Purpose: To compare planning and patient rehabilitation using a 3D dental planning software and dedicated surgical guides with conventional rehabilitation of partially or fully edentulous patients using flapless or mini-flap procedures and immediate loading. Materials and methods: Fifty-one fully or partially edentulous patients requiring at least 2 implants to be restored with a single prosthesis, having at least 7 mm of bone height and 4 mm in bone width, had their implant rehabilitation planned on three-dimensional (3D) cone beam computed tomography (CBCT) scans using a dedicated software. Afterwards they were randomised according to a parallel group study design into two arms: computer-guided implant placement aided with templates (computer-guided group) versus conventional implant placement without templates (conventional group) in three different centres. Implants were to be placed flapless and loaded immediately; if inserted with a torque over 35 Ncm with reinforced provisional prostheses, then replaced, after 4 months, by definitive prostheses. Outcome measures, assessed by masked assessors were: prosthesis and implant failures, complications, peri-implant bone level changes, number of treatment sessions, duration of treatment, post-surgical pain and swelling, consumption of pain killers, treatment time, time required to solve complications, additional treatment cost, patient satisfaction. Patients were followed up to 1 year after loading. Results: Twenty-six patients were randomised to the conventional treatment and 25 to computerguided rehabilitation. No patient dropped out. One provisional prosthesis failed, since one of the two supporting implants failed 11 days after implantation in the conventional group (P = 1.0). Four patients of the conventionally loaded groups experienced one complication each, versus five patients (6 complications) in the computer-guided group (P = 0.726). There were no statistically significant differences between the two groups for any of the tested outcomes with the exception of more postoperative surgical pain (P = 0.002) and swelling (P = 0.024) at conventionally treated patients. Conclusions: When treatment planning was made on 3D CBTC scan using a dedicated software, no statistically significant differences were observed between computer-guided and a free-hand rehabilitations, with the exception of more postoperative pain and swelling at sites treated freehand because more frequently flaps were elevated. Keywords: computer-guided surgery, dental implants, flapless surgery, immediate loading Conflict of interest statement: This trial was completely self-funded and there are no conflicts of interests.