摘要:

An attempt has been made to develop a technique for the serial sampling of porous enamel, mesenchymal tissues, ectopic mineral deposits, developing tissues and other material not amenable to the established technique of sampling by acid etching. The samples are removed by abrasion and the layer thickness of the samples measured using a Mikrokator. The determination of fluoride distribution across various tissues has been used to illustrate the scope of the method.

ISSN:0008-6568    

DOI:10.1159/000260835

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

In fitting enamel biopsy data to a curve that describes the F profile in a subset of individuals subjected to a given treatment regimen, an implicit approximation is made that all individuals of a subset have the same F profile. In the present work we assume that the F profiles for the individuals can be best described by a single polynomial functional form, and that the coefficients of the polynomial can be calculated for each individual from multilayered biopsy data. The F content at a normalized depth can then be calculated for each individual and be used to compute the mean F content of the subset. Our principal objective here has been to compare statistically the suitability of 21 polynomial functions in fitting multilayered biopsy data. A function, log F = [a0 + a1log X + a2(log X)2 + a3(log X)3] + log[a1 + 2a2log X + 3a3(log X)2 + 1], where F and X are enamel F content and depth, respectively, was found to describe the F gradients with a mean standard deviation from regression below the level of analytical errors expected in biopsy data. The profiles are used both to interpolate and extrapolate the F contents of the specimens at standardized depths. This procedure should increase the precision and decrease the cost of clinical F biopsy studies.

ISSN:0008-6568    

DOI:10.1159/000260836

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Raman spectra of octacalcium phosphate, sodium monofluorophosphate and aqueous monofluorophosphate solutions were obtained, some at temperatures as low as 40°K. The internal modes of phosphate and monofluorophosphate (PO3F2––) moieties in these materials were compared with each other and with previously reported spectra of carbonated apatites and dental enamel. Octacalcium phosphate could be identified from apatite by differences in the phosphate bands of their Raman spectra. Monofluorophosphate ions, either located in a crystal structure or in aqueous solution, could be easily distinguished from phosphate ions using Raman spectros

ISSN:0008-6568    

DOI:10.1159/000260837

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Artificial caries lesions were implanted in the partial dentures of 10 subjects and treated for 2 weeks by brushing in vivo with a monofluorophosphate (MFP®) dentifrice, a similar dentifrice containing CaCl2, or a placebo. Analysis of the lesions for fluoride showed that both MFP dentifrices deposited significant fluoride in the enamel, but that the MFP: CaCl2 dentifrice was significantly better than the MFP dentifrice

ISSN:0008-6568    

DOI:10.1159/000260838

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Blocks of human enamel containing artificial caries lesions covered with Dacron mesh were implanted in the dentures of 14 subjects. Each subject, according to random design, was instructed to brush his/her teeth, with their denture in place, three times daily for 2 months using a sodium monofluorophosphate-dicalcium phosphate dihydrate (MFP/DCPD) dentifrice or a placebo dentifrice containing no fluoride, soluble calcium or phosphate. Every subject used both dentifrices in a crossover, double-blind design. Matched pairs of enamel blocks with artificial lesions were used, one of which was treated with a dentifrice and one kept untreated as a control. Statistically significant remineralization as determined by several parameters occurred in the artificial lesions treated with both the MFP/DCPD and the placebo dentifrices (p < 0.01). The MFP/DCPD dentifrice treatment reduced the depth of the lesion 19% which was significantly more (p < 0.01) than the placebo group (––3.

ISSN:0008-6568    

DOI:10.1159/000260839

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The ability of cooked starch (CS) and raw starch (RS)to cause intraoral enamel demineralization was determined by the iodide permeability (Ip) test which registers demineralization of enamel by an increase in Ip (+ΔIp) and mineralization by a decrease in Ip (––ΔIp). 5 subjects, who wore a palatal prosthesis holding 8 bovine enamel blocks covered by a layer of Streptococcus mutans swished 15 g of a 10% jelly of CS or 15 ml of a suspension of RS in the mouth for 1 min, and the change in Ip was determined after a period of 45 min. The salivary clearance of maltose during the experiment was also determined. CS gave + ΔIps which were statistically significant in 2 of the 5 subjects. The mean ± SE was +3.6 ± 1.47·10––10 M of I, indicating mild demineralization. RS gave ΔIps in 4 of the 5 subjects (mean ––6.7 ± 1.87). The rate of salivary clearance of maltose varied considerably among the subjects but CS consistently showed higher initial concentrations than RS. Maximal salivary maltose concentrations ranged from 1,920 to 3,052 mg% for CS and from 523 to 1,041 mg% for RS. The range of the clearance time was from 19.3 to 44.9 min for CS and from 14.7 to 48.2 min for RS. Plotting maltose concentrations against time gave curves which followed an exponential equation. The areas under the curves were calculated, and correlation with the respective Δlps gave r = 0.78. It was concluded that RS had no demineralization potential, and that the demineralizing ability of CS was related to rapid hydrolysis and high early concentrations of maltose in saliva, and unrelat

ISSN:0008-6568    

DOI:10.1159/000260840

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Single i.p. fluoride (F) injections were given to rats that were sacrificed 15, 35, or 70 days later. The doses were 0, 0.75, 1.5, 4.0, 7.0, or 14.0 mg F/kg. Plasma F and calcium levels had returned to within or near the range of control values within 24 h following the F doses. At 15 days after the doses, the mandibular incisors of all F-injected groups showed microradiographic evidence of fluorosis and the phosphorus levels of the developing enamel were reduced in groups with F doses of 4.0 mg/kg or more. The visual disturbances in enamel mineralization tended to disappear with time so that, by 70 days, only the partially mineralized enamel of the 14.0 mg/kg group remained adversely affected. These findings indicated that disturbances of enamel mineralization interpreted as fluorotic can occur in the absence of elevated systemic plasma F levels. It is hypothesized that the gradual release of F from the adjacent bone establishes locally high F levels in the vicinity of the developing teeth and that these high local levels are sufficient to cause enamel fluorosis.

ISSN:0008-6568    

DOI:10.1159/000260841

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260842

出版商:S. Karger AG    

年代:1985

数据来源: Karger