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Biomedical subjects

J Arends

Publications and source records attributed to J Arends.

At least 163 records · Page 9Linked to original sources
PubMed1987

Surface-free energy and bacterial adhesion. An in vivo study in beagle dogs.

Conflicting reports have been presented on the rôle of substratum surface free energy (s.f.e.) on bacterial adherence. It is the aim of the present study to evaluate the effect of the s.f.e. of substrata on bacterial adherence in vivo. The following substrata with s.f.e. varying from 23.3-124.9 erg X cm-2 were cut into facings of 5 by 6 mm, polished and cleaned: polytetrafluorethylene (PTFE), Parafilm, polyvinylchloride (PVC), polymethylmethacrylate (PMMA), bovine dentin, bovine enamel and glass. In 5 beagle dogs, 7-9 years old, part of the buccal periodontium of the upper cuspids was excised and crowns were made and cemented with a non-fluoridated cement. The facings were placed in the crowns and placed in the oral cavity for 2 h. After removal, the facings were rinsed in saline. S.f.e. was assessed from contact angles with water, water/n-propanol mixtures and a-bromonaphthalene, according to the concept of dispersion and polar components, firstly on clean air dried facings and later on facings exposed to the oral cavity for 2 h. Immediately after rinsing, the water contact angle was measured as a function of time, to monitor the evaporation of free water from the protein layer adsorbed on the substrate which had been exposed to the oral cavity. It appeared that after a rapid increase in contact angle, a stable maximum value was obtained after 40-120 min depending on the substratum. S.f.e.'s of the protein-coated substrata were subsequently determined after a 120 min drying period. Following the contact angle determinations, the exposed facings were stained with ethidium bromide, enabling fluorescence microscopical counting of the adhered microorganisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

SEM and microradiographic investigation of initial enamel caries.

In this paper a combined microradiography and SEM study is presented on human enamel after a caries attack in vivo for a 4-wk period. The initial enamel caries is induced under a specially designed orthodontic band; plaque accumulation takes place under a niche in the band. The microradiography and SEM were done on the same sections. A special manipulation and breaking technique of the thin sections makes it possible to observe with the SEM, demineralized enamel areas with a mineral content known from microradiography. The results show that with a mineral content of about 50 vol. %, the observable porosity is noticeable at the prism level (interprismatically) but barely noticeable at the cyrstallite level. The surface morphology of the demineralized enamel is at low magnifications not very different from sound enamel. At high magnifications, however, the surface porosity becomes visible. The results indicate that the mineral in vivo losses in enamel after an initial caries attack can be explained mainly by mineral losses from interprismatic areas and from the prism peripheries.

Adolescent↗
PubMed1987

Fluoride varnishes--a review.

Fluoride varnishes were developed as alternatives to the conventional topical applications, mainly to prolong contact time between fluoride and teeth. Two marketed products, Duraphat and Fluor Protector, have been extensively tested and are generally accepted for clinical use. In this overview of fluoride varnishes the state of the art of both products is presented. Fluoride uptake, demineralization inhibition and caries prevention induced by varnish applications are discussed. In general it is concluded that varnishes are toxicologically safe, easy to use, and possess excellent cariostatic properties. When re-applied regularly, twice a year, and combined with normal oral hygiene procedures they are topical fluoride agents with very good caries preventive properties.

Dental Caries↗
PubMed1987

Surface roughening of human enamel after toothbrushing.

Grooves and scratches on the enamel surface are potential and preferential sites for bacterial adhesion. During toothbrushing groove formation is a potential risk especially in dentin. To obtain information on groove formation in enamel a profilometric experiment has been carried out on polished human enamel. The main result is that no groove formation with a depth more than a few tenths of a micrometer is observable even after 50.000 toothbrush strokes. The fact that material is removed by toothbrushing is indirect proof that enamel is removed by continuous brushing in layers more or less parallel to the original surface.

Adult↗
PubMed1987

Mineral distributions in enamel after in vivo de- and remineralization.

Plates of human enamel were demineralized under plaque in 18 participants. The subjects were randomly allocated to 3 groups consuming 0, 1 or 2 filled chocolate products (FCP) in between meals daily for periods of 4 weeks. Subsequently, the specimens were remineralized in vivo for 9 weeks, with or without the consumption of an FCP. The mineral distribution was assessed by means of microradiography. Special emphasis was placed on the type of mineral distribution. The results showed that: 1) significantly more enamel samples demineralized in vivo with a surface layer covering the lesion, when FCP's were eaten in between meals. The ranking of the number of samples with a surface layer was 0 FCP less than 1 FCP less than 2 FCP. 2) The amount of mineral lost during demineralization was not statistically different between 0 and 1 FCP. There is a difference between 0 and 2 FCP. 3) There was no difference in surface layer thickness or mineral content in the surface layer of 0, 1 or 2 FCP consumption in the demineralization experiment. 4) After 9 weeks a substantial remineralization occurred. There was no difference in remineralization between the 0 and 1 FCP group. 5) No difference in the percentage remineralization was found between mineral distributions with or without a surface layer.

Cacao↗
PubMed1986

Smoothing effect of a new alpha-glucosidase inhibitor BAY m 1099 on blood glucose profiles of sulfonylurea-treated type II diabetic patients.

The alpha-glucosidase inhibitor BAY m 1099, a deoxynojirimycin derivative, was studied in sulfonylurea-treated type II diabetic patients using a placebo-controlled double-blind cross-over design. Given in two daily doses the inhibitor smoothened the blood glucose profile by lowering significantly post-prandial blood glucose peaks. Fasting and daily mean blood glucose levels measured as the area under the blood glucose curves were however not influenced significantly. This might be due to the short duration of the treatment periods or the low dosage of the drug. Abdominal side effects were negligible. The alpha-glucosidase inhibitor BAY m 1099 might become a useful therapeutic tool in addition to sulfonylurea treatment in type II diabetes.

1-Deoxynojirimycin↗