摘要:

The effect of periodic treatment with synthetic saliva and sodium fluoride on initiation and progression of caries-like lesions of enamel using a single-section technique and polarized light microscopy was studied. The results indicated that periodic treatment with synthetic saliva and sodium fluoride rinses decreased the mean depth of the bodies of the lesion to a significant extent and reduced lesion formation rates during both the lesion initiation period and lesion progression period. Fluoride pretreatment followed by a 24-hour synthetic saliva rinse reduced the depth of lesion formation significantly when compared to synthetic saliva rinsing alone. The findings in this study imply that frequent application of relatively low concentrations of fluoride limits the progression of enamel caries to a significant extent.

ISSN:0008-6568    

DOI:10.1159/000260886

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

A new apparatus for the de- and remineralization of enamel in vitro under constant composition conditions is described. A de- or remineralizing solution flows over the specimens at a controlled rate. During artificial lesion formation (using an acetate buffer containing methylhydroxydiphosphonate, MHDP), the composition of the solution is constant. The Ca and phosphate variation is less than 3%, pH variation is less than 0.03 pH unit. For enamel these variations are within the biological variations between enamel specimens. Experimentally it was found that the liquid streaming over the enamel surface does not measurably remove material from the surface (erosion) with the experimental error of 0.1 μm. This was measured by following microhardness indentations during demineralization. The effect of various MHDP concentrations on demineralization was investigated in the range of 2–50 μM. Even low concentrations of MHDP prove to be effective in the microhardness increase and lesion depth reduction during demineralization. In the demineralization experiment it is shown by means of microradiography, hardness measurements as well as light microscopy that the method described quickly produces reproducible lesions. In a remineralization experiment of demineralized enamel effective remineralization of the lesions occurs in 360 h, giving a threefold increase in microhardness and a twofold decrease in lesion de

ISSN:0008-6568    

DOI:10.1159/000260887

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Three micromethods for the estimation of Streptococcus mutans and lactobacilli were compared. A micropipette method was selected because of its ability to detect low levels of the organisms and its high agreement with the conventional plating method and efficient use of agar medium. The trypticase yeast cystine sucrose bacitracin agar was found to be superior to the mitis salivarius bacitracin agar. Stimulated saliva of 144 Tanzanian children from the rural and urban areas in Morogoro was investigated for S. mutans and Lactobacillus counts. Both organisms were observed in all Tanzanian children. The mean S. mutans and Lactobacillus counts were 5.0 ± 0.9 and 4.5 ± 0.9 log cfu/ml saliva, respectively. S. mutans counts greater than 106 cfu/ml saliva were observed in 25% of the urban children and in 5% of the rural children. The caries prevalence was rather low and weakly correlated with the S. mutans and Lactobacillus counts. The Tanzanian children with a high S. mutans count but with a low caries experience were considered as caries-inactive at present, but at risk of developing dental caries by changing dietary habit

ISSN:0008-6568    

DOI:10.1159/000260888

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260889

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260890

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260891

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The aim was to determine at what ages the different types of human permanent teeth are susceptible to development of fluorosis. The prevalence of disturbances of enamel mineralization was recorded blindly in 70 children who had previously participated in a fluoride tablet program (0.5 mg F–– per day) and 40 other children who had never received fluoride tablets. Comparison of the prevalence of enamel lesions between these two groups and between the ages at which children began to take the tablets revealed the ages at which there was an increased risk of fluorosis. The data showed that fluoride can affect teeth late in their development when enamel is in a stage of late secretion or early maturation. It was concluded that this finding, which is in accordance with experimental animal studies, calls for a fundamental change in thinking not only with respect to the mechanisms involved in human enamel fluorosis, but also in relation to timing of fluoride progr

ISSN:0008-6568    

DOI:10.1159/000260892

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

This paper describes the effect of xylitol and fluoride on remineralization of surface softened human enamel in vivo. Surface softened enamel blocks were mounted in the lower prosthesis of 20 full denture-wearing participants. These participants used xylitol- and/or fluoride-containing toothpastes during 4-week periods. Knoop hardness measurements were employed to estimate the degree of remineralization in each period. After 26 days of toothpaste use it was found that the enamel defects were rehardened substantially and that the hardness of sound enamel was approached. The changes of enamel hardness were not significantly affected by the presence of xylitol and/or fluoride in the toothpastes.

ISSN:0008-6568    

DOI:10.1159/000260893

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The pH of human dental plaque following ingestion of five reference foods was monitored for 120 min in 4 subjects using an interdental metal-metal oxide touch microelectrode concurrently with a glass indwelling interproximal electrode mounted in a removable acrylic partial denture. Time that pH remained under given values, and time-pH unit area under these lines provided more separation among foods than did minimum pH or pH drop. Data obtained after 60 and 120 min gave similar results in terms of significant ordering of reference foods for the touch, but not the indwelling electrode system. The indwelling system detected a significantly greater magnitude and duration of pH fall after ingestion of all foods. However, ordering of and discrimination between pH falls induced by the foods was similar in both electrode systems.

ISSN:0008-6568    

DOI:10.1159/000260894

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Three patients with a partial natural dentition in one jaw and a full denture in the other participated in this study. Enamel treated with APF gel, Duraphat or Fluor Protector and untreated controls were positioned in a full denture for periods up to 3 months. Plaque accumulation on the enamel blocks was evaluated by scanning electron microscopy. The results show that in all 3 patients studied the formation of CaF2 inhibited dental plaque accumulation.

ISSN:0008-6568    

DOI:10.1159/000260895

出版商:S. Karger AG    

年代:1985

数据来源: Karger