Resonance Frequency Analysis of Sinus Augmentation by Osteotome Sinus Floor Elevation and Lateral Window Technique

To evaluate the use of resonance frequency analysis (RFA) to quantitatively compare the stability of implants placed in the atrophic posterior maxilla using 3 sinus augmentation techniques: osteotome sinus floor elevation (OSFE) and 1- and 2-step lateral window techniques (LWTs).

Data were retrospectively collected from 50 patients, 29 to 85 years old. One hundred twenty-eight implants were subdivided based on sinus augmentation technique as determined by available native bone height. Thirty-three implants were placed using OSFE in at least 8.0 mm of bone. Forty-four implants were synchronously placed using 1-step LWT in 3.0 to 7.9 mm of bone. In cases with less than 3.0 mm of bone, the 2-step LWT was performed and the remaining 51 implants were placed after a period of healing. Implant stability quotient (ISQ) was recorded from RFA at stage 1 and subsequently at stage 2 (follow-up) 3 to 12 months later. Statistical analysis was completed using t test and analysis of variance to assess differences in implant stability over time and among techniques, respectively.

ISQ values at placement averaged 70.9, 68.9, and 72.2 for OSFE, LWT, and LWT with delayed placement, respectively. These differences were not statistically significant (P = .2). At stage 2 (follow-up), average ISQ values were 76.7, 77.7, and 78.7 for OSFE, LWT, and LWT with delayed placement, respectively. These differences were not statistically significant (P = .3). In contrast, differences in ISQ at stage 2 (follow-up) versus stage 1 were statistically significant for all 3 techniques (P < .01). OSFE, 1-step LWT, and 2-step LWT yielded average increases in ISQ of 5.8, 8.8, and 6.5, respectively.

The results support the use of OSFE, 1-step LWT, and 2-step LWT to augment bone in the atrophic edentulous posterior maxilla. All 3 methods provide predictable osseointegration and yield statistical increases in ISQ at stage 2 (follow-up) compared with time of placement. With appropriate case selection according to native vertical bone height, there are no statistical differences in ISQ among these 3 techniques at either stage.