Adjunctive Benefit of Xenograft Plus a Membrane During Sinus Crestal Approach

Patients in need for implant-supported restoration in maxillary posterior sites with insufficient residual bone height will be randomly allocated to two different arms. Crestal sinus lift with simultaneous implant placement will be performed in both groups. Control group: crestal sinus lift with no adjunctive biomaterial; Test group: crestal sinus lift associated with xenogenic bone graft and collagen membrane; Six months after implant placement, implants will be loaded with definitive screw-retained prostheses. Six months later, patients will be recalled for clinical and radiographic assessment.

Patients in need for implant-supported restoration in maxillary posterior sites with bone deficiencies will be randomly allocated to two different arms. Full-mouth periodontal chart and standardized radiographs will be evaluated at the time of inclusion. Crestal sinus lift with simultaneous implant placement will be performed in both groups. Control group: crestal sinus lift with no adjunctive biomaterial; the healing abutment in this group is made up of PEEK (poly-ether-ether-ketone). Test group: crestal sinus lift associated with xenogenic bone graft and collagen membrane; the healing abutment in this group is made up of titanium; Resonance frequency analysis will be performed at the time of implant placement and at 1, 3, 6 months of follow-up. Both healing abutment will be undersized: this characteristic will allow to harvest a 1mm-wide biopsy of the transmucosal tract at the end of the healing phase (6 months). Six months after implant placement, impression will be taken and implants loaded with definitive screw-retained prostheses. Six months later, patients will be recalled for clinical and radiographic assessment.

Implant site preparation with detachment of Schneiderian membrane and subsequent implant placement. The corresponding healing abutment is made up of PEEK (poly-ether-ether-ketone)

Implant site preparation with detachment of Schneiderian membrane. After that, collagen membrane plus xenogenic bone substitute will be placed into the site before implant placement. The corresponding healing abutment is made up of titanium.

After surgical exposure of maxillary alveolar crest, implant site preparation and transcrestal detachment of Schneiderian's membrane will be performed. Thereafter implant will be placed, protruding in the maxillary sinus with its apical part.

Before implant placement, xenogenic collagen membrane and bone granules will be pushed under the Schneiderian's membrane through the surgical site.

the amount (mm) of crestal bone resorption after implant placement assessed through intraoral radiographs

Inclusion Criteria: more than 18 years old edentulous in posterior maxilla patient in need of sinus augmentation procedure residual bone height greater than 3mm Exclusion Criteria: systemic chronic diseases affecting osseointegration contraindication for implant therapy less than 18 years uncontrolled periodontitis smoker (more than 10 cig/day)