Clinical and radiographic evaluation of the long-term success of implants placed with various maxillary sinus lift techniques: A retrospective study

In cases of insufficient bone height in the posterior maxilla, maxillary sinus lift surgery is considered a reliable treatment option for dental implant placement. In recent years, the open sinus lift technique without grafting has gained popularity due to its lower treatment cost and reduced complication risk. This retrospective study included patients who underwent single-stage sinus lift surgery with implant-supported fixed prosthetic restorations due to inadequate bone height in the posterior maxilla. The patients were divided into two groups according to the applied surgical technique. Group 1 consisted of patients who underwent open maxillary sinus lift without grafting and simultaneous implant placement, while Group 2 included those who received open sinus lift with grafting or closed (transcrestal) sinus lift procedures. Demographic data, implant dimensions and characteristics, residual bone height, anatomical location, and follow-up duration were evaluated. The primary outcome variable was implant survival, whereas secondary outcome variables included implant success rate, mesial and distal marginal bone loss, bone gain, and the presence of prosthetic complications. The study comprised 168 patients (72 females [42.9%], 96 males [57.1%]) aged 33–83 years (mean age: 58.42 ± 10.89 years), with a total of 316 implants. Of these, 61.4% (n=194) were in Group 1, and 38.6% (n=122) were in Group 2. During the follow-up period, 12 implants (6.2%) failed. Residual bone height was significantly higher in Group 2 (p=0.001), while implant diameter and length were significantly greater in Group 1 (p=0.039; p<0.001). Significant differences were also observed between the groups regarding gender distribution (p=0.003) and anatomical location (p=0.023). When outcome variables were compared, the success and survival rates were 88.7% and 95.9% in Group 1, and 83.6% and 96.7% in Group 2, respectively, with no statistically significant difference between groups (p>0.05). Bone gain was significantly higher in Group 1 (3.12 ± 1.91 mm) than in Group 2 (2.06 ± 1.25 mm) (p=0.001). However, no significant difference was found in mesial and distal marginal bone loss (p>0.05). The rate of prosthetic complications was 18.6% in Group 1 and 22.1% in Group 2, with no significant difference between groups (p=0.439). Within the limitations of this study, the findings indicate that the long-term survival and success rates of the graftless open sinus lift technique are comparable to those of grafted or closed sinus lift methods. Given its advantages in terms of cost-effectiveness and lower complication risk, this technique may be considered a predictable and reliable treatment option in appropriately selected cases. Keywords: Maxillary Sinus Lift, Implant Success and Survival, Bone Gain