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

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.

Inclusion criteria

• Adults aged 18 years or older.
• Partially edentulous patients requiring replacement of a single tooth with an immediately loaded dental implant.
• Patients classified as ASA I or ASA II according to the American Society of Anesthesiologists physical status classification.
• Patients with clinical conditions allowing immediate implant placement with a minimum primary stability of ≥25 Ncm.
• Ability to understand the study procedures and provide written informed consent.
• Willingness to comply with the study protocol and attend required clinical visits.

Exclusion criteria

• Patients classified as ASA III or ASA IV, or with uncontrolled systemic conditions that may interfere with study participation.
• Presence of psychiatric or cognitive disorders that may compromise informed consent or protocol compliance.
• Inability to comply with the visit schedule or required evaluations.
• Any other condition that, in the investigator's judgment, could compromise patient safety, protocol adherence, or data validity.