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

Three-Dimensional printed model for preclinical training in oral radiology

INTRODUCTION

3D printing is experiencing significant growth in the teaching and learning process. This study aims to present a 3D printed skull model for preclinical intraoral radiographic practice.

MATERIALS AND METHODS

Two 3D printed mannequins were created. One mannequin used an STL file of a skull that was edited using two 3D modelling software (Meshmixer and Netfabb). The second mannequin was designed directly from a patient's segmented CBCT data and then converted into an STL file. Both mannequins were printed using fused deposition modelling (FDM) technology and polylactic acid (PLA) filament; teeth for the second mannequin were also printed using digital light processing (DLP). The printed skull bones were attached, the mandible was articulated to the articular fossa of the temporal bone, and the teeth were inserted into the alveoli. Intraoral radiographs of both mannequins were taken using a digital sensor (RVG 5100, Carestream).

RESULTS

Both 3D printed mannequins showed satisfactory radiographic appearance, allowing geometric representation of each intraoral radiographic projection, regardless of STL file origin. Anatomical structures, such as the periodontal ligament space, zygomatic process of the maxilla and intermaxillary suture, were represented. The material cost of the first and second printed prototype was $34.00 and $39.00, respectively.

CONCLUSIONS

The use of 3D printed models is presented as an alternative to artificial commercial phantoms for the preclinical training of intraoral radiographic techniques through the combined benefits of superior radiographic projection quality, the possibility of model manipulation and an affordable price.

Comparison of technical errors in pediatric bitewing radiographs acquired with round vs rectangular collimation

OBJECTIVE

To compare technical errors in bitewing radiographs acquired with round vs rectangular collimation in a hospital-based pediatric dentistry training program.

STUDY DESIGN

A retrospective chart review was conducted of 176 digital bitewing radiographs exposed with round collimation and 106 exposed with rectangular collimation. The number of re-exposures was calculated, and errors in central ray entry (CRE; "cone cuts"), horizontal and vertical positioning, and angulation were measured.

RESULTS

There were no greater re-exposures but significantly more CRE errors with rectangular collimation (21.7%; n = 23; 95% confidence interval [CI], 13.9%-30.0%) than with round collimation (3.4%; n = 6; 95% CI, 0.7%-6.1%). CRE error location, horizontal positioning errors, and size of horizontal overlapped contacts were statistically different but not clinically important.

CONCLUSIONS

Use of rectangular collimation resulted in increased CRE errors but no other clinically significant problems. This technique should be used to reduce radiation exposure to patients.