摘要:

An optical instrument is described which quantitates incipient smooth surface caries lesions in vivo. The possible role of such quantitation in caries management and in clinical caries research is discussed. The instrument uses a bundle of small fibres in an ‘optical needle’ with a flat end that is placed on the lesion. Half the fibres are used to illuminate the lesion and the other half to collect the light backscattered by the lesion interior. In this geometry, lesions reflect much more light than does sound enamel. The instrument has been validated against natural lesions in extracted teeth, and the depth of these lesions and their mineral loss were measured by microradiography. The correlation coefficient between these two parameters was 0.96 and the correlation between optical measurement and lesion depth 0

ISSN:0008-6568    

DOI:10.1159/000261117

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Tooth sections were treated in vitro for 4 min with APF, SnF2, or received no treatment. Each treatment group then received washes of KOH, (24 h), an inorganic solution (24 h), or DDH2O (2 min) and were placed into dialyzed 15% w/v gel (pH 4.3) containing 0.15 mM hydroxyapatite, but no fluoride (< 0.02 ppm F). Adjacent nontreated sound enamel acted as the control. Lesion microdissection, after 2 weeks exposure to the acidified gel, revealed an inverse relationship between lesion body fluoride concentration and lesion depth. The lesion depth was smallest, and the lesion body fluoride concentration was greatest in both fluoride-treated groups after a 2-min DDH2O wash, a 24-hour inorganic wash, and a 24-hour KOH wash, respectively. These data support the theory that the progress of carious lesions is related to the fluoride concentration in the lesion and that the fluoride concentration in the lesion is related to the acquired fluoride concentration in sound enamel.

ISSN:0008-6568    

DOI:10.1159/000261118

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Boiled sweets formulated with Lycasin® were compared with conventional sugar-base sweets. Incubated in media containing solutions of the sweets, mixed cultures of oral microorganisms produced less polysaccharide and acid, with significantly less demineralizing action on dental enamel and hydroxylapatite, from the Lycasin than from the sugar-base products. In comparison with these differences, the effects of changing the flavouring acid combinations in the sweets were minor, but levels of citric and malic acids as high as 1.00% showed some inhibition of the activity of the oral microorganisms

ISSN:0008-6568    

DOI:10.1159/000261119

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Lycasin, its parent glucose syrup, maize starch and sorbitol were subjected to the action of a specific amyloglucosidase at 37 °C, and samples were analysed at set intervals for D-glucose and total reducing sugars. Glucose syrup was hydrolysed rapidly and completely to D-glucose, but Lycasin produced only 40–50% as much, and D-glucose production ceased after the first 2–4 h. Dimers of linked D-glucose and sorbitol units remaining after degradation of the Lycasin oligosaccharides were cleaved at a much lower rate by the amyloglucosi

ISSN:0008-6568    

DOI:10.1159/000261120

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The bactericidal efficacy of metronidazole against bacteria in carious dentin was clarified by measuring (1) the difference between bacterial recovery from suspensions of carious dentin on metronidazole-containing BHI-Blood agar plates (10 μg/ml) and control plates and (2) the difference between bacterial recovery from carious lesions of freshly extracted teeth, covered by α-tricalcium phosphate (TCP) cement containing metronidazole (5%) for 1–3 days and that covered by TCP only. More than 103 bacteria per milligram sample were recovered from carious dentin. More than 99% of the bacteria were, however, not recovered when samples were inoculated on metronidazole-containing BHI-Blood agar plates or when the lesions were covered by TCP cement containing metronidazole, indicating that metronidazole effectively disinfected the carious den

ISSN:0008-6568    

DOI:10.1159/000261121

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Ultrastructure, growth, and adherence to hydroxyapatite of Streptococcus mutans ATCC 27351 was studied after treating bacterial suspensions for 1 h with 0.1 % chlorhexidine gluconate (CHX), 0.1 % sodium fluoride (F), or a combination of these two (CHX + F). Cells treated with 0.1 M phosphate-buffered saline were used as controls. Electron microscopy revealed that the treatment with CHX or CHX + F caused disruption of streptococcal cells with vacuolization and sloughing and leakage of cytoplasmic constituents. The F-treated specimens appeared the same as the controls, where the ultrastructure was mostly normal. In the adherence assay, radiolabelled bacteria attached themselves in 77.9% to hydroxyapatite in the control series. Treatment with F reduced the adsorption to 63.7%, and treatment with CHX and CHX + F to 57.4 and 43.4%, respectively. The reduction in CHX and CHX + F series when compared with the controls was statistically highly significant. The synergistic effect of CHX and F was further verified in minimum inhibitory concentration titrations where total inhibition was observed at 0.5% F and 0.1% CHX, respectively, while CHX + F inhibited growth at 0.05%. Thus, F does not interfere with the toxic effect of CHX on S.mutans cells, but, on the contrary, the two chemicals seem to exert a synergistic mode of action.

