Comparative evaluation of radiographic density of different endodontic material

The purpose of this study was to evaluate and compare the densities of four different brands of root canal sealers using three different intraoral imaging receptors. Four different root canal sealers used were – AH Plus (Dentsply Germany, Resin based), Epiphany (Pentron USA, Resin based), U/P (Sultan Healthcare, Zinc oxide eugenol based) and Apexit (Ivoclar / Vivadent, Calcium hydroxide based). The sealers were mixed according to manufacturer instructions and six specimens of each material were fabricated. All the specimens were imaged using three different intraoral #2 sized imaging receptors-D and E speed film and storage phosphor plates. D and E speed films were digitized and stored in JPEG format. All the images were exported into the Image J software (rsb.info.nih.gov/ij/) and the mean grey values and integrated density of each material was calculated from four random areas of each image and averaged. Mixed model ANOVA was performed. Pair wise comparison of mean grey values between the three imaging receptors and integral densities recorded by the receptors showed high statistical significance for all the four different root canal sealers. Results showed that the four different types of root canal sealers showed different optical densities on all the three receptors. The purpose of this study is to evaluate and compare the optical densities of four different brands of root canal sealers using three different intraoral imaging receptors.

Exploring digital filters for internal root resorption: how can we improve the diagnosis of small lesions?

Objectives: This study aimed to evaluate the impact of enhancement filters in detecting small simulated internal root resorptions (IRR). Methods: : forty-two extracted human teeth were sectioned, connected, and stored in a dry human jaw and x-rayed with Photostimulable Phosphor Plates (PSPs), composing the control group (CG). In the middle third of the root canals, IRR lesions were simulated using Da Silveira protocol. After, the specimens were x-rayed to create the test group (TG). All images acquired were exported with seven enhancement filters plus the original image. Three examiners used a five-point Likert scale to evaluate the images regarding the presence/absence of IRR. Diagnostic efficacy was assessed from sensitivity and specificity results. Comparison among filters was performed by using receiver operating characteristic (ROC) curve analysis. Results: : moderate values of Kappainterexaminer (0.403–0.620) and high values of Kappa-intraexaminer (0.757–0.915) were observed. The best performance occurred in the CG (p < 0.05). Original images presented the greatest sensitivity and area under the ROC curve (0.595–0.750), while the Endo filter presented the greatest specificity (0.952). Inversion and Pseudo3D images produced the greatest doubt in the diagnosis, significant for CG with the Pseudo-3D filter (p < 0.05). Conclusions: : the Original and ‘Endo’ filters should be chosen as it offers greater diagnostic ability and allows more confidence during the evaluation.

Investigating the Effect of Different Metal Sheets on Reducing Radiation Behind Intraoral Digital Phosphor Plates During Intraoral Radiography using Gray Value

Purpose: To assess the efficacy of metal sheets with different thicknesses on reducing the radiation behind the photostimulable phosphor plate (PSP) during intraoral periapical examinations. Materials and Methods: In this study, a phantom head was used to investigate the effect of using metal sheets of aluminum, stainless steel, and copper with three thicknesses of 0.5, 0.75 and 1mm on reducing the radiation behind PSP. Images were acquired at 66 kVp 8 mA, and 0.16 s using the long-cone paralleling technique. The images were saved and exported to DICOM format without any post-processing. Then, they were transferred to an image processing software (Mimics, Materialize, Leuven, Belgium), and their mean gray values (MGV) were determined. The acquired data were statically analyzed for accessing the significant difference in groups means using ANOVA, and the means of groups were compared using Tukey’s test procedure. Results: The MGV of the second PSP differed significantly from those PSPs slotted with various metals (p<0.001). The MGV for lead and stainless steel at 0.5 mm thickness was insignificant (p = 0.852), but differed significantly from other metals. The MGV for PSPs with 0.75 mm stainless steel and 1 mm copper slots were varied significantly from those of all other PSP and metals. The 1 mm copper group was significantly different from all other groups (p<0.001). Conclusion: Using the mean gray value of the PSP, the use of various metal sheets of different thicknesses could effectively reduce the radiation behind the PSPs during periapical radiographs.

Analysis of the deterioration of photostimulable phosphor plates

Objectives: To assess, objectively to determine the deterioration of the photostimulable phosphor plates (PSPs) after several acquisitions. Methods: Two new PSPs without preliminary use were exposed with an intraoral X-ray unit, and the EXPRESS® (Instrumentarium Imaging, Tuusula, Finland) unit was used for scanning of the PSPs. A 12-stepwedge aluminum scale were used superimposed with the PSPs during the X-rays exposures to perform the objective analyses. Objective analysis was carried out by mean gray values using the Image J software through a region of interest (ROI) of 0.1 × 0.1 mm, and the data were analyzed statistically using ANOVA. Results: For each, the Express® PSP a total of 1800 images were acquired during 60 days. The objective analysis showed loss of the mean gray values between the initial and final images. Besides, the percentage of mean gray values’ loss was between 0.7%, for the thickest step, and 8.4%, for the lowest thickness step. Conclusion: After many X-ray exposures of the Express® PSP a singular deterioration in the mean gray values could be observed.

The way we were (and how we got here): fifty years of technology changes in dental and maxillofacial radiology

The history of the last 50 years (1970–2020) of technological changes and progresses for equipment and procedures in dental and maxillofacial radiology is related from the insider perspective of an industrial physicist and technologist who has been instrumental at innovating and developing medical equipment in different parts of the world. The onset and improvement of all major categories of dental and maxillofacial radiographic equipment is presented, from the standpoint of their practical acceptance and impact among common dentists and maxillofacial radiologists: X-ray sources and detectors for intraoral radiography, and panoramic systems, both film-based and digital (including photo-stimulated phosphor plates); and cone beam CT.