Search PubMed⌕ Search

Biomedical subjects

A G Farman

Publications and source records attributed to A G Farman.

At least 19 recordsLinked to original sources
PubMed1992

Expediting prior approval and containing third-party costs for dental care.

Dental insurance carriers frequently require referral of radiographs for determination of prior approval. Radiographs are also often used for obtaining expert opinions before finalizing diagnoses and establishing treatment plans. Traditionally, such referrals have been carried out using the original or duplicate films transmitted through the postal system. Studies concerning alternative communication media for data transmission are presented, namely, the use of switched-digital telephone lines and of electronic mail networks.

Computer Communication Networks↗
PubMed1992

Infection control for dental radiographic procedures in US dental hygiene programmes.

Infection control in dental radiographic procedures in US dental hygiene programmes has been investigated by means of a questionnaire and 76% (n = 148) responded. For intra-oral radiography, all but two programmes required the use of gloves during exposure procedures and 94% also required them during processing. Glasses, masks and other protective clothing were required less frequently than gloves. Equipment and working surfaces in the radiographic operatory were generally either disinfected or draped. Equipment and working surfaces in the darkroom were not usually afforded the same degree of diligence in disinfection. Most programmes dried film packets before processing and gave no special treatment to films after processing. Waste products were generally either tied off and marked as a biohazard or sterilized.

Dental Hygienists↗
PubMed1992

Communication in digital radiology.

The long-distance transfer of dental radiographs was explored as early as the 1920s. The practicality of such image transfer has improved through advances in telecommunications and computer networks (both hardware and software) and the emerging trends towards direct and indirect digital imaging techniques for recording oral and maxillofacial radiographs. This paper reviews the current status of communication in digital dental radiology. It is illustrated by personal observations from a variety of demonstration projects.

Computer Communication Networks↗
PubMed1991

Effects of gamma radiation on the in vitro wear of composite restorative materials.

The effects of gamma radiation at therapeutic dosage levels on the wear of three anterior (two light-cured and one autocured) composites and a light-cured posterior composite were studied in vitro. Specimens were subjected to successive sets of 100 abrades to a maximum of 500 abrades on a reciprocating arm abrader, with the dimensional change being recorded between the sets of abrades. The data showed that there were no significant effects on the wear rates of any of the materials tested. The rate of height loss was similar for the two hybrid composites tested (P less than 0.05), as was that for the microfilled and conventional material (P less than 0.05). There was, however, a significant difference (P greater than 0.001) in the wear behaviour between the two groups.

Acrylic Resins↗
PubMed1991

Radiation safety and quality assurance in US dental hygiene programmes, 1990.

A 1990 survey of US dental hygiene programmes indicated substantial advances in radiation safety and quality assurance techniques since 1985. None the less, further improvements are possible to minimize operator and patient exposure to ionizing radiation from dental radiography. Conversion to faster receptor speed, the use of rectangular collimation and more frequent performance of quality assurance tests represent possible improvements for some establishments.

Dental Hygienists↗
PubMed1990

The radiographic density of composite restorative resins.

The radiodensities of enamel, dentin, aluminum, and 14 modern composite resins at thicknesses of 1 to 4 mm were compared. Nine of the 14 composites were radiopaque with respect to that of aluminum. Radiolucent lesions or voids were simulated by cutting grooves 0.5, 1.0, and 2.0 mm deep in aluminum stepwedge blocks, superimposing stepwedges of the radiopaque composites over the blocks, and radiographing the combination. It was found that only five of the nine radiopaque composite materials possessed radiodensities that permitted clear radiographic detection of the smaller defects.

Absorptiometry, Photon↗
PubMed1990

Mucous cyst of the sphenoid sinus.

Sphenoid sinus mucous cysts are rare, benign, expansile masses, which can form mucoceles if the entire sinus is filled. Due to their close proximity to numerous important anatomical structures, they can cause a variety of different symptoms. The incidental finding of a sphenoid sinus mucous cyst during cephalometric radiology for orthodontic analysis is reported.

Cephalometry↗
PubMed1989

Evaluation of aluminum-yttrium filtration for intraoral radiography.

In comparison with the use of traditional aluminum filtration, a radiation dose reduction of 40% at 90 kVp and 25% at 70 kVp was found with the use of aluminum-yttrium (Al-Y) filtration for intraoral bitewing and periapical radiographs. An increased exposure time, and consequent greater tube loading, was necessary to maintain film density. Extended gray-scales (i.e., reduced radiographic contrast) occurred at both energy levels tested with the use of Al-Y filtration. Subjective evaluation of image quality in terms of clarity, resolution, and contrast was carried out independently by nine periodontologists. Despite some interoperator variance, there was a preponderant preference for traditional aluminum filtration.

Aluminum↗
PubMed1989

The effects of gamma radiation on the properties of composite restorative resins.

The effects of gamma radiation at therapeutic dosage levels on the physical properties of three anterior (two light-cured and one autocure) composites and a light-cured posterior composite were studied. Gamma radiation had no effect on the autocured composite but had varied effects on the light-cured systems. The diametral tensile strength and dimensional stability were unaffected, water sorption and solubility were reduced but surface and bulk hardnesses were increased with the hardness increases linearly related to the radiation dosage. These effects may arise from continued polymerization of the air-inhibited surface layer and possibility of low molecular weight entities within the matrix. Overall, therapeutic levels of gamma radiation had no detrimental effects on the physical properties of the composite resins.

Adsorption↗
PubMed1988

Diagnostic radiology of maxillary sinus defects.

Simulated radiolucent and radiopaque defects were placed in the maxillary sinus. Periapical dental radiographs could detect radiopacities of 0.25 mm in diameter; however, such defects were not revealed by occlusal radiography or the posterior-anterior view. Panoramic dental radiographs detected simulated radiopaque lesions more frequently than the other techniques tested, but generally distorted the position of the defect and consistently did not reveal radiolucent defects. Computerized tomography proved to be the most accurate technique used in detection of simulated lesions on all the surfaces of the maxillary sinus.

Humans↗