Methods Used to Assess the 3D Accuracy of Dental Implant Positions in Computer-Guided Implant Placement: A Review

Abstract

The purpose of this review is to examine various assessment methods in order to compare the accuracy between the virtually planned and clinically achieved implant positions. In this review, comparison methods using pre- and post-operative computed topography (CT) data and digital impressions for definitive prosthesis will be described. The method for the displacement and strain for quantification of the error will also be explored. The difference between the planned and the actual implant placement position in guided implant surgery is expressed as an error. Assessing the accuracy of implant-guided surgery can play an important role as positive feedback in order to reduce errors. All of the assessment methods have their own inevitable errors and require careful interpretation in evaluation.

Comparison of the Accuracy of Implant Position Using Surgical Guides Fabricated by Additive and Subtractive Techniques

“…Vercruyssen et al proposed the definition of accuracy as "the deviation between the position of the 'planned' and the 'inserted' implant" (33) . Accuracy can be assessed by many (53,58,60) Pre-operative and post-operative impressions are made to fabricate dental casts. The casts are scanned, and software is used to superimpose the two scanned casts and analyze the deviation.…”

“…Pre-and post-operative CBCT (42,53,58,61,62) -3D model analysis (53) -Image replacing analysis (53) CBCT made before surgery to use in planning dental implant position. After surgery, post-operative CBCT is…”

“…The trend of placing implants has shifted from free-hand implant placement techniques to computer-guided surgical systems using surgical guides (39) . Surgical guides have been traditionally been fabricated by using radiopaque acrylic resin and vacuum-formed plastic over a duplicated diagnostic cast (53) . Using a conventional surgical guide to place dental implants has been proven to be more accurate compared to free-hand placement (54)(55)(56)(57) .…”

In Vitro Accuracy of Static Guided Implant Surgery Measured by Optical Scan: Examining the Impact of Operator Experience

“…The problem of this CT matching method is that the outline of the postoperative implant could be ambiguous due to the artifacts produced from the titanium implant material. The overall implant contour could be enlarged, making the correct identification of the implant geometry difficult [9]. A different method for examining the accuracy using the optical scan has been described [9].…”

“…The overall implant contour could be enlarged, making the correct identification of the implant geometry difficult [9]. A different method for examining the accuracy using the optical scan has been described [9]. Although commonly applied to the accuracy studies, the CT matching method was reported to be less accurate than the CAD/CAM-based measurement method by scanning the abutment placed on the implant with an intraoral scanner [10].…”