Accuracy Assessment of Immediate and Delayed Implant Placements Using CAD/CAM Surgical Guides
The aim of this study is to assess the accuracy of immediately placed implants using Anatomage Invivo5 computer-assisted design/computer-assisted manufacturing (CAD/CAM) surgical guides and compare the accuracy to delayed implant placement protocol. Patients who had implants placed using Anatomage Invivo5 CAD/CAM surgical guides during the period of 2012–2015 were evaluated retrospectively. Patients who received immediate implant placements and/or delayed implant placements replacing 1–2 teeth were included in this study. Pre- and postsurgical images were superimposed to evaluate deviations at the crest, apex, and angle. A total of 40 implants placed in 29 patients were included in this study. The overall mean deviations measured at the crest, apex, and angle were 0.86 mm, 1.25 mm, and 3.79°, respectively. The means for the immediate group deviations were: crest = 0.85 mm, apex = 1.10, and angle = 3.49°. The means for the delayed group deviations were: crest = 0.88 mm, apex = 1.59, and angle = 4.29°. No statistically significant difference was found at the crest and angle; however, there was a statistically significant difference between the immediate and delayed group at the apex, with the immediate group presenting more accurate placements at the apical point than the delayed group. CAD/CAM surgical guides can be reliable tools to accurately place implants immediately and/or in a delayed fashion. No statistically significant differences were found between the delayed and the immediate group at the crest and angle, however apical position was more accurate in the immediate group.

Pre-operative cone beam computerized tomography image with the virtual implant position and the tooth to be extracted.

(a) After approval of treatment plan, the manufacturer fabricates a stereolithographic model, called Anatomodel, on which a customized surgical guide will be made. (b, c) A customized preabricated acrylic crown was made prior to surgery for the purpose of potential immediate temporization. (d) In the event of not achieving primary stability with 35 Ncm insertion torque, an interim removable prosthesis was fabricated.

Customized computer-assisted design/computer-assisted manufacturing (CAD/CAM) surgical guide intra-operatively. (a) After extracting the tooth, CAD/CAM surgical guide is seated, sleeve diameter accommodates the drill guides and implant diameter. (b) A reduction handle is used to accommodate smaller diameter drills prior to implant insertion. (c) Implant placed immediately after extraction with a minimum primary stability of 35 Ncm torque. (d) Prefabricated screw-retained provisional crown delivered and left out of occlusion.

Immediate implant placement cases: schematic illustration. A superimposed image between pre- (silver) and postop (turquoise) implant positions. Green line represents point C (deviation at crest), red line represents point A (deviation at apex), and the angle formed between the blue and light red lines represents angle A (deviation of the axis).

Pre-operative and postoperative cone beam computerized tomography images superimposed with deviations measured.

Delayed implant placement cases. The final casts at the time of restoration were used as postop measures and superimposed to pre-op cone beam computerized tomography images with the virtual implants after digital scanning.
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