Intra- and inter-observer agreements in detecting peri-implant bone defects between periapical radiography and cone beam computed tomography: A clinical study

Abstract

Background/purpose: Information regarding agreements between periapical radiograph (PA) and cone beam computed tomography (CBCT) in detecting peri-implant defect is still scarce. The aim of this clinical study was to compare agreements between PA and CBCT in detecting peri-implant bone defect.

Materials and methods: This retrospective clinical study enrolled 32 patients with both PA and CBCT filmed right after implant placement. Four modalities were used for film reading: PA1 (original), PA2 (enhanced brightness/contrast), CBCT1 (selected axial and mesial-distal direction images) and CBCT2 (all data with software). 2 experienced and 2 inexperienced observers scored all films. Intra- and inter-observer agreements were estimated with Cohen's kappa coefficient. Categorized agreements were compared and differences among four modalities were calculated.

Results: Agreements of PA were better than CBCT when detecting peri-implant bone defects in inter-observer agreements (median kappa 0.471 vs. 0.192; p = 0.016). Moreover, agreements in experienced observers were better than inexperienced observers (median kappa 0.883 vs. 0.567; p < 0.001). There was significant difference among four modalities except for experienced observer 2 (p = 0.218).

Conclusion: Agreements of PA are better than CBCT when detecting peri-implant bone defects, especially for inter-observer agreements. Experienced observers are more consistent in assessment than inexperienced ones.

Keywords: Cone beam computed tomography; Dental implants; Peri-implant bone defect; Periapical radiography.

Figure 1

Intra- and inter-observer agreements of each observer for PA1 (original periapical radiography), PA2 (enhanced brightness/contrast periapical radiography), CBCT1 (selected axial and mesial-distal direction images) and CBCT2 (all data with software).

Figure 2

Spearman correlation between final score of each patient and proportion of CBCT.

Figure 3

A, B, and C were the three patients with peri-implant bone defect identified by all 4 observers (red arrows point to the defects). D and E were the two patients with lowest scores (yellow arrows point to the artifacts with decreased gray value, while blue arrows point to the artifacts with increased gray value). Notice the upper incisor in D, artifacts with increased gray value were located at mesial and distal direction, while artifacts with decreased gray value was located at mesial-lingual and distal-lingual direction. Image sequence was PA1 (original periapical radiography), PA2 (enhanced brightness/contrast periapical radiography), CBCT axil view and CBCT mesial-distal view (from left to right).