Technique Error Comparison with Two Digital Sensor/Paralleling Device Combinations

The use of digital sensors in intraoral radiography have created new challenges for acquiring diagnostically acceptable images. Two studies have reported intraoral technique errors with the use of a charged couple device receptor, but none have evaluated the technique effect of different sensor holding devices used in combination with a photostimulable phosphor (PSP) digital sensor. Objectives: The purpose of this study was to evaluate whether the PSP/Precision Instrument^® combination would minimize the number of technique errors compared to the PSP/extension cone paralleling (XCP^®) device. Methods: Fourteen periapical projections using the PSP/XCP^® sensor/film holder combination and 14 periapical projections using the PSP/Precision^® Instrument sensor/film holder combination were imaged on eight human skull manikins. All projections were exposed by one experienced clinician. The human skull manikins were exposed in a random order by sensor holding device. A blinded examiner evaluated each projection based on packet placement, horizontal angulation, vertical angulation, and cone centering criteria. In addition, a judgment was made regarding the diagnostic quality of the projection. Frequencies were calculated and matched pairs of data were analyzed using McNemar's test. Results: Among the 112 paired projections, no statistically significant difference was seen between the devices for packet placement (p=0.84), horizontal angulation (p=0.52), cone centering (p=0.83), or diagnostic acceptability (p=0.78). A significantly statistical difference was seen for vertical angulation with the PSP/XCP^® combination having fewer vertical errors than the PSP/Precision^® (p<0.01). Conclusion: Based on these findings using human skull manikins, the use of the PSP/XCP^® sensor/device combination compared to the PSP/Precision^® sensor/device combination may result in fewer vertical technique errors. Further research should be conducted in a patient population to determine if the vertical errors seen in this study were a result of not being able to stabilize the Precision^® instrument in the mouth.