Barton M. Gratt

Variations in the radiographic interpretation of the periapical dental region

Radiographic interpretation of the periapical region is considered to be inconsistent, with a wide variation between observers. Toward improving the interpretation of this important region, the influence of 18 radiographic features on the consistency and reliability of interpretation of this are was investigated. Fifty-six radiographs of healthy and pulp diseased (vital and nonvital pulps) teeth were interpreted by 10 dentists. Results indicated that the pattern, size, and density of bone trabeculae are the best radiographic features for identifying “healthy” teeth. The lamina duras continuity and shape and the periodontal ligaments width and shape were the most consistent features for diagnosis of teenth with nonvital pulps. Radiographic interruptions in the continuity of the lamina dura were detected by all observers; nevertheless, this important finding was not strongly considered in the overall interpretation assessment. Variations in interpretation were found among observers; however, these variations were decreased by using mean observers opinions for interpretation. In addition, interpreting independently the lamina dura continuity, shape and density, and the periodontal ligament width and shape proved to be the best radiographic features reducing interobserver variations and provided the dentist with a more constant and correct diagnosis.

Xeroradiography of dental structures. I. Preliminary investigations.

Xeroradiography has several inherent technical advantages over intraoral film radiography, as well as many convenience features. We found that a conventional dental x-ray unit can act as an excellent source of radiation for xeroradiography of dental structures. Furthermore, high-quality images of soft tissue, bone, and teeth were produced at radiation exposures up to seven times less than for conventional intraoral film radiography. This demonstration of reduced radiation exposure should further encourage research into the applicability of xeroradiography to the imaging of dental structures.

Xeroradiography for intraoral dental radiology: A process description

A novel x-ray imaging system for intraoral dental radiography is described. The imaging process is based on xeroradiographic principles. The surface of a small selenium photoreceptor is electrically charged. After insertion into a light-tight cassette, the photoreceptor is placed intraorally and x-ray exposed like film. The resultant electrostatic charge image is developed in a processor using liquid toner. The toner image is then transferred from the photoreceptor and fixed to a white plastic substrate for viewing. After cleaning, the photoreceptor is available for reuse. In contrast to film images, xeroradiographic images are exposed and processed sequentially. Processing time is approximately 20 seconds. Two image characteristics--edge enhancement and deletion--are primarily responsible for many advantageous qualities of xeroradiographic images over film images. An experimental processor was tested successfully at two dental schools.

Xeroradiography of dental structures: II. Image analysis☆

Xeroradiography provides an attractive, convenient, low-radiation-dose alternative to conventional intraoral film radiography. In this study the image properties of the two techniques were compared quantitatively and qualitatively. Over all, image quality was very similar, but xeroradiography delivered radiation doses seven to fourteen times less than conventional film radiography.

Observer variations in the interpretation of periapical osseous structures: A comparison between xeroradiography and conventional radiography

This study was designed to examine observer variations and reproducibility in the interpretation of the periapical bony region using conventional film radiography and xeroradiography. Six dentists (two endodontists, two general dental practitioners, and two oral radiologists) evaluated the periapical bony region of 75 roots using six categories ranging from definitely normal to definitely bone destruction. Large observer variations existed with both film and xeroradiography, but no differences in interobserver variations or intraobserver reproducibility were found between the radiographic methods. However, interpretive differences were found as the dentists used the categories definitely normal or probably normal more often in viewing the xeroradiographs.

Dental xeroradiography for endodontics: a rapid X-ray system that produces high-quality images

Dental xeroradiography produces images of superior quality at approximately a third of the radiation dose of conventional intraoral film radiography. A prototype xeroradiographic system for intraoral use was evaluated for use in endodontic treatment by comparing similar X-ray projections of dental xeroradiographs and conventional film images among patients undergoing endodontic therapy. The xeroradiographs were judged superior for detecting periodontal ligament spaces, root apexes, details of the root canal system, pulp stones, metal instruments, and root canal filling materials. Furthermore, xeroradiographic image processing is both convenient and rapid as it requires only 20 seconds for the production of a dry, permanent image. Dental xeroradiography may aid in the practice of endodontics.

Xeroradiography of dental structures. III. Pilot clinical studies.

A new experimental intraoral dental xeroradiographic system was evaluated for future application in dentistry. Similar projections on conventional film radiographs and experimental dental xeroradiographs were compared visually and radiation exposure for both techniques was measured by thermoluminescent dosimetry. The xeroradiographic system was judged superior for imaging most structures, especially oral soft tissues, subtle bony abnormalities, and fine calculus deposits. Furthermore, xeroradiography requires only one third the radiation exposure of corresponding conventional film techniques. Dental xeroradiography appears to have great promise in radiographic interpretation of oral disease.

A clinical comparison of xeroradiography and conventional film for the interpretation of periapical structures

Xeroradiography and D-speed and E-speed film radiography were evaluated for the radiographic interpretation of periapical disease. Fifty-six consenting dental patients, either with or without periapical disease, were studied. Each patient received two radiographic examinations, one using xeroradiography and the other using either D-speed or E-speed film. Each tooth in the study population was evaluated independently relative to its history, clinical appearance, and clinical test results. Diseased teeth were endodontically treated. Teeth judged to be normal were followed for 1.5 yr to verify a clinically asymptomatic state. In both cases clinical assessments determined the true presence or absence of disease. Ten dentists scored the radiographic images for the presence of periapical disease and changes of various anatomical structures. Receiver-operating-characteristic (ROC) analysis of the three imaging techniques demonstrated no statistical difference in the diagnostic utility of xeroradiography (0.842 receiver-operating characteristic value) versus conventional radiography (0.843 receiver-operating characteristic value). In terms of radiation dose, xeroradiographic and E-speed film images required about one half the patient radiation exposure of D-speed film radiography. Therefore, xeroradiography or E-speed film techniques are preferred over conventional D-speed film radiography for the interpretation of periapical structures.

Leaded shields for thyroid dose reduction in intraoral dental radiography

This study evaluated the radiation dose reduction, operator acceptance, and patient acceptance of two types of leaded thyroid shields designed for use during intraoral dental radiography. Exposure levels were measured with thermoluminescent dosimeters on three groups of 20 patients undergoing complete mouth (20-film) surveys. Skin entrance dose to the thyroid was 20 mR per complete mouth survey without a shield in place, 12 mR per complete mouth survey with the experimental shield in place, and 9 mR with the commercial shield. Patients and radiologic technologist were surveyed to determine patient comfort and operator acceptability. Patient and operator acceptability were higher for the experimental shield than for the commercial shield.

Xeroradiography for imaging biomaterials--A comparison with conventional radiography.

Our visual comparison of dental xeroradiographs versus conventional film radiographs demonstrated the superiority of the dental xeroradiographic technique for the imaging of all radiolucent and mild-to-moderately radiopaque materials. Both systems were equally valuable for the imaging of very dense radiographic materials such as gold and amalgam alloys.