Purpose: To compare planning and patient rehabilitation using 3D implant planning software and dedicated surgical templates with conventional freehand implant placement for the rehabilitation of partially or fully edentulous patients using flapless or mini-flap procedures and immediate loading. Materials and methods: Patients requiring at least two implants to be restored with a single prosthesis, having at least 7 mm of bone height and 4 mm in bone width were consecutively enrolled. Patients were randomised according to a parallel group study design into two groups: computerguided group or conventional freehand group. Implants were loaded immediately with a provisional prosthesis, replaced by a definitive prosthesis 4 months later. Outcome measures assessed by a blinded independent assessor were: implant and prosthesis failures, any complications, marginal bone levels, number of treatment sessions, duration of treatment, post-surgical pain and swelling, consumption of pain killers, surgical and prosthetic time, time required to solve complications, and patient satisfaction. Patients were followed up to 5 years after loading. Results: Ten patients (32 implants) were randomised to the computer-guided group and 10 patients (30 implants) were randomised to the freehand group. At the 5-year follow-up examination one patient of the computer-guided group and one of the freehand group dropped-out (both moved to another country). No prostheses failed during the entire follow-up. Two implants failed in the conventional group (6.6%) vs none in the computer-guided group (P = 0.158). Ten patients (five in each group) experienced 11 complications (six in the computer-guided group and five in the freehand group), that were successfully solved. Differences between groups for implant failures and complications were not statistically significant. Five years after loading, the mean marginal bone loss was 0.87 mm ± 0.40 (95% CI: 0.54 to 1.06 mm) in the computer-guided group and 1.29 mm ± 0.31 (95% CI: 1.09 to 1.51 mm) in the freehand group. The difference was statistically significant (difference 0.42 mm ± 0.54; 95% CI: 0.05 to 0.75; P = 0.024). Patient self-reported post-surgical pain (P = 0.037) and swelling (P = 0.007) were found to be statistically significant higher in patients in the freehand group. Number of sessions from patient's recruitment to delivery of the definitive prosthesis, number of days from the initial CBCT scan to implant placement, consumption of painkillers, averaged surgical, prosthetic, and complication times, were not statistically significant different between the groups. At the 5-year followup, all the patients were fully satisfied with the function and aesthetics of their definitive prostheses. Conclusions: Both approaches achieved successful results over the 5-year follow-up period. Statistically higher post-operative pain and swelling were experienced at sites treated freehand with flap elevation. Less marginal bone loss (0.4 mm) was observed in the computer-guided group, at 5 years follow-up. Keywords: computer-guided surgery, dental implants, flapless surgery, immediate loading Conflict-of-interest statement: This trial was completely self-funded and all the authors declare no conflicts of interest.