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

Official title

In Vivo Evaluation of the Accuracy of Immediate Screw-Retained Provisional Crowns Prefabricated Using Digital Planning and Fully 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.

Detailed description

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.

Interventions

• Procedure Fully Guided Implant Placement and Immediate Provisionalization
  Fully guided implant placement using a digitally designed surgical guide with rotational control, followed by immediate placement of a prefabricated screw-retained provisional crown based on the virtual treatment plan.

Primary outcome measures

• Accuracy of Implant and Provisional Crown Placement [Time frame: Immediate postoperative period]

Eligibility criteria

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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Other

Study locations

Spain · 1 center

• Complutense University of Madrid — Madrid

Publications

• Adams CR, Ammoun R, Deeb GR, Bencharit S. Influence of Metal Guide Sleeves on the Accuracy and Precision of Dental Implant Placement Using Guided Implant Surgery: An In Vitro Study. J Prosthodont. 2023 Jan;32(1):62-70. doi: 10.1111/jopr.13503. Epub 2022 Mar 22. PMID 35257456
• Ballesteros J, Vasquez-Ramos S, Revilla-Leon M, Gomez-Polo M. Immediate placement of a previously manufactured interim screw-retained implant-supported crown by using the implant position determined in the guided implant planning. J Prosthet Dent. 2025 Oct;134(4):908-913. doi: 10.1016/j.prosdent.2025.07.009. Epub 2025 Jul 30. PMID 40744851
• Yeager B, Cakmak G, Zheng F, Johnston WM, Yilmaz B. Error analysis of stages involved in CBCT-guided implant placement with surgical guides when different printing technologies are used. J Prosthet Dent. 2024 Nov;132(5):995-1004. doi: 10.1016/j.prosdent.2022.11.018. Epub 2023 Jan 21. PMID 36690552
• Younis H, Lv C, Xu B, Zhou H, Du L, Liao L, Zhao N, Long W, Elayah SA, Chang X, He L. Accuracy of dynamic navigation compared to static surgical guides and the freehand approach in implant placement: a prospective clinical study. Head Face Med. 2024 May 14;20(1):30. doi: 10.1186/s13005-024-00433-1. PMID 38745297
• Espona J, Roig E, Ali A, Roig M. Immediately loaded interim complete-arch implant-supported fixed dental prostheses fabricated with a completely digital workflow: A clinical technique. J Prosthet Dent. 2020 Oct;124(4):423-427. doi: 10.1016/j.prosdent.2019.08.008. Epub 2019 Dec 18. PMID 31862143
• Hernandez-Margarit P, Palacios-Banuelos R, Roig M, Altuna P, Blasi A. Digital workflow for designing an interim implant-supported restoration with an optimal emergence profile in an open-source software program. J Prosthet Dent. 2024 Nov;132(5):857-862. doi: 10.1016/j.prosdent.2022.10.013. Epub 2022 Dec 6. PMID 36494239
• Shah NP, Khanna A, Pai AR, Sheth VH, Raut SR. An evaluation of virtually planned and 3D-printed stereolithographic surgical guides from CBCT and digital scans: An in vitro study. J Prosthet Dent. 2022 Sep;128(3):436-442. doi: 10.1016/j.prosdent.2020.12.035. Epub 2021 Feb 12. PMID 33583616
• Chen Z, Li J, Ceolin Meneghetti P, Galli M, Mendonca G, Wang HL. Does guided level (fully or partially) influence implant placement accuracy at post-extraction sockets and healed sites? An in vitro study. Clin Oral Investig. 2022 Aug;26(8):5449-5458. doi: 10.1007/s00784-022-04512-y. Epub 2022 May 2. PMID 35499656

Identifiers

NCT: NCT07315607 · 25/700-E

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