Assessment of peri-implant defects at titanium and zirconium dioxide implants by means of periapical radiographs and cone beam computed tomography: An in-vitro examination

Objective To test the accuracy of measurement of interproximal peri-implant bone defects at titanium (Ti) and zirconium dioxide (ZrO2) implants by digital periapical radiography (PR) and cone beam computed tomography (CBCT). Material and methods A total of 18 models, each containing one Ti and one ZrO2 implant, were cast in dental stone. Six models each were allocated to following defect groups: A-no peri-implant defect, B-1 mm width defect, C-1.5 mm width defect. The defect width was measured with a digital sliding caliper. Subsequently, the models were scanned by means of PR and CBCT. Three examiners assessed the defect width on PR and CBCT. Wilcoxon signed-rank test and Wilcoxon rank sum test were applied to detect differences between imaging techniques and implant types. Results For PR, the deviation of the defect width measurement (mm) for groups A, B, and C amounted to 0.01 +/- 0.03, -0.02 +/- 0.06, and -0.00 +/- 0.04 at Ti and 0.05 +/- 0.02, 0.01 +/- 0.03, and 0.09 +/- 0.03 at ZrO2 implants. The corresponding values (mm) for CBCT reached 0.10 +/- 0.11, 0.26 +/- 0.05, and 0.24 +/- 0.08 at Ti and 1.07 +/- 0.06, 0.64 +/- 0.37, and 0.54 +/- 0.17 at ZrO2 implants. Except for Ti with defect A, measurements in PR were significantly more accurate in comparison to CBCT (p <= 0.05). Both methods generally yielded more accurate measurements for Ti than for ZrO2. Conclusions The assessment of interproximal peri-implant defect width at Ti and ZrO2 implants was more accurate in PR in comparison to CBCT. Measurements in CBCT always led to an overestimation of the defect width, reaching clinical relevance for ZrO2 implants.