A randomized controlled trial on the efficiency of free-handed, pilot-drill guided and fully guided implant surgery in partially edentulous patients

Objectives To compare the effectiveness of free-handed (FH), pilot-drill guided (PG) and fully guided (FG) implant surgery by means of the apical global deviation (AGD) in relation to the additional financial cost and time spent. Materials and methods Thirty-three 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. Eleven patients (mean age 57; eight females; altogether 26 implants) were treated by FH surgery, 11 (mean age 53; seven females; altogether 24 implants) by PG surgery and 10 (mean age 60; six females; altogether 21 implants) by FG surgery. The accuracy in implant positioning was assessed by comparing the actual implant position to its planned position with the AGD as the main measure of effectiveness. Cost analysis included data on time investment (pre- and per-operative) and operational cost. The efficiency of PG and FG surgery was assessed by means of the incremental cost-effectiveness ratio (ICER), defined as the extra investment that is needed per unit reduction in AGD when compared to FH surgery. Results FG surgery was most effective (mean AGD: 0.97 mm) and FH surgery was least effective (mean AGD: 2.11 mm) in terms of surgical accuracy. As a result, 5/26 implants had to be restored with a cement-retained restoration following FH surgery, although screw-retention was planned for all implants in every group. The total time investment did not differ significantly between the 3 groups (p = 0.811). A significant additional cost per implant was found for PG and FG as compared to FH surgery pointing to 8.29% (euro176.54) and 10.45% (euro222.52), respectively (p < 0.001). The ICER revealed an additional cost of euro5.48 and euro4.12 per per cent reduction in AGD for PG and FG surgery, respectively. Conclusion The extra operational cost for guided implant surgery is acceptable and clinically justified since cementation can be avoided. FG surgery is the most efficient surgical approach, even though the absolute operational cost is higher when compared to PG and FH surgery