Purpose: To compare the clinical, radiographic outcomes and patient satisfaction of short‐6‐mm implants and longer implants combined with osteotome sinus floor elevation (OSFE). Materials and Methods: Two hundred and twenty‐five patients with 225 implants were included and randomly assigned into three groups (each group: 75 implants) using randomizing table method: group 6 mm (6 mm implants alone), group 8 mm + O (8 mm implants + OSFE) and group 10 mm + O (10 mm implants + OSFE). Outcomes measures were as follows: implant survival, complication, resonance frequency analysis measurement, surgical time, bleeding on probing (BOP), pocket probing depth (PPD), modified plaque index (mPI), marginal bone loss (MBL) and patient satisfaction. Results: The dropout rate was 3.6% at 1 year. Implant survival rates were 96%, 100% and 100% in group 6 mm, group 8 mm + O and group 10 mm + O, respectively. In group 6 mm, the survival rates of implants with diameter of 4.1 mm were 90% (27/30), while the survival rates of implants with diameter of 4.8 mm were 100% (42/42). The surgical time (min) in group 6 mm was significantly shorter than those in group 8 mm + O and group 10 mm + O (13.6 ± 2.2, 19.4 ± 3.7 and 18.3 ± 4.3, respectively, p = 0.03). No significant differences in ISQ values, BOP, PPD, mPI and MBL were found among three groups. Significant higher value of intra‐operative discomfort was found in group 6 mm (p = 0.02). Conclusion: All treatment options provided acceptable clinical and radiographic results up to 1 year after loading. The current 1‐year results must be confirmed by longer follow‐ups of at least 5 years. [ABSTRACT FROM AUTHOR]