Diagnosis of VRF on CBCT in the presence of dental implant: will an inclination of the mandible reduce the impact of artifacts?

Abstract

The presence of a dental implant close to a tooth with suspected vertical root fracture (VRF) may hinder the diagnosis of this condition on cone beam computed tomography (CBCT) exams, due to the formation of artifacts generated by the implant. Thus, the objective of the present study is to evaluate the impact of the variation of the anteroposterior inclination of the mandible in the detection of VRF, when a zirconia dental implant (artifact generator) is present in a region posterior to the tooth, in the same hemiarch. A phantom will be made from a partially edentulous eviscerated human mandible and two cervical vertebrae, included in ballistic gelatin. A zirconia implant will be placed in the region of tooth 46. An empty socket in the region of tooth 44 will alternately harbor 20 teeth (with and without VRF) for evaluation. Tomographic acquisitions of the phantom will be made at different anteroposterior angles (0º, 30º, and 45º). The phantom will be rebuilt between acquisitions to change the inclination of the mandible. The exams will be saved in a random order for viewing on Ondemand3D software. The images will be evaluated by 3 Oral and Maxillofacial radiologists, on a 5-point scale in relation to the presence of VRF. For analyses, the Kappa test and the calculation of the area under the ROC curve (Az) will be used. Wilcoxon test will be used to compare the values of Az obtained for the different angulations. For data analysis, software PASW Statistic (Version 17.0; SPSS Ins, Chicago, IL) will be used and significance level will be set at p<0.05.