摘要:

Of 158 carious lesions to be treated with restorations, 66% were found to be without macroscopical cavitation. Observed clinical tissue changes were poorly correlated to accepted standardized radiographic criteria. Thus only 20% of radiolucencies into the amelodentinal junction and 50% of radiolucencies into dentine showed cavities which were confined to the enamel only. Assuming a macroscopical cavity to be indicative of restorative treatment, the present results indicate that a more individualized treatment decision strategy than hitherto is warranted in populations attending comprehensive dental health care.

ISSN:0008-6568    

DOI:10.1159/000260568

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

After five semi-annual applications of two fluoride varnishes, the amount of permanently bound fluoride in the enamel surface was determined in children with lifelong exposure to fluoridated water. The experimental groups consisted of 51 (Duraphat®) and 61 (Fluor Protector®) children aged 13–15 years; and a control group of 71 children of the same age with no history of topical fluoride treatments. 6 months after the 5th semiannual application, in vivo determinations of fluoride content were made on the buccal surface of the upper first premolar using the etching method of Hotz et al. Mean fluoride content at an average depth of 2.9 μm was 3,364 ppm in the Duraphat group, 4,179 ppm in the Fluor Protector group, and 2,036 ppm in the control group. The overall difference between groups was significant (p < 0.

ISSN:0008-6568    

DOI:10.1159/000260569

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Enamel dissolution, Orofax and rat caries studies were carried out to assess the effects of calcium lactate in reducing the cariogenicity of four commercially used candies. When used at the 5% level, calcium lactate was effective in reducing enamel dissolution by as much as 43% in fermenting candy-saliva mixtures. In Orofax studies it reduced the amount of in vitro caries by as much as 87%. In a rat caries study, a test group fed a chocolate caramel candy containing 1.5% calcium lactate produced reductions of 38 and 17% in number and 47 and 31% in severity of smooth surface (buccolingual) and sulcal lesions, respectively, as compared to a control group fed the same candy without additive. These findings plus the fact that calcium lactate is a tasteless, nontoxic chemical compound, commonly used in a number of food products, all indicate that calcium lactate my be considered an effective anticaries food additive.

ISSN:0008-6568    

DOI:10.1159/000260570

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Several dextranase-producing (DP) microorganisms indigenous to ths oral cavity reduce in vitro adherence of Streptococcus mutans to smooth surfaces. In this report, the DP microorganisms were studied to determine if they had an influence on the in vivo S. mutans population and the development of carious lesions in children. The epidemiological investigation showed that the oral cavity of all children sampled harbored dextranolytic microbes and that the highest concentrations were recovered from saliva. Estimates of correlation calculated from the data produced no significant antagonistic relationships between the DP bacteria found in saliva, smooth surface plaque and interproximal plaque and either the DMFS index or the S. mutans population. It was concluded that dextranase-producing microorganisms did not detectably influence the in vivo ecology of S. mutans, possibly because recent evidence indicates a nonglucan molecule may be responsible for initial attachment of S. mutans to smooth surfaces.

ISSN:0008-6568    

DOI:10.1159/000260571

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

In vitro topical applications of acidulated phosphate fluoride (APF) and titanium tetrafluoride (TiF4) were compared in terms of fluoride uptake, penetration and artificial lesion formation. Higher fluoride values were found in the APF-treated halves, but less lesion formation occurred in the TiF4-treated halves. TiF4 applications formed an acid-resistant surface coating which was not removed after a 24-hour washing.

ISSN:0008-6568    

DOI:10.1159/000260572

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Significantly more fluoride was found to be deposited in enamel in vitro from successive applications of acidulated phosphate fluoride (APF; 1.23% F, pH 3.1) and NaF (1.23% F, pH 7.5) than from APF alone. When the effect of these treatments to both sound enamel and initial lesions was compared using an artificial caries system, no differences were found in either histological appearance or depth between the resulting lesions. It would appear that there may be an optimal level of fluoride uptake beyond which no additional benefit is gained.

ISSN:0008-6568    

DOI:10.1159/000260573

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The aim of this study was to determine whether the extent of an initial artificial caries-like lesion was related to its rate of progress after two applications of APF (1.23% F) and exposure to artificial saliva during lesion formation in vitro. Treatment of small lesions (mean depth 65.7 μm) resulted in their reversal or arrest while the same treatment of larger ones (mean depth 127.4 μm) did not prevent their progress despite evidence of some remineralisation. This suggests that the caries inhibitory effect of fluoride is optimal in the small, early lesio

ISSN:0008-6568    

DOI:10.1159/000260574

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The arrangement of microcrystallites in human deciduous enamel was studied by electron paramagnetic resonance using a stable CO33––radiation centre as a probe. Enamel samples taken from maxillary central deciduous incisors showed a lower degree of crystallite arrangement as compared with samples taken from permanent incis

ISSN:0008-6568    

DOI:10.1159/000260575

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

In this study the adsorption of two fluoride-containing polyelectrolytes with different hydrophobic properties on hydroxyapatite is investigated. It was found that the adsorption of the macromolecule was accompanied by the uptake of fluoride, but at a higher rate and with higher amounts than the polymer itself. The influence of the polyelectrolytes on the surface properties of hydroxyapatite and whole enamel was investigated by zeta potential determinations and contact angle measurements, respectively. It was observed that adsorption of very minor amounts of these macromolecules had a remarkable effect on the zeta potential of hydroxyapatite. The original zeta potential of ––9 mV was increased to relatively high positive values. Furthermore, adsorption of the most hydrophobic polymer on the enamel resulted in a poor wettability of the surface by water. Contact angles around 90° were observed, indicating the hydrophobic character of the treated sur

ISSN:0008-6568    

DOI:10.1159/000260576

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The fluoride uptake from two polyamine fluorides by human enamel was studied as a function of treatment time, concentration and pH of the polyelectrolytes. The two polyamine fluorides were hydrophilic and hydrophobic in character, respectively. The fluoride concentration at various distances from the anatomical surface of enamel was measured by an acid etch technique using dilute 0.02 and 0.1 M perchloric acid solutions. Fluoride contents up to 45,000 ppm were observed at the outermost enamel layer. Increasing fluoride contents were observed at relative low pH values and longer treatment time. The hydrophilic polyamine fluoride deposited more fluoride as compared to the hydrophobic polymer. The influence of the polymer concentration on the fluoride content of enamel was not significant. The fluoride-containing polyelectrolytes investigated have a pronounced effect on the acid solubility of human enamel as compared to APF topical solutions. Reduction in acid solubility of about 30% was observed in solutions with pH values of about 1.

ISSN:0008-6568    

DOI:10.1159/000260577

出版商:S. Karger AG    

年代:1982

数据来源: Karger