Accuracy of implant placement based on pre-surgical planning of three-dimensional cone-beam images: a pilot study

Aim: To evaluate the precision of transfer of a computer-based three-dimensional (3D) planning, using re-formatted cone-beam images, for oral implant placement in partially edentulous jaws. Material and Methods: Four formalin-fixed cadaver jaws were imaged in a 3D Accuitomo FPD (R) cone-beam computed tomography (CT). Data were used to produce an accurate implant planning with a transfer to surgery by means of stereolithographic drill guides. Pre-operative cone-beam CT images were subsequently matched with post-operative ones to calculate the deviation between planned and installed implants. Results: Placed implants (length: 10-15 mm) showed an average angular deviation of 2 degrees (SD: 0.8, range: 0.7-4.0 degrees) as compared with the planning, while the mean linear deviation was 1.1 mm (SD: 0.7 mm, range 0.3-2.3 mm) at the hex and 2.0 mm (SD: 0.7 mm, range 0.7-2.4 mm) at the tip. Conclusions: Cone-beam images could be used for implant planning, taking into account a maximal 4 degrees angular and 2.4 mm linear deviation at the apical tip.