Stepwise Modified Transcrestal Sinus Floor Elevation in Sites With 3-5-mm Residual Bone Height: A Retrospective Study

Area of Science:

• Oral and Maxillofacial Surgery
• Dental Implantology
• Bone Grafting Procedures

Background:

• Sinus floor elevation is crucial for dental implant placement in atrophic maxillas.
• Residual bone height (RBH) of 3-5 mm presents a challenge for standard sinus lift techniques.
• Comparing transcrestal and lateral approaches is essential for optimizing outcomes.

Purpose of the Study:

• To compare the clinical and radiographic outcomes of stepwise modified transcrestal sinus floor elevation (SM-TSFE) versus lateral sinus floor elevation (LSFE).
• To evaluate implant survival rates, sinus membrane perforation, and bone loss in patients with 3-5 mm RBH.
• To identify risk factors associated with implant failure and perforation.

Main Methods:

• Retrospective study of 149 patients undergoing simultaneous implant placement with SM-TSFE (n=69) or LSFE (n=80).
• Follow-up period: 6 months to 8 years.
• Clinical outcomes: implant survival, membrane perforation, complications. Radiographic outcomes: RBH, marginal bone loss (MBL), vertical bone height.

Main Results:

• Comparable cumulative implant survival rates between SM-TSFE (91.30%) and LSFE (93.75%).
• Significantly lower sinus membrane perforation rate in the SM-TSFE group (7.24%) compared to LSFE (18.75%).
• Maxillary sinus septa identified as a major risk factor for perforation; TiUnite surface and membrane perforation increased implant failure risk.

Conclusions:

• SM-TSFE provides comparable implant survival to LSFE in sites with 3-5 mm RBH.
• SM-TSFE offers a significant safety advantage with a substantially lower rate of sinus membrane perforation.
• This technique enhances predictability and safety for short residual bone height cases.