Background: Computer-assisted implant surgery (CAIS) can facilitate accuracy of single implant placement, but little is known with regards to parallelism between multiple implants. Purpose: To compare the accuracy of position and parallelism of two implants, using static and dynamic CAIS systems. Materials and methods: Thirty patients received two implants (60 implants) randomly allocated to two different CAIS systems. Optimal implant position and absolute parallelism was planned based on preoperative cone beam CT (CBCT). Patients received implants with a surgical guide (static CAIS, n = 30) or real-time navigation (dynamic CAIS, n = 30). Implant three-dimensional deviation and parallelism was calculated after surgery. Results: The mean 3D deviation in the static and dynamic CAIS group at implant plat