356.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—The fluoride release of varnish‐coated silicates and liners and sealants was studied by measuring the uptake of the released fluoride by synthetic hydroxyapatite. Silicate specimens were made and coated with cavity varnish. The specimens were shaken in solution with the apatite for 7 weeks. The apatite was analyzed for fluoride each week and the specimens were then transferred to a fresh solution with new apatite. The varnish reduced the fluoride release during the first three weeks, but after that time the release from the varnish‐coated specimens was the same as that from the uncoated specimens. The release from the liners and sealants was studied by coating composite resin specimens with the material. The resin contained no fluoride. The specimens were shaken in solution with apatite and the fluoride uptake was measured each week in the same manner as for the silicate specimens. The liners showed an initial release of fluoride. When the two different sealants were applied as two layers, only one of the brands showed initial release of fluoride. Five layers of sealant resulted in an initial release from both b

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00357.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—Each of six premolars were exposed to 8 ml of a buffer, pH 5.0. The ionic activity products for FA, HA, CaHPO4, CaF2and Ca4H(PO4)3were determined. It was found that the liquid phase initially was unsaturated with respect to all solid phases and that FA and HA were dissolving from the enamel. Four hours after initiation of the experiments the liquid phase was supersaturated with respect to FA while still unsaturated with respect to HA, which resulted in a precipitation of FA in the enamel and a dissolution of HA from the enamel. Teeth which had been exposed to a buffer unsaturated with respect to both FA and HA exhibited the signs of a natural erosion, while teeth exposed to a buffer supersaturated with respect to FA and unsaturated with respect to HA showed the characteristics of a caries lesion. It was found by analyzing various acidic beverages that these were unsaturated with respect to both FA and HA. By calculation it was found that saliva was unsaturated with respect to HA and supersaturated with respect to FA at a pH of between 5.5 and 4.5. It was concluded that the erosive lesion can be described as the result of a demineralization caused by a liquid phase unsaturated with respect to both HA and FA and the carious injury by a liquid phase unsaturated with respect to HA and supersaturated with respect to F

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00358.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—Pretreatment of the enamel with chlorhexidine did not modify enamel solubility, nor did it interfere with the enamel protective action provided by the fluoride. Oral rinses twice a day with the chlorhexidine‐fluoride solution, pH 5.8, reduced the spread of plaque (Pl I) by 44% and the total plaque mass (total plaque N) by 38% compared with the effect of rinses with distilled water. Rinses with the NaF solution reduced the plaque mass by 41% while the plaque spread remained unaffec

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00359.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—Primary teeth with typical black stain were obtained from 10 children and processed for electron microscopy. The deposit consisted of microorganisms in an intermicrobial matrix of varying density. The majority of the bacteria were Gram‐positive cocci or rods. Calcification of the black stain was observed. The results indicate that this deposit is a special type of dental plaque. It differs from regular dental plaque in that Gram‐positive rods constitute the majority of the bacterial population, and it resembles plaque in its ability to provide a matrix for calcific

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00360.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—Previous clinical studies have shown that chlorhexidine may cause brownish discoloration of tooth surfaces. In a longitudinal periodontitis and caries experiment evaluating the effectiveness of dentifrice as a vehicle for chlorhexidine, the frequency of discoloration has been studied by a microphotometric technique. The present study indicates a definite correlation between brownish discoloration on tooth surfaces and the use of chlorhexidine‐containing dentifrices. Furthermore, the results of this investigation indicate that the discoloration may be influenced by the degree of abrasiveness of the dentifr

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00361.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract—The purpose of the present study was to investigate whether some dental filling materials collect more plaque than others under standardized conditionsin vitroandin vivo. Round disks of the filling materials of silicate, composite and amalgam were prepared and placed on an agar/sucrose medium or hung in liquid medium containing 5% sucrose. The mediae were inoculated withStreptococcus mutansOMZ 176 and OMZ 52–3. After 6 d the disks were rinsed in distilled water and the plaque that had accumulated on the surfaces was scraped off and measured by the orcinol method. The materials were also fitted to acrylic plates and introduced into the mouth. Six patients wore two plates each for comparison of the materials and were told to rinse their mouth every hour with 15% sucrose solution. After 8 h the plaque was scraped off and measured. Silicate disks on agar medium invariably produced inhibition zones of about 4 mm. Composites and amalgam showed no such zones. In liquid medium an insignificant amount of plaque was absorbed to the silicate disks, whereas abundant amounts were found on composite materials and some on amalgam disks. The same trend could be demonstrated in the clinical experime

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb00362.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY