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Biomedical subjects

W M Amin

Publications and source records attributed to W M Amin.

10 recordsLinked to original sources
PubMed2001

Oral health status of workers exposed to acid fumes in phosphate and battery industries in Jordan.

OBJECTIVES: To investigate the prevalence and nature of oral health problems among workers exposed to acid fumes in two industries in Jordan. SETTING: Jordan's Phosphate Mining Company and a main private battery factory. DESIGN: Comparison of general and oral health conditions between workers exposed to acid fumes and control group from the same workplace. SUBJECTS AND METHODS: The sample consisted of 68 subjects from the phosphate industry (37 acid workers and 31 controls) drawn as a sample of convenience and 39 subjects from a battery factory (24 acid workers and 15 controls). Structured questionnaires on medical and dental histories were completed by interview. Clinical examinations were carried out to assess dental erosion, oral hygiene, and gingival health using the appropriate indices. Data were statistically analysed using Wilcoxon rank-sum test to assess the significance of differences between results attained by acid workers and control groups for the investigated parameters. RESULTS: Differences in the erosion scores between acid workers in both industries and their controls were highly significant (P<0.05). In both industries, acid workers showed significantly higher oral hygiene scores, obtained by adding the debris and calculus scores, and gingival index scores than their controls (P<0.05). The single most common complaint was tooth hypersensitivity (80%) followed by dry mouth (77%) on average. CONCLUSION: Exposure to acid fumes in the work place was significantly associated with dental erosion and deteriorated oral health status. Such exposure was also detrimental to general health. Findings pointed to the need of establishing appropriate educational, preventive and treatment measures coupled with efficient surveillance and environmental monitoring for detection of acid fumes in the workplace atmosphere.

Acids↗
PubMed2001

Fluoride release from glass ionomer restorative materials and the effects of surface coating.

OBJECTIVES: This in vitro study on fluoride (F) release from conventional and metal-reinforced glass ionomer investigated the following: (1) the release of F in deionized water compared to artificial saliva, (2) the effect of various surface coatings on F release, (3) the uptake of released F by hydroxyapatite, (4) the expression of the release data in a mathematical model, (5) F content in the powders and set materials, and (6) surface morphology of varnished and resin-coated specimens. METHODS: Glass ionomer Ketac-Fil (KF), Fuji II (FJ), and Ketac-Silver (KS) were mixed according to the manufacturers' instructions, and prepared into specimens of 137.8 mm2 surface area. All three specimens were suspended in 50 ml of deionized water, artificial saliva, or aqueous solution of hydroxyapatite and submitted to constant agitation at 37 degrees C. In a separate experiment, the specimens were coated with varnish or light-cured bonding resin and tested for F release in solutions similar to those for uncoated specimens. The release of F occurred for 28 days. The concentration of F was measured with F-ion-specific electrode. RESULTS: All tested products showed a strong initial rate of F release which decreased with time until it reached a relatively steady rate after two weeks. The F released from KF and FJ was comparable in both pattern and magnitude. They released approximately four times more F than KS. In all cases, the release of F in artificial saliva was significantly (p < 0.001) less than in deionized water. Surface coating the specimens significantly reduced the F release ( p < 0.05 top < 0.001, depending on the product and type of coating). The inhibitory effect of coating markedly decreased with time. Resin coating reduced F release more than varnish in KF and KS, but not for FJ. Essentially, all F released in aqueous solution was taken up by the hydroxyapatite, with FJ ranking the highest in increasing hydroxyapatite F concentration. Over the 28 days, the quantities of F released from FJ, KF, and KS were, respectively, 3.8, 2.3, and 1.0% of the total F content in the specimens. The F concentration in the set KS was 53.9 and 72.5% of that found in KF and FJ, respectively. The release data as a function of time were best described by the power curve. Micromorphological examinations revealed remnants of surface coatings on specimens after 14 days storage in artificial saliva. CONCLUSIONS: Glass ionomer cements released significantly less F in artificial saliva than in deionized water. Surface coating the specimens substantially reduced F release. These clinically relevant factors were not considered by many in vitro release studies which overestimate the F availability from glass ionomers. A recall appointment 24 h after the placement of glass ionomer restoration should be given for surface finishing.

Cermet Cements↗
PubMed1983

The level of residual monomer in self-curing denture-base materials.

Because residual monomer may cause tissue irritation, we investigated two self-curing acrylic denture-base materials--one a compression type, and the other a pourable material--by means of gas-liquid chromatography. Both exhibited higher residual monomer levels than did heat-cured acrylics, with thick sections having lower values than did thin sections. The pourable material showed lower values than did the compression variety.

Acrylic Resins↗
PubMed1982

Colour stability of two self curing denture base materials.

It is important that denture base materials should be colour stable, yet some self curing materials do not fulfill this requirement. Two newly introduced materials, one a 'pour type' resin, were investigated using a sophisticated colorimetric instrument to assess colour changes that might result from contact with water and denture cleansers. Both materials showed measurable colour changes following a two week soaking period, but these were barely perceptible to the eye. The possible reasons for colour instability are discussed.

Acrylic Resins↗
PubMed1982

Compatibility of denture cleansers with some new self curing denture base materials.

All denture base materials are subjected to abrasion during function, but this will be greatest under certain denture cleansing regimens. Two new materials, a 'pour type' and a compression moulding acrylic resin were subjected to mechanical brushing with denture cleansers. It was found that abrasion resistance of the two materials was of the same order, and weight loss was greatest with one of the paste cleansers.

Acrylic Resins↗