Diagnostic accuracy of 4 intraoral radiographic techniques for misfit detection at the implant abutment joint

Abstract

Statement of problemA misfit or gap at the implant–abutment joint (IAJ) requires detection as it may compromise the health of the peri-implant tissue. However, which radiographic technique provides the most orthogonal relationship between the central beam and the implant/image receptor is unclear. PurposeThe purpose of this in vitro study was to evaluate the diagnostic accuracy of 4 intraoral radiographic techniques on misfit detection at the IAJ. Material and methodsTwenty implants were placed in polyamide jaws, and customized dental implant abutments with a metal collar were installed. Different gaps were simulated by placing one or three 50-μm-thick polyester strips at the IAJ; the absence of the strip represented the control group (no gap). The 4 radiographic techniques were evaluated by using different film holders: a periapical with bisecting angle (PBA), a bitewing interproximal (BI), a periapical with standard paralleling (PSP), and a periapical with modified paralleling (PMP) holder (with a custom-made paralleling index). A total of 240 digital radiographs were evaluated by 4 clinicians experienced with dental implants. Differences were evaluated by using receiver operating characteristic (ROC) curves (Az) and Fisher tests (α=.05). Diagnostic values (sensitivity, specificity, accuracy, and positive and negative predictive values) were also obtained. The Kappa test was used to assess intra- and interevaluator reproducibility, which ranged from moderate to almost perfect. ResultsAll diagnostic values, except specificity, were lower for the PBA technique for both the 50- and 150-μm gaps. Az values for the PBA technique were significantly lower than those obtained for the other 3 techniques (P<.05), which did not differ from each other. The 150-μm gaps were more easily detected than the 50-μm gaps only for PBA (P<.05). ConclusionsThe BI, PSP, and PMP techniques detected misfits at the IAJ most accurately. The PBA technique is not recommended for this purpose.