Effect of two X-ray tube voltages on detection of approximal caries in digital radiographs. An in vitro study

Image Quality, Radiation Dose, and Patient Comfort Associated with Wireless Sensors in Digital Radiography: A Systematic Review

Radiography facilities face challenges with the positioning of digital radiography detectors. This study evaluates the image quality, radiation dose, and patient comfort associated with wireless sensors in digital radiography. A systematic exploration was performed across PubMed/MEDLINE, EMBASE, SCOPUS, Web of Science, and SCIELO. Nine papers met the eligibility criteria, including three observational studies with 111 patients, four in vitro experiments with 258 extracted human teeth, and two ex vivo investigations with 16 cadaver mandibles. All studies consistently reported high-quality images produced by wireless sensors. Two studies demonstrated the superiority of wireless sensors, one found comparable accuracy with conventional radiography, and another indicated similar image quality among the sensors. Both wireless and wired sensors significantly reduced radiation doses compared to conventional X-rays. The Visual Analog Scale (VAS) did not reveal a clear superiority of wireless over wired sensors, though both were generally less comfortable than traditional film. The wireless sensors consistently produce high-quality images, comparable to or superior to other digital devices. Both wireless and wired sensors significantly reduce radiation doses compared to conventional X-rays, emphasizing their safety and efficacy. Patient comfort levels vary, with neither sensor type showing clear superiority over the other, and both being less comfortable than traditional film.

Comparison of the performance of intraoral X-ray sensors using objective image quality assessment

OBJECTIVES

The main aim of this study was to evaluate the performance of 10 individual sensors of the same make, using objective measures of key image quality parameters. A further aim was to compare 8 brands of sensors.

STUDY DESIGN

Ten new sensors of 8 different models from 6 manufacturers (i.e., 80 sensors) were included in the study. All sensors were exposed in a standardized way using an X-ray tube voltage of 60 kVp and different exposure times. Sensor response, noise, low-contrast resolution, spatial resolution and uniformity were measured.

RESULTS

Individual differences between sensors of the same brand were surprisingly large in some cases. There were clear differences in the characteristics of the different brands of sensors. The largest variations were found for individual sensor response for some of the brands studied. Also, noise level and low contrast resolution showed large variations between brands.

CONCLUSIONS

Sensors, even of the same brand, vary significantly in their quality. It is thus valuable to establish action levels for the acceptance of newly delivered sensors and to use objective image quality control for commissioning purposes and periodic checks to ensure high performance of individual digital sensors.

Image optimization in digital dental radiography

Presented is a method for establishing the appropriate balance of image quality and radiation dose for dental imaging. Using the Monte Carlo N-Particle Extended (MCNPX) radiation transport code, the DC Planmeca radiographic unit and a dental bitewing phantom were modeled. The Carestream 6100 RVG sensor signal response, noise response, dose rate dependence, and reproducibility were determined experimentally, including uncertainties and inter/intraunit variabilities. The computationally varied parameters were peak kilovoltage and tube filtration. The entrance air kerma for the current clinical technique was used to establish reference image quality. Four figures of merit (FOM) were chosen to encompass parameter variation. With equal weighting of FOMs and no equipment limitations, the optimal parameters were 90 kVp with 0.1 mm added copper filtration. The optimal technique in the radiographic units' operating range was 70 kVp and 0.1 mm added copper filtration, resulting in a ∼50% (±17%) entrance dose and ∼40% effective dose savings.

The Effects on Absorbed Dose Distribution in Intraoral X-ray Imaging When Using Tube Voltages of 60 and 70 kV for Bitewing Imaging

Objectives

Efforts are made in radiographic examinations to obtain the best image quality with the lowest possible absorbed dose to the patient. In dental radiography, the absorbed dose to patients is very low, but exposures are relatively frequent. It has been suggested that frequent low-dose exposures can pose a risk for development of future cancer. It has previously been reported that there was no significant difference in the diagnostic accuracy of approximal carious lesions in radiographs obtained using tube voltages of 60 and 70 kV. The aim of this study was, therefore, to evaluate the patient dose resulting from exposures at these tube voltages to obtain intraoral bitewing radiographs.

Material and Methods

The absorbed dose distributions resulting from two bitewing exposures were measured at tube voltages of 60 and 70 kV using Gafchromic^® film and an anatomical head phantom. The dose was measured in the occlusal plane, and ± 50 mm cranially and caudally to evaluate the amount of scattered radiation. The same entrance dose to the phantom was used. The absorbed dose was expressed as the ratio of the maximal doses, the mean doses and the integral doses at tube voltages of 70 and 60 kV.

Results

The patient receives approximately 40 - 50% higher (mean and integral) absorbed dose when a tube voltage of 70 kV is used.

Conclusions

The results of this study clearly indicate that 60 kV should be used for dental intraoral radiographic examinations for approximal caries detection.

Validity of wax and acrylic as soft-tissue simulation materials used in in vitro radiographic studies

OBJECTIVE

To determine the thickness of wax and acrylic that provides a radiographic density similar to that of the human cheek.

METHODS

An intraoral film radiograph of the human cheek including a 40×30×3 mm reference aluminium block was recorded under standardized conditions in 61 subjects. Radiographic density was measured by a densitometer in ten randomly selected sites of the film to serve as the gold standard for density values of the cheek soft tissues. Thereafter, the density of series of radiographs of two tissue-simulating materials-wax and acrylic-in systematically increasing thicknesses (wax, 1.5-30 mm; acrylic, 2-40 mm) plus the reference block were measured and compared with the gold-standard values.

RESULTS

The radiographic density of wax with a thickness of 13-17 mm or acrylic with a thickness of 14.5 mm corresponded to the average density of the human cheek.

CONCLUSION

The soft tissues of the average human cheek can be simulated with 13-17 mm wax or 14.5 mm acrylic in in vitro radiographic studies.

Effect of tube potential and image receptor on the detection of natural proximal caries in primary teeth

The aim of this study was to assess the detection of proximal caries in primary teeth at three different tube potentials using Ektaspeed films, storage phosphor plates (SPPs), and a charge-coupled device (CCD). Fifty-three extracted human primary molars with natural proximal caries were radiographed with three different imaging modalities--Digora Optime SPP system, RVGui CCD system, and Ektaspeed films--at 50-, 65-, and 70-kV tube potentials. Three observers scored the resultant images for the presence or absence of caries. The definitive diagnosis was determined by stereomicroscopic assessment. The diagnostic accuracy for each imaging modality was expressed as the area under the receiver operating characteristic curves (A(z)). Differences among the A(z) values were assessed using two-way ANOVA and t tests. Kappa was used to measure inter- and intra-observer agreement. Higher accuracy was found for SPPs compared to film and CCD images at all tube potentials. Accuracy was significantly different only at 50-kV tube setting in favor of SPPs (p < 0.05). Inter- and intra-observer agreement was high for all systems. A SPP system can be recommended for dental peadodontic clinics particularly with 50-kV tube potential for the diagnosis of proximal caries since further advantages include the elimination of chemical processing, image enhancement, and a better low-contrast detectability performance.