A comparative study of image quality and radiation exposure for dental radiographs produced using a charge-coupled device and a phosphor plate system

Evaluation of Two Dental Digital Imaging Systems Based on Quality Scorings, Burn-Out Effects and Cervical Width Determination

Background/Aim: The aim of the present study is to evaluate diagnostic accuracy of two generic image receptors with CMOS and PSP sensors for image quality scoring (IQS), burnout incidences (BI) and cervical widths (CW) with regard to four different exposure times.

Material and Methods: 43 incisor teeth within 15 paraffin block models were exposed at 4 different exposure times both for the CMOS and PSP groups, and a total number of 120 images were obtained. All images were evaluated by 3 dentomaxillofacial radiologists via 3 different criteria; IQS, BI, CW.

Results: Diagnostic quality scorings between groups displayed statistically significant difference for 0,1; 0,125 and 0,16 sec exposure times. PSP group revealed higher IQS. For 0,125 and 0,16 seconds exposure times, PSP group showed higher percentages of BI. Average CW were lower in PSP group. Although no statistically significant difference was found between average CW vs. exposure times in the CMOS group; PSP group revealed significant differences among exposure times. We can state that, the PSP system displayed higher image quality so exposure times can be reduced, alas, the same conclusion is not possible with CMOS system used.

Conclusions: Image quality perception is higher in PSP system we used, compared with CMOS system. PSP system display more burnout effects with increasing exposure times, while CMOS system is constant.

Comparison of two digital intraoral radiography imaging systems as a function of contrast resolution and exposure time

BACKGROUND

To compare the image quality of two different digital imaging systems; one photostimulable phosphor plate system (PSP) and a direct digital radiography system with CMOS imaging sensor; via evaluating contrast resolution among four different exposure times.

METHODS

Endodontically treated incisor teeth embedded in paraffin blocks are aligned next to a 99.5% Al wedge and exposed for 0.8, 0.1,0.125 and 0.16 seconds using both the CMOS and PSP systems. Using ImageJ software, 5 isometric and isogridded ROI from each root filling area and isometric ROI from the Al stepwedge were calculated.

RESULTS

Evaluation of the total of 120 images displayed that PSP system produced significantly higher contrast resolution (P<0.05) in regard to pixel values than the CMOS. The CMOS system was non- responsive to increasing dose (P=0.000). Regarding the EqAl values, no significant difference was determined between groups (P>0.05).

CONCLUSIONS

The contrast resolution was higher using the PSP system. It can be estimated that, filling material will be more obvious under lower doses using PSP.

Comparison of Efficiency and Image Quality of Photostimulable Phosphor Plate and Charge-Coupled Device Receptors in Dental Radiography

The photostimulable phosphor (PSP) plate and charge-coupled device (CCD) are receptors commonly used for intraoral radiography in U.S. dental schools. However, it is unclear which receptor is more beneficial for radiology education and patient care in an academic setting. The aim of this study was to compare the time efficiency, image quality, and operator performance for student-operated PSP plate and CCD receptors. At one U.S. dental school in 2018, 20 dental hygiene and dental students (n=10 each) were recruited as operators. They each exposed anterior and posterior periapical and bitewing radiographs on dental radiograph teaching and training replica using the PSP plate and CCD as receptors. The time taken to expose the radiographs was recorded. Image sharpness/definition, brightness/contrast, and technical errors, including placement, angulation, and cone cut errors, were evaluated on a three-point scale with 0=non-diagnostic, 1=diagnostic acceptable with minor errors, and 2=perfect diagnostic quality. The results showed that it was generally faster for the students to expose intraoral radiographs with CCDs than with PSP plates, although the difference was not significant (p>0.05). Image quality and technical accuracy, especially angulation, were significantly superior for PSP relative to CCD (p<0.05). This study found that PSP imaging was of higher quality and accuracy than CCD, whereas CCD was more efficient. Dental and dental hygiene students would benefit from being trained on both receptors to be able to adapt to a diversified workplace.

The quality of radiographs accompanying endodontic referrals to a health authority clinic

AIM

To assess the quality of radiographs accompanying endodontic referrals, from general dental practitioners, to a health authority clinic.

