Does Implant Connection Design Affect Interpretation of Radiographic Images?

Abstract Aims: Detection of marginal gaps at the implant-impression coping interface before impression-making is a common clinical task in prosthodontic treatment. Dental radiography is the most commonly used method for intraoral detection of gaps. The objective of this study was to assess the effect of implant connection design on the detection of experimentally-created marginal gaps at the implant-impression coping interface at various tube angulations. Methods: The impression coping with a 0.5 mm space was screwed onto three implant systems (Branemark (B), Nobel Replace (NR) and Nobel Active (NA)). Overall, 54 digital X-rays were taken with vertical and horizontal inclines of -20°, -10°, 0°, 10° and 20°. Ten prosthodontists examined the radiographs without using magnification. Data were analyzed using Chi-square and Fisher’s exact tests. A two-way random model and absolute agreement was used to evaluate the intra class correlation coefficient (ICC) (p-value<0.05). Results: The mean specificity was 0.7 in system B, 0.9 in system NA and 0.5 in system NR. The mean sensitivity was 0.9 in B, 0.3 in NA and 0.7 in NR systems. Youden’s statistic value was 0.6 for B, 0.1 for NA and 0.3 for NR. Conclusions: Radiography is a reliable diagnostic test for system B but not for systems NA or NR. Positive or negative angulation direction had no effect on the resolution of radiographs in the three connection types. Moreover, vertical radiation angulation in the absence of a gap and horizontal angulation in the presence of a gap affects radiograph resolution and the clinicians’ diagnosis.