In Vivo Evaluation of the Accuracy of Immediate Screw-Retained Provisional Crowns Fabricated Using Digital Planning and Guided Surgery

Overview

This clinical trial aims to evaluate the in vivo accuracy of a fully digital workflow for the immediate placement of a previously fabricated screw-retained provisional crown using digital planning and guided implant surgery. The study will be conducted in partially edentulous adult patients requiring the replacement of a single tooth with an immediately loaded dental implant. The main objective of the study is to assess the accuracy (trueness and precision) of the planned digital implant position and provisional restoration by comparing the virtually planned position with the actual clinical outcome after guided surgery. Emphasis will be placed on linear, angular, and rotational deviations at both the implant and provisional restoration levels. Participants will undergo a fully guided implant placement procedure with rotational control, followed by the immediate placement of a prefabricated screw-retained provisional crown designed during the digital planning phase. Postoperative intraoral scans will be obtained to register the final implant and restoration positions. The planned and achieved positions will be compared using three-dimensional analysis software to quantify deviations and determine whether the accuracy achieved remains within clinically acceptable limits.

Background Computer-guided implant surgery has consolidated a prosthetically driven approach, in which implant positioning is planned according to the definitive or provisional restoration. The integration of cone-beam computed tomography (CBCT) and intraoral scanning allows for virtual planning of implant position, axis, and prosthetic emergence. However, the accurate transfer of the digital plan to the clinical setting remains subject to cumulative errors throughout the digital and surgical workflow. Accuracy in guided implant surgery is commonly assessed by comparing the planned and postoperative implant positions using linear and angular deviation metrics. From a clinical perspective, the accuracy at the level of the provisional restoration is of particular relevance, as the restoration must seat passively without requiring significant adjustment. This requirement becomes especially critical when an immediate prefabricated screw-retained provisional crown is placed at the time of surgery, as both positional and rotational accuracy are essential for proper seating. Recent digital workflows have demonstrated the feasibility of designing and fabricating immediate provisional restorations prior to surgery. The use of guided surgical protocols incorporating rotational control aims to reproduce the planned implant orientation and facilitate the immediate placement of prefabricated restorations. However, the accuracy achievable with such workflows has not been sufficiently quantified in clinical settings. Justification Despite advances in guided surgery and digital manufacturing, limited clinical evidence exists regarding the accuracy of workflows that combine fully guided implant placement with rotational control and the immediate placement of a prefabricated screw-retained provisional crown. Quantifying plan-to-actual deviations at both the implant and restoration levels is essential to determine the clinical feasibility, predictability, and potential optimization of this protocol. Study Design This is a prospective, single-arm interventional clinical trial with an intraindividual comparison between the digitally planned implant and provisional restoration positions and the actual clinical outcomes obtained after guided surgery. Participants The study population will consist of partially edentulous patients aged 18 years or older who require the replacement of a single tooth with an immediately loaded dental implant. All participants must meet the predefined inclusion criteria and none of the exclusion criteria and must provide written informed consent prior to participation. Intervention All participants will undergo a fully digital workflow including CBCT acquisition, intraoral scanning, virtual implant planning, and the design and fabrication of a surgical guide and a prefabricated screw-retained provisional crown. Implant placement will be performed using a fully guided surgical protocol with rotational control. The provisional restoration will be placed immediately after implant insertion and kept free of occlusal contacts. Outcome Assessment Postoperative intraoral scans will be obtained with a scan body and with the provisional restoration in place. Three-dimensional analysis software will be used to compare the planned and achieved positions. Linear and angular deviations at the coronal and apical implant levels, as well as deviations of the provisional restoration, will be calculated to assess accuracy in terms of trueness and precision. Statistical Analysis Descriptive statistics will be used to summarize the deviation measurements. Normality will be assessed, and appropriate parametric or non-parametric tests will be applied to determine whether the observed deviations differ significantly from clinically acceptable thresholds.