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Biomedical subjects

A C Shearer

Publications and source records attributed to A C Shearer.

9 recordsLinked to original sources
PubMed1991

Quantitative assessment of a new dental imaging system.

The "Radiovisiography" dental imaging unit (Trophy UK Ltd) is a digital system using an intensifying screen and charge-coupled device in an intra-oral sensor. This paper presents a description of the system and an assessment of the original model in terms of patient dose (relative to film systems), resolution (limiting resolution and modulation transfer function), distortion and image noise (amplitude). The system does offer the possibility of reduced patient exposure and minimal distortion, although resolution and latitude are inferior to standard dental film.

Humans↗
PubMed1991

Radiovisiography for length estimation in root canal treatment: an in-vitro comparison with conventional radiography.

Radiovisiography (RVG) and conventional film (CF) were compared in an in-vitro study for working length estimation of root canals. Hedstrom files (size 15) were placed in the root canals of 60 extracted teeth and the teeth imaged using both CF and RVG. The length of file observed was assessed on CF, RVG and enhanced RVG images. The results indicated that a greater length of file was imaged with CF than with RVG (P less than 0.05). However, enhanced RVG images were not significantly different from CF images. While clinical studies are now indicated to confirm these results, it is suggested that, when utilizing RVG for length estimation in root canal treatment, the enhancement facility should be used.

Dental Pulp Cavity↗
PubMed1990

Radiovisiography: an initial evaluation.

An initial evaluation of the latest dental radiographic imaging system, radiovisiography, is reported. Despite limitations in its possible clinical applications and problems inherent within the system design, radiovisiography has been found to be a rapid imaging system capable of producing clinically acceptable periapical images. It is suggested that this system may be of particular value in endodontics and in its present form should be considered as an adjunct rather than as a replacement for conventional intra-oral film. Further studies are now required into recent system modifications which are described.

Adolescent↗
PubMed1990

Radiovisiography for imaging root canals: an in vitro comparison with conventional radiography.

Radiovisiography is a rapid, low-dose, digital imaging system that utilizes a small, intraoral sensor in place of radiographic film. Because of these characteristics, it may be particularly suitable for use in endodontics. Consequently radiovisiography and conventional film radiography for the imaging of root canals were compared in vitro. There was no statistically significant difference between the percentage of length of root canal visible on conventional film and that visible on radiovisiographic images. Thus, radiovisiography may be considered to be of equal value to conventional film radiography for the imaging of root canal systems in vitro.

Dental Pulp Cavity↗
PubMed1989

Image analysis of radiolucencies in approximal enamel: a comparison of xeroradiographic and conventional film images.

Xeroradiographic and conventional film bitewing images of radiolucencies in approximal enamel were compared using a computer-aided image analysis system. Densitometric analysis of the conventional film types used in the study showed that the "lead foil free" film exhibited lower overall density when compared with conventional D-speed film. Computer-aided image analysis of radiolucencies in approximal enamel found that xeroradiographs depicted a higher degree of demineralization and a larger area than conventional radiography with the "lead foil free" film.

Adolescent↗
PubMedDate not supplied

Radiography for the diagnosis of dental caries in posterior teeth.

The role of radiography in the detection and monitoring of dental caries in posterior teeth is reviewed. Variables in radiographic technique, including the use of different image projections and receptors, are considered. The contribution of radiography to the diagnosis of approximal, occlusal, and recurrent caries is reviewed, as is the use of radiography for the monitoring of caries progression.

Bicuspid↗