Accuracy of Complete-arch Implant Scans Obtained Using T-Marker

Overview

This randomized crossover clinical study will evaluate and compare the accuracy and effective scanning time of complete-arch implant scans obtained using the (TruAbutment,Marker) T-Marker photogrammetry application operated on a smartphone and a tablet. Twenty-four patients with completely edentulous arches rehabilitated with four well-integrated implants connected to multiunit abutments will undergo both digital impression protocols in a randomized sequence. A verified conventional implant cast will serve as the reference standard. Linear and angular deviations between the implant positions obtained using each digital protocol and the reference model will be evaluated using three-dimensional analysis software. Effective scanning time required for implant coordinate acquisition and registration will also be recorded. The study will determine whether the use of T-Marker with a smartphone provides accuracy and scanning efficiency comparable to its use with a tablet.

Complete-arch implant scanning is challenging because of the large interimplant distances and the limited availability of stable anatomical landmarks, which may result in cumulative image-stitching errors. Photogrammetry-based workflows have been introduced to improve the accuracy of implant position recording. T-Marker is a photogrammetry application that uses external optical markers and image-acquisition protocols to determine implant positions. This randomized crossover clinical study will compare two T-Marker acquisition devices: a smartphone and a tablet. Each participant will undergo both digital impression protocols, with the order of the protocols randomized to minimize potential order and operator-learning effects. A verified conventional splinted implant impression will be used to fabricate a master cast, which will be digitized using a calibrated laboratory scanner to generate the reference dataset. T-Marker optical markers will then be attached to the multiunit abutments, and complete-arch implant position data will be acquired using either an iPhone 15 Pro Max or a tablet. The resulting digital datasets will be compared with the reference dataset using three-dimensional analysis software. Linear and angular deviations will be evaluated to determine the trueness of the implant position measurements. Effective scanning time, defined as the time required to acquire and register all implant positions using the photogrammetric acquisition mode, will also be recorded. Surface and soft-tissue scanning, STL export, and data-merging procedures will not be included in the scanning-time measurement.