Diagnosis of approximal caries after delayed scanning of photostimulable phosphor plates

Statement of the Problem: Considering the high diagnostic accuracy and wide dynamic range of photostimulable phosphor plates [PSPs], they can be a good alternative for radiographic films

Purpose: This study was aimed to assess the effects of delay in scanning PSPs on the diagnostic accuracy of detection of approximal caries

Materials and Method: Radiographs from fifty-two extracted molar and premolar teeth were radiographed using DIGORA PSP [Soredex Corporation, Helsinki, Finland]

The teeth were either intact or with non-cavitated approximal caries. The plates were scanned immediately [time zero] and at 10 min, 30 min, 60 min and 120 min after exposure. Sixty-five images were obtained and evaluated for presence or absence of approximal caries by two oral and maxillofacial radiologists and 2 restorative specialists. The diagnostic accuracy of approximal caries detection was measured using a 5-point rating scale. Definite presence of caries was confirmed using a stereomicroscope. Analysis of caries detection data was performed by calculating sensitivity and specificity using repeated measures with ANOVA

Results: Significant differences were found in complete negative predictive value, absolute negative predictive value and complete dentine sensitivity value between different scan times [p< 0.05]

These values were significantly different at 10 min, 60 min and 120 min [p< 0.05]

However, immediate scan and 30 min delay were not significantly different [p> 0.05]

The accuracy of approximal caries detection at 120 min was less than at 60 min and at 60 min was less than at 30 min. Conclusion: In order to detect approximal caries more accurately, DIGORA PSPs should be scanned within 30 min after exposure

[Accuracy of panoramic radiographs in determining the relationship of posterior root apices and maxillary sinus floor by Cone-Beam CT]

It is crucial to verify the relationship between root apices and maxillary sinus floor in some surgical procedures like extraction and implant placement or in orthodontic movements like intrusion. Protrusion of roots into the sinus increases the risk of post extraction pneumatization which in turn decreases the available bone at the implant or denture sites. The aim of this study was to determine the panoramic radiology accuracy for defining the relationship between posterior root apices and the maxillary sinus floor by Cone Beam CT [CBCT]. Paired panoramic radiographs and CBCT images of 117 subjects were examined. 452 posterior maxillary roots including second premolar, first and second molar were classified by the means of the relationship with maxillary sinus floor. CBCT was used as Gold standard method, and the agreement of panoramic findings with CBCT was examined statistically. Data were analyzed using Chi-square and Multiple logistic regressions. Agreement of the panoramic and CBCT results were seen in 57.7% of all cases. Roots which had no contacts with the sinus floor [class 0] showed a high agreement of 89.5% between two imaging techniques. Roots in contact with sinus floor [class 1] showed 58.8 % and cases with root protrusion into sinus cavity [class 3, 4] showed 50% of agreement [P<0.001]. Also in 36% of cases with no protrusion into the sinus cavity [class 0, 1, 2], panoramic showed protrusion. The agreement for the premolar was higher than molars [P<0.001]. The majority of roots which their images were projected on the sinus cavity had no vertical protrusion in CBCT cuts. Considering the results, in these cases CBCT can be recommended