Accuracy of scanography using storage phosphor plate systems and film for assessment of mandibular third molars

Objectives

The aim of this study was to compare the diagnostic accuracy of two digital photostimulable storage phosphor (PSP) systems and film for assessment of mandibular third molars before surgery.

Methods

110 patients were referred to have both their mandibular third molars removed. Each patient underwent a radiographic examination with scanography using either Digora (Soredex, Helsinki, Finland) and film or VistaScan (Dürr Dental, Beitigheim-Bissingen, Germany) and film in a randomized paired design. Two observers examined the following variables on the scanograms: bone coverage, angulation of the tooth in the bone, number of roots, root morphology and the relationship to the mandibular canal. In 75 of the pairs (Digora/film pair = 38 and Vista/film pair = 37) both third molars were eventually removed. During and after surgery the same variables were assessed, which served as reference standard for the radiographic assessments. The Wilcoxon signed-rank test tested differences in accuracy (radiographic compared with surgical findings) between Digora/film and between Vista/film.

Results

There was no statistically significant difference between the diagnostic accuracy of film and either of the two digital receptors for assessment of mandibular third molars before surgery (P > 0.05), although Digora obtained a higher accuracy than film.

Conclusions

Scanography is a valuable method for examination of mandibular third molars before removal and the PSP digital receptors in this study were equal to film for this purpose.