A Randomized Controlled Study on the Accuracy of Free-handed, Pilot-drill Guided and Fully Guided Implant Surgery in Partially Edentulous Patients

Aim: To compare the accuracy of free-handed (FH), pilot-drill guided (PG) and fully guided (FG) implant surgery.

Materials And Methods: Partially edentulous patients in need of ≥2 implants in the posterior maxilla were randomly allocated to one of the following treatment groups: FH, PG and FG. Ideal implant positions were determined in designated software following the fusion of bony information (CBCT data in DICOM format) to the prosthetic wax-up (optical scan data in STL format). The position of every implant as surgically realized was compared to its "ideal position". The apical global deviation (AGD) was the primary outcome of the study. Secondary outcome variables were angular deviation (AD), coronal global deviation (CGD), coronal lateral deviation (CLD), coronal vertical deviation (CVD), apical lateral deviation (ALD) and apical vertical deviation (AVD).

Results: Eleven patients (mean age 57; three males; eight females; altogether 26 implants) were treated by FH surgery, 11 (mean age 53; four males; seven females; altogether 24 implants) by PG surgery and 10 (mean age 60; four males; six females; altogether 21 implants) by FG surgery. FG surgery was most accurate (mean AGD: 0.97 mm; maximum AGD: 1.98 mm) followed by PG surgery (mean AGD: 1.43 mm; maximum AGD: 2.72 mm). FH surgery resulted in huge deviation from the ideal position (mean AGD: 2.11 mm; maximum AGD: 4.84 mm). The results on most secondary outcome variables followed the same order. Although screw-retained restorations were planned for all implants, five of 26 in the FH group and one of 24 in the PG group had to be restored by means of a cement-retained restoration.

Conclusion: When perfect implant positioning is required, FG surgery should be considered the gold standard approach.