Short implants placed with or without grafting into atrophic sinuses: the 5-year results of a prospective randomized controlled study.

Abstract

Over 5years, (i) to evaluate the clinical efficiency of 8-mm implants placed with osteotome sinus floor elevation (OSFE) in extremely atrophic maxillae and (ii) to compare bone levels around implants placed with and without grafting. TE® SLActive® implants (Institut Straumann AG, Basel, Switzerland) were placed in sites with a residual bone height (RBH) of ≤4mm. Before surgery, sinuses were randomized to receive anorganic bovine bone (control) or no graft (test). After 10weeks of healing, implants were functionally loaded with single crowns. Bone levels were measured from standardized peri-apical radiographs. Thirty-seven (17 test, 20 control) implants were placed in 12 patients (RBH: 2.4±0.9mm). Two early and one late failures occurred. The success rate was 91.9% (94.1% test, 90.0% control). All implants gained endo-sinus bone (3.8±1.0mm test, 4.8±1.2mm control; P=0.004). Mean crestal bone loss (CBL) was 0.6±1.1mm, without a significant difference between the groups (P=0.527). Mean bone gain and CBL did not change significantly between 1 and 5years (P=0.249 and P=0.293, respectively). Atrophic posterior maxillae can be predictably rehabilitated using OSFE with a simultaneous implant placement. The new bone formed around implants after 1year was stable after 5years, irrespective of the presence or the absence of graft. Grafting was unnecessary to achieve an average bone augmentation of 3.8mm, but more bone was gained with grafting.