Incremental, Transcrestal Sinus Floor Elevation With a Minimally Invasive Technique in the Rehabilitation of Severe Maxillary Atrophy. Clinical and Histological Findings From a Proof-of-Concept Case Series

In the posterior maxillary sextants, the residual dimensions of the edentulous ridge can considerably limit the insertion of implants with the desired length and diameter. A minimally invasive procedure for transcrestal sinus floor elevation (tSFE), namely the Smart Lift technique, which is based on a standardized sequence of specifically designed drills and osteotomes, was introduced in 2008 and subsequently validated in a series of recent studies. The present technical note describes the use of the technique by a staged approach, called incremental tSFE (i-tSFE), in the augmentation of severely resorbed edentulous ridges. The i-tSFE consists of 2 staged tSFE procedures performed with a transcrestal access, the second of which is performed concomitantly with implant placement. In the present case series, 3 patients with severe bone atrophy (residual bone height, 2 to 3 mm) in the edentulous posterior maxilla were treated with i-tSFE. At the second surgical stage of i-tSFE, implants at least 8 mm long were placed at all sites, and the success of the implant-supported restoration was monitored to 6 months (1 patient) or 3 years (2 patients). Histologic findings from an augmented site showed the presence of newly formed bone, bone marrow spaces with numerous vascular canals, and residual graft particles occupying approximately 50%, 15%, and 35% of the total area, respectively. The results of the study showed that i-tSFE can be performed successfully with the Smart Lift technique to rehabilitate atrophic maxillary posterior sextants.