Influence of tube current, sharpening filters, and metal artefact-reducing filters on the diagnosis in the cone-beam computed tomographic diagnosis of carious lesion.

OBJECTIVES

To evaluate artefact-reducing filters as a means to optimize and ensure the accuracy of carious lesion diagnosis testing in 2 experimental models (presence and absence of adjacent metallic objects).

METHODS

Fifty molar teeth were used, randomly divided into 5 groups (n = 10): G1-Sound teeth; G2-Carious teeth; G3-teeth with Class I cavity preparation restored with resin (Cl I + R); G4-Cl I + R with the use of a hyperdense lining material; and G5-Cl I + R with the use of a hypodense lining material. The Carestream CS 9600 tomograph was used, testing 2 experimental models (presence and absence of adjacent metallic objects), with tube voltages of 100 kV and 120 kV, voxel sizes of 75 and 150 µm, and applying the metal artefact reduction (MAR) filter. Three examiners scored according to the Likert scale. The Fleiss' kappa test was performed to analyse intra- and inter-examiner agreement, in addition to Cochran's Q test with a significance level of 5%, to compare the parameters of tube voltage, voxel size, and MAR filter.

RESULTS

The Fleiss' kappa test showed excellent inter- and intraobserver agreement for all groups. All modalities of tube voltage, voxel size, and MAR filter showed very high accuracy, sensitivity, and specificity, providing diagnoses consistent with reality, achieving 99% accuracy when the model did not present adjacent metallic objects to the tooth, and 95% accuracy when such objects were present.

CONCLUSIONS

It is concluded that, although cone-beam computed tomography is not the exam of choice for diagnosing carious lesions, optimizing acquisition parameters and using MAR filters allows a reliable concomitant diagnosis in exams already indicated for other purposes.