Influence of image filters on the reproducibility measurements of alveolar bone loss

Assessment of diagnostic accuracy of a direct digital radiographic-CMOS image with four types of filtered images for the detection of occlusal caries

BACKGROUND

Digital imaging has the potential to improve diagnostic accuracy and make quantitative diagnoses. In the recent decades, software for radiographic analysis has been investigated and developed for the detection of lesions and the quantitative assessment of the depth of a caries lesion. In addition, the accuracy of diagnosis may also be enhanced by programs that filter the images. These programs can adjust the brightness and contrast, determine the gray level, invert the shades of gray, and apply pseudocolors. Few studies compared different types of digital images in the diagnosis of changes in the tooth crown.

AIM

The main aim of this study was to assess the the diagnostic accuracy of a direct digital radiography (DDR)-CMOS image with four types of filtered images for the detection of occlusal caries.

MATERIALS AND METHODS

Fifty randomly selected patients' teeth were clinically examined and digitally radiographed. Radiographed images are converted into four filter images with the help of software. Filtered images were then selected for inter- and intraobserver examination and the result was subjected to statistical analysis.

CONCLUSION

DDR-CMOS and negative image were found to be more useful in diagnosing occlusal caries.

Influence of Image Filters and Variation in Horizontal Angle of Incidence of X-ray Beam in Digital Interproximal Radiographs for Diagnosis of Secondary Caries in Esthetic Restorations

BACKGROUND

Secondary or recurrent caries are located around restoration margins or under these lesions, and can lead to tooth loss. The interproximal or bite wing radiograph is the technique of choice to assist diagnosis of secondary caries.

OBJECTIVE

To evaluate diagnostic accuracy of secondary caries in pulpal walls artificially created in extracted human premolars, observed in digital bitewing radiographs using variations in horizontal X-ray beam angle of incidence and application of enhancement filters.

MATERIALS AND METHODS

The sample consisted of 20 healthy premolars, in which secondary caries lesions were simulated by means of subjecting the pulpal wall of the cavity to wear with spherical carbide drill half, fitted to a high speed handpiece, under constant cooling, focused perpendicular to the tooth surface. The orifices were filled with wax and all teeth were restored with composite resin Filtek Z350 XT(®). Later teeth were radiographed with a digital sensor complementary metal-oxide-semiconductor (CMOS) varying the horizontal angle at intervals of 2°, covering a range of -10 to +10°.

RESULTS

The results showed that in the diagnosis of secondary caries, there was no statistically significant difference between the 2 pseudocolor filters, and negative and direct digital radiography. The pseudocolor filter no. 1 showed statistically significant differences, except at a horizontal angle of 0°, thus indicating lower efficiency in the diagnosis of secondary caries.

CONCLUSION

Secondary caries with esthetic pulp wall restoration can be diagnosed irrespective of variation in the horizontal angle of incidence of the X-ray beam. The use of different radiographic enhancement filters did not result in improved diagnosis of secondary caries.

Image enhancement of digital periapical radiographs according to diagnostic tasks

Purpose

This study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task.

Materials and Methods

Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale.

Results

There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01).

Conclusion

Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.