Accuracy of Static Computer-assisted Implant Surgery in Distal Free-end Scenarios

Technological advances have influenced the approach to implant treatment. One of the fields presently experiencing rapid development is static computer-assisted guided surgery (sCAIS), which allows transfer of the virtual implant planning to the mouth of the patient, based on the use of a surgical guide. In sCAIS there is a deviation between the virtually planned implant position and the actual position of the implant placed during surgery. A recent review analyzed only fully guided implants and recorded a mean coronal horizontal deviation (CHD) of 1.12 mm (standard deviation \[SD\] = 0.08), a mean apical horizontal deviation (AHD) of 1.41 mm (SD = 0.1), a mean vertical deviation (VD) of 0.12 mm (SD = 0.23), and a mean angular deviation (AD) of 3.58º (SD = 0.2). The aim of the present study was to compare the accuracy of CAD-CAM and conventional guides in candidates for distal free-end implant treatment, and to analyze the effects of possible confounding factors inherent to the patient or the surgical technique employed.A prospective, controlled and blinded quasi-experimental study was carried out involving 27 patients with 76 implants distributed into two groups according to the surgical guide manufacturing approach used: conventional (control group \[CG\]) or CAD-CAM (test group \[TG\]). The implants were planned virtually with the planning software, and the surgical guides were manufactured. Fully guided implant placement was carried out, and the deviations were measured along with other secondary variables as potential confounding factors.