RESEARCH ARTICLE Open Access Small-diameter titanium grade IV and

titanium-zirconium implants in edentulous mandibles: five-year results from a double-blind, randomized controlled trial Frauke Müller1*, Bilal Al-Nawas2, Stefano Storelli3, Marc Quirynen4, Stefan Hicklin5, Jose Castro-Laza6, Renzo Bassetti7, Martin Schimