Evaluation of diagnostic accuracy of CBCT and intraoral radiography for proximal caries detection in the presence of different dental restoration materials

Abstract

Purpose: This study aimed to assess the diagnostic accuracy of cone-beam computed tomography (CBCT) and digital intraoral radiography for the detection of proximal caries adjacent to amalgam, e.max porcelain, and metal-ceramic restorations (MCRs).

Materials and methods: Parallel intraoral radiographs were obtained from 40 posterior teeth using PSP sensors. To obtain CBCT scans, the teeth were first radiographed alone, and were then positioned next to a tooth with an amalgam restoration, MCR, and e.max porcelain crown, and radiographed again. Two blinded observers scored radiographs using a four-point scale (0: absence of proximal caries, 1: enamel caries, 2: carious lesion extending to the outer half of dentin, 3: carious lesion extending to the inner half of dentin). Tooth sections were made, and the grade of caries was determined under a light microscope at x12 magnification. The sensitivity, specificity, and accuracy of CBCT and intraoral radiographs were then calculated.

Results: Artifact-free CBCT scans and intraoral radiographs had the highest diagnostic accuracy (0.826 and 0.657, respectively) while CBCT images of the teeth next to the amalgam restorations (0.526) had the lowest accuracy. The diagnostic accuracy of CBCT images of the teeth next to the porcelain crowns and MCRs was 0.613 and 0.601, respectively.

Conclusion: Artifact-free CBCT images had higher diagnostic accuracy than intraoral radiography for the detection of all grades of proximal caries. The diagnostic accuracy of CBCT images of teeth adjacent to amalgam, porcelain, and MCRs was lower compared to intraoral radiographs and artifact-free CBCT images.

Keywords: Artifact; Cone-Beam Computed Tomography; Dental Porcelain; Digital radiography.

Fig. 1

The mandible and paralleling film holder were fixed on a wooden board to standardize the radiation angle, tooth position, and position of the image receptor

Fig. 2

Sagittal (S-upper row) and axial (A-lower row) scans of (a) a tooth with enamel caries pointed by the arrow, the same tooth next to the (b) amalgam restoration, (c) metal-ceramic restoration, and (d) porcelain crown. In images b(S) and b(A), a metal artifact (arrow) caused by amalgam is seen as a radiolucent area resembling dentin caries. In image c(S), the artifact (arrow) caused by metal-ceramic restoration is seen as an area with high attenuation, covering the carious lesion. In image c(A), streak-artifact (arrow) caused by metal-ceramic restoration is seen as a lucent area resembling dentin caries

Fig. 3

Sagittal (S-upper row) and axial (A-lower row) scans of (a) a tooth with dentin caries pointed by the arrow, the same tooth next to the (b) amalgam restoration, (c) metal-ceramic restoration, and (d) porcelain crown. In images b(S) and b(A), the cupping artifact (arrow) caused by amalgam is seen as a radiopaque area which can interfere with caries detection

Fig. 4

Schematic (upper row), CBCT (middle row), and intra-oral X-ray images (lower row) of the teeth; (a) absence of proximal caries (score 0), (b) enamel caries (score 1), (c) carious lesion extending to the outer half of dentin (score 2), and (d) carious lesion extending to the inner half of dentin (score 3)

Fig. 5

Images of teeth sections under a light microscope with ×12 magnification; (a) absence of proximal caries (score 0), (b) enamel caries (score 1), (c) carious lesion extending to the outer half of dentin (score 2), and (d) carious lesion extending to the inner half of dentin (score 3). The yellow circle shows the carious lesion