Influence of Metal Guide Sleeves on the Accuracy and Precision of Dental Implant Placement Using Guided Implant Surgery: An In Vitro Study.

PURPOSE: Metal sleeves are commonly used in implant guides for guided surgery. Cost and sleeve specification limit the applications. This in vitro study examined the differences in the implant position deviations produced by a digitally designed surgical guide with no metal sleeve in comparison to a conventional one with a metal sleeve. MATERIALS AND METHODS: The experiment was conducted in two steps for each step: n = 20 casts total, 10 casts each group; Step 1 to examine one guide from each group with ten implant placements in a dental cast, and Step 2 to examine one guide to one cast. Implant placement was performed using a guided surgical protocol. Postoperative cone-beam computed tomography images were made and were superimposed onto the treatment-planning images. The implant horizontal and angulation deviations from the planned position were measured and analyzed using t-test and F-test (p = 0.05). RESULTS: For Step 1 and 2, respectively, implant deviations for the surgical guide with sleeve were -0.3 +/-0.17 mm and 0.15 +/-0.23 mm mesially, 0.60 +/-1.69 mm, and -1.50 +/-0.99 mm buccolingual at the apex, 0.20 +/-0.47 mm and -0.60 +/-0.27 mm buccolingual at the cervical, and 2.73 degrees +/-4.80 degrees and -1.49 degrees +/-2.91 degrees in the buccolingual angulation. For Step 1 and 2, respectively, the implant deviations for the surgical guide without sleeve were -0.17 +/-0.14 mm and -0.06 +/-0.07 mm mesially, 0.35 +/-1.04 mm and -1.619 +/-1.03 mm buccolingual at the apex, 0.10 +/-0.27 mm and -0.62 +/-0.27 mm buccolingual at the cervical, and 1.73 degrees +/-3.66 degrees and -1.64 degrees +/-2.26 degrees in the buccolingual angulation. No statistically significant differences were found in any group except for mesial deviation of the Step 2 group (F-test, p < 0.001). CONCLUSIONS: A digitally designed surgical guide with no metal sleeve demonstrates similar accuracy but higher precision compared to a surgical guide with a metal sleeve. Metal sleeves may not be required for guided surgery.