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Biomedical subjects

Y Haikel

Publications and source records attributed to Y Haikel.

27 records · Page 2Linked to original sources
PubMed1988

[Evaluation of the Caridex system and its pulp biocompatibility].

A study of the pulpal biocompatibility of the Caridex system was carried out on human premolars to be extracted bilaterally for orthodontic reasons, in 3 volunteers aged 10 to 13 years. A class V cavity was prepared bilaterally on the 2 premolars to be extracted: one of the cavities was washed with Caridex. The other was used as a control. The extractions were made immediately, 4 and 7 weeks after these operative procedures. Histological examinations showed that the Caridex system was biocompatible for the human dental pulp. A comparative study of carious cavities was conducted using light microscopy, Gram stain and transmission electron microscopy on the quality of the cleaning obtained after conventional cavity preparation and use of the Caridex system. After Caridex treatment, the dentinal surface was free of demineralized zones and no smear layer was present. The occasional presence of bacteria was noticed after conventional use of a bur as well as after Caridex. More limited clinical indications of the Caridex system are proposed.

Adolescent↗
PubMed1986

Fluoride content of water, dust, soils and cereals in the endemic dental fluorosis area of Khouribga (Morocco).

The fluoride contents of drinking water, dust, soil, straw, raw barley (ears and stems) and barley grains in Khouribga were compared with those from Beni-Mellal, 90 km east of Khouribga where no fluorosis occurs. Identical fluoride levels were found in water samples from both areas, whereas high amounts of F- were in soil, dust, dried straw and dried barley grown in Khouribga. Equilibrated with water, large phosphate rock particles, probably of francolite, and smaller phosphate particles of clay-contaminated francolite, randomly collected in the factories of Khouribga never contained more than 1.2 parts/10(6) F-. Unwashed samples of straw and whole barley had a higher F- content than washed samples. The marked fluorosis in herbivores of the Khouribga area comes more from the ingestion of dust-contaminated food (unwashed straw and unwashed raw barley) with a high fluoride content than from inhalation of fluoride-containing dust. By contrast, the endemic human fluorosis in the same region is mostly due to inhalation of fluoride-containing phosphate dust, and not to fluoride in the drinking water and only exceptionally to fluoride deposited during storage onto cereals, because grains grown in Khouribga have a low fluoride content.

Dust↗
PubMed1982

[Scanning electron microscopy of the normal and carious aprismatic enamel surface of human temporary teeth].

The study of human primary teeth surfaces by scanning electron microscopy has shown that the localization and the extent of the aprismatic surface layer although present in all teeth studied was quite variable from one tooth to an other. Such an aprismatic layer could be found along the molar fissures. However each tooth studied possessed an important surface layer consisting of prismatic enamel. The respective distribution of prismatic and aprismatic enamel layers was highly variable and can hardly by systematized. The study of apparently intact layers of incipient carious white spot lesions has shown that the irregular type of surface destruction was related to the presence of an aprismatic enamel surface layer.

Child↗
PubMedDate not supplied

Secondary structure of proteins adsorbed onto or embedded in polyelectrolyte multilayers.

The structural changes of bovine serum albumin (BSA) and hen egg white lysozyme (HEL) upon their adsorption onto the surface or their embedding into the interior of poly(allylamine hydrochloride)-(poly(styrenesulfonate) (PAH-PSS) multilayer architectures were investigated by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The presence of the polyelectrolytes seems, as previously observed for fibrinogen (J. Phys. Chem. B 2001, 105, 11906-11916), to prevent intermolecular interactions and, thus, protein aggregation at ambient temperature. The secondary structure of the proteins was somewhat altered upon adsorption onto the polyelectrolyte multilayers. The structural changes were larger when the charges of the multilayer outer layer and the protein were opposing. The adsorption of further polyelectrolyte layers onto protein-terminated architectures (i.e., embedding the proteins into a polyelectrolyte multilayer) did not cause considerable further changes in their secondary structures. The capacity of the polyelectrolyte architectures to delay the formation of intermolecular beta-sheets upon increasing temperatures was not uniform for the studied proteins. PSS in contact with HEL could largely prevent the heat-induced aggregation of HEL. In contrast, PAH had hardly any effect on the aggregation of BSA. The differences are explained on the basis of protein-polyelectrolyte interactions, affected mostly by the nature and the strength of the ionic interactions between the polyelectrolyte-protein contact surfaces.

Adsorption↗
PubMedDate not supplied

Dental caries and fluorosis in children from high and low fluoride areas of Morocco.

The purpose of this study was to estimate the prevalence and the severity of dental caries and dental fluorosis in primary and permanent teeth of 582 subjects, aged 7 to 16 years, from the fluorosis area of Khouribga and the non-fluorosis area of Beni Mellal, Morocco. At age-group 7-10, where 67.8 percent of primary teeth were present, about 35 percent of the children were affected in the high-fluoride area and the community fluorosis index was 0.86. The percentage and average number of erupted permanent teeth were higher in Beni Mellal than in Khouribga for 11-12 and 13-14-year-old age-groups. Significant differences in caries prevalence were observed between the high- and low-fluoride areas. In both regions, high and low prevalence of dental caries was observed in the primary and permanent teeth, respectively.

Adolescent↗