ISSN:0008-6568    

DOI:10.1159/000261122

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Lycasin® was included in diets fed to caries-active Osborne-Mendel rats for periods up to 8 weeks. The animals could tolerate up to 15–16% of Lycasin in dry-powder diets and up to 25% in pelleted diets before gastro-intestinal disturbance. Lycasin 80/55 at 25% in the diet was non-cariogenic, producing a very low level of caries, similar to that on a maize starch regimen and significantly below that on a sucrose regimen. At 16% in the diet D-sorbitol was even less cariogenic than Lycasin. Compared with the sucrose control, the reductions in caries scores were 89% on the sorbitol and 72% on the Lycasin 80/55 regim

ISSN:0008-6568    

DOI:10.1159/000261123

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Forty-eight Sprague-Dawley rats were divided into four groups. Two groups were injected daily with saline (groups 1 and 2) and two groups with isoproterenol (0.5 mg/kg body weight, groups 3 and 4) beginning at the age of 21 days. Groups 1 and 3 were each day fed nine subsequent sucrose-containing meals followed by eight starch-containing meals. Groups 2 and 4 were fed alternating sugar- or starch-containing meals, totally 17 meals per day. The animals were sacrificed after 14 weeks. At the end of the experiment, the animals in the isoproterenol groups had higher body weights. Caries development increased significantly after isoproterenol treatment. The diet regimen with alternating sugar- or starch-containing meals increased caries development, particularly in combination with isoproterenol treatment. Using low cariogenic conditions, we found that an unspecific β-agonist (isoproterenol), given posteruptively at a low dose, enhances caries development

ISSN:0008-6568    

DOI:10.1159/000261124

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

This paper deals with enamel and root surface demineralization under plaque in vivo as a function of time. The enamel was demineralized using the Øgaard method in which preformed orthodontic bands are attached to the premolars in situ for 4, 6, and 8 weeks; a niche in the bands is responsible for plaque accumulation. In a second experiment cement-covered root surfaces (and enamel) were mounted on a removable appliance (Hawley retainer). Also in this case an orthodontic band was placed over the samples to create a space for plaque accumulation of about 0.8 mm between sample and band. All samples were analyzed by means of microradiography. The results show that (1) demineralization of enamel with the Øgaard method and using the Hawley retainer gives values for lesion depth and mineral loss that are statistically not significantly different; (2) lesion progress and mineral loss in vivo is about 2.5 times faster in roots than in enamel; (3) the demineralization in enamel is roughly linear with time, and (4) roots demineralize in vivo very fast during the 1st week and much more slowly there afte

ISSN:0008-6568    

DOI:10.1159/000261125

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The total fluoride concentration in unstimulated whole saliva was measured before and at selected intervals after a self-applied 1.1% neutral NaF topical fluoride gel or use of a 0.05% neutral NaF fluoride mouthrinse in both normal individuals and patients with radiation-induced xerostomia. As expected, the gel resulted in higher peak fluoride values than the rinse and was retained in the mouth for longer periods of time in both groups. The xerostomic group expressed a mean oral fluoride concentration of 575 μg fluoride per gram of saliva within 1 min after the gel application and 150 μg/g following use of the mouthrinse, whereas the normal group exhibited peak concentrations of 112 and 71 μg/g, respectively, within 1 min after the same two treatments. The initial high levels of fluoride observed in normal subjects following the gel application decreased rapidly to less than 1 μg/g within 2 h, whereas fluoride levels in the xerostomic subjects remained elevated above 12 μg/g for longer than 2 h. Similarly, following use of the mouthrinse, normal subjects’ saliva fluoride levels decreased to less than 1 μg/g within 1 h, whereas xerostomic subjects’ saliva fluoride levels remained above 4 μg/g for longe

ISSN:0008-6568    

DOI:10.1159/000261126

出版商:S. Karger AG    

年代:1988

数据来源: Karger