Smart Lift Technique for Minimally Invasive Transcrestal Sinus Floor Elevation

Introduction In the posterior maxillary sextants, insertion of implants of desired length and diameter is often limited by the dimensional alterations of the residual ridge as well as the pneumatization of the maxillary sinus occurring after tooth loss. Transcrestal sinus floor elevation (tSFE) represents a surgical option to vertically enhance the available bone in the posterior maxillary sextant through an access created through the edentulous bone crest. Surgical techniques for tSFE are mainly based on the fracture or perforation of the sinus floor by means of osteotomes or burs. The apical displacement of the Schneiderian membrane obtained by tSFE may be enhanced and better maintained by condensing a graft material under the elevated sinus membrane. Pjetursson and colleagues compared the outcomes of tSFE when performed with osteotomes with and without the additional use of deproteinized bovine bone mineral (DBBM). At 1 year post-surgery, periapical radiographs at grafted sites were more frequently associated with a radio-opaque structure apical to the implants compared with nongrafted sites. After an average followup time of 3.2 years, a significantly greater gain in radiographic bone height was observed in grafted (4.1 mm) compared with nongrafted (1.7 mm) sites, with a twofold higher probability to observe a substantial (2 mm) gain in height over the implant apex when a graft material was used. Recently, we proposed a minimally invasive procedure for tSFE, namely the Smart Lift technique, which is characterized by a transcrestal access to the sinus cavity by means of specially designed drills and osteotomes. The procedure represents a modification of the technique proposed by Fugazzotto. However, the major novelty is that all the instruments are used with adjustable stop devices, thus restricting the working action of burs and osteotomes to the vertical amount of residual bone. This is aimed to prevent any accidental penetration of instruments into the sinus cavity. Previous studies showed that the Smart Lift technique results in a predictable apical displacement of the sinus floor and a limited postoperative morbidity, when used in association with graft biomaterials. With the Smart Lift technique, the vertical augmentation of the implant site is provided by the condensed trephined bone core that is displaced into the sinus.