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Objectives: To compare the diagnostic accuracy of conventional film, unenhanced direct digital and inversion grayscale direct digital imaging in the detection of approximal caries., Methods: 150 approximal surfaces of extracted permanent molars and premolars were selected for the study on the basis of varying lesion depth. The teeth were radiographed using Ektaspeed Plus film; digital images were made with a Schick CMOS-APS sensor. 7 examiners evaluated 58 randomized images of each modality. Histological sectioning of the teeth was used to verify the presence and extent of decay., Results: No significant difference was found between the diagnostic accuracies of the three imaging modalities (P=0.226). Analysis of the diagnostic accuracy of the three modalities on lesion depth showed no statistically significant interaction; however, the main effect of the lesion depth was significant (P<0.001, eta(2)=0.936)., Conclusions: The overall diagnostic accuracy of the three modalities in the detection of approximal carious lesions was comparable. All three modalities performed poorly in the detection of enamel lesions.

Using projection geometry, algebraic formulas, and different beam indicating devices (BIDs), the surface area and volume of tissue exposed for a hypothetical patient was determined. Combinations of 4 BID lengths and shapes were used: 4-inch (10.2 cm.) pointed plastic, 8-inch (20.3 cm.) round plastic, 14-inch (35.6 cm.) round aluminum, and 14-inch (35.6 cm.) rectangular aluminum. As each subject BID was progressively lengthened and collimated, the area and volume of tissue exposed was reduced. The calculated area and volume of exposed tissue for the 14-inch rectangular aluminum open-ended lead-lined BID was 16.6 cm.2 and 327.7 cm.3, respectively. This represented 9% of the area and 8% of the volume of tissue exposed using the 4-inch round pointed plastic BID or a 91% (area) and 92% (volume) reduction in patient exposure.

Objective: The aim of this study was to compare panoramic temporomandibular joint radiography, unenhanced and color-enhanced digital-subtraction radiography with respect to detectability of simulated osteophytic lesions of the mandibular condyle., Methods: Three dry human skulls with no obvious temporomandibular joint pathology were selected. Four sizes of bone chips were placed on the anterior aspect of the condyle at medial, central, and lateral locations. Panoramic radiographs were made with and without the chips in place. These paired radiographs were digitized, and unenhanced and color-enhanced digital-subtraction images of the original panoramic images were obtained. Eight observers evaluated 72 randomized images of each modality for the presence or absence of simulated osteophytic lesions of the mandibular condyle, grading the images on a 100-point scale., Results: A(z) values for overall diagnostic accuracy of the three imaging modalities were 0.5376 for panoramic radiography, 0.7861 for unenhanced digital subtraction radiography, and 0.7923 for color-enhanced digital-subtraction radiography. Digital-subtraction radiography improved the detection accuracy of the original panoramic films., Conclusion: Panoramic radiographs were significantly less accurate in the detection of simulated osteophytic lesions of the mandibular condyle than the two digital-subtraction techniques.

Our purpose was to develop educational software that would simulate laboratory investigation of problems in Rh immune globulin prophylaxis and hemolytic disease of the newborn. An interactive, branching style program was developed using a 256K Penonal Computer (International Business Machines, Boca Raton, FL). The software has been used in over 125 institutions for preprofessional and continuing professional education.

A study was undertaken to determine whether the prevalence of hepatitis B surface antibody (anti-HBs) increased among students in a dental school after exposure to patients. Predoctoral students were followed during their 4 years of dental school. An anti-HBs determination was made before patient contact and again just before graduation. Of the 247 predoctoral students initially tested, 6.1% were found to be anti-HBs positive. Of these only 145 students were tested again before graduation; four (2.8%0 who were initially anti-HBs negative seroconverted during the testing period. In addition, 31 staff, 73 graduate students and faculty, and 21 dental hygiene students were also tested for anti-HBs seroprevalence. This single test revealed 6.5% of the staff, 8.2% of the graduate students and faculty, and 4.8% of the hygienists to have the positive marker.

This article summarizes the use of rare earth screen technology to achieve high-quality panoramic and cephalometric radiographs with sizable reductions in patient radiation dosage. Collimation, shielding, quality control, and darkroom procedures are reviewed to further reduce patient risk and improve image quality.

Contamination of processor solutions adversely affects the image quality of radiographic films. The purpose of this study was to determine the amount of developer or fixer contaminant that was necessary to produce a significant densitometric change in the base plus fog, speed, or contrast optical density readings for panoramic film. Significant differences in base plus fog (after 16 mL of fixer contaminant was added to developer), speed index (after 4 mL), and contrast index (after 8 mL) were observed in comparison with control values.

A double blind study was conducted utilizing the EDL/Biometrics Reading Eye Camera to determine if poor diets and altered reactions could have a detrimental effect on the eye movements of a group of dyslexic individuals. The study found that a poor diet, high in sugar, and a provocative challenge of cane sugar caused more erratic eye movements, while a good diet, without sugar, caused "normal" eye movements for the dyslexic individuals.

The purpose of this study was to develop educational software to simulate laboratory investigation of transfusion reactions. An interactive, branching-style program was developed using a 256K Personal Computer (International Business Machines, Boca Raton, FL). Over 75 institutions in the United States and Canada are currently using the software in preprofessional and continuing professional education programs.

The purpose of this study was to determine and to compare the titers of salivary anti-A and anti-B antibodies in two groups of patients with periodontal disease as measured by Russell's Periodontal Index (PI). Forty volunteer subjects, who were new patients assigned to a screening clinic, were selected for the study based on the following criteria: (1) blood group, (2) medical history, (3) age and (4) periodontal condition. One group of patients (N = 20) had a PI of less than 2.0 and the other group of patients (N = 20) had a PI of greater than 4.0. Following screening, a 10-ml sample of unstimulated whole saliva was collected, centrifuged and frozen. Within 30 days the saliva was thawed, titrated and tested for presence of anti-A and anti-B. Saliva agglutinin titers were determined using a variation of previous testing techniques. Statistically significant differences between the two groups were not obtained in the titers of salivary anti-A (U = 192.5; P greater than 0.1) or the titers of salivary anti-B (U = 162.8; P greater than 0.1). All 40 group O patients were found to have anti-A and anti-B in their saliva.