METHODS

A total of 200 conventional film and digital radiographs accompanying referrals were assessed and rated as 'excellent', 'diagnostically acceptable' or 'unacceptable' according to the National Radiographic Protection Board (NRPB) guidelines. Statistical analyses of the results included inter- and intra-observer agreement to achieve a kappa score and the chi-squared test.

RESULTS

Out of the 200 radiographs assessed, 38 (19%) were conventional film and 162 (81%) were digital. Of the conventional film radiographs, 55% were rated 'excellent' and 37% were 'diagnostically acceptable', whilst 27% of digital radiographs were rated 'excellent' and 40% were 'diagnostically acceptable'. In the 'unacceptable' category, 33% were digital and 8% were conventional film radiographs (p <0.001).

CONCLUSIONS

The quality of digital radiographs was significantly lower compared with conventional film radiographs. The percentage of 'unacceptable' digital radiographs was above the target according to the NRPB guidelines. Hence, there is a need for improvement in quality to avoid repeat radiographs and unnecessary ionising radiation exposure. Instead of hard, printed copies, digital radiographs accompanying referrals should, within the parameters of information governance, be supplied electronically so that they may be optimised, if necessary, for better diagnostic value.

Subjective image quality comparison between two digital dental radiographic systems and conventional dental film

OBJECTIVES

Digital radiography has become an integral part of dentistry. Digital radiography does not require film or dark rooms, reduces X-ray doses, and instantly generates images. The aim of our study was to compare the subjective image quality of two digital dental radiographic systems with conventional dental film.

MATERIALS & METHODS

A direct digital (DD) 'Digital' system by Sirona, a semi-direct (SD) digital system by Vista-scan, and Kodak 'E' speed dental X-ray films were selected for the study. Endodontically-treated extracted teeth (n = 25) were used in the study. Details of enamel, dentin, dentino-enamel junction, root canal filling (gutta percha), and simulated apical pathology were investigated with the three radiographic systems. The data were subjected to statistical analyzes to reveal differences in subjective image quality.

RESULTS

Conventional dental X-ray film was superior to the digital systems. For digital systems, DD imaging was superior to SD imaging.

CONCLUSION

Conventional film yielded superior image quality that was statistically significant in almost all aspects of comparison. Conventional film was followed in image quality by DD, and SD provided the lowest quality images. Conventional film is still considered the gold standard to diagnose diseases affecting the jawbone.

RECOMMENDATIONS

Improved software and hardware for digital imaging systems are now available and these improvements may now yield images that are comparable in quality to conventional film. However, we recommend that studies still use more observers and other statistical methods to produce ideal results.

Digital radiography in the dental practice: an update

The implementation of digital imaging in dental practice should be considered. The vast number of advantages of digital imaging include time saving and image manipulation. Dose reduction is a big attraction but in practical terms this might not be fully taken advantage of, as a number of studies suggest. Challenges of images storage, back-up and exchange should be taken into account. Careful planning and integration with practice software should lead to a smooth transition. Remember, computer systems sometimes fail and contingency plans should be in place to avoid disruption to the workflow of the practice.

Radiological and histopathological evaluation of experimentally-induced periapical lesion in rats

Objective

This study evaluated experimentally-induced periapical bone loss sites using digital radiographic and histopathologic parameters.

Material and Methods

Twenty-seven Wistar rats were submitted to coronal opening of their mandibular right first molars. They were radiographed at 2, 15 and 30 days after the operative procedure by two digital radiographic storage phosphor plates (Digora^®). The images were analyzed by creating a region of interest at the periapical region of each tooth (ImageJ) and registering the corresponding pixel values. After the sacrifice, the specimens were submitted to microscopic analysis in order to confirm the pulpal and periapical status of the tooth.

Results

There was significant statistically difference between the control and test sides in all the experimental periods regarding the pixel values (two-way ANOVA; p<0.05).

Conclusions

The microscopic analysis proved that a periapical disease development occurred during the experimental periods with an evolution from pulpal necrosis to periapical bone resorption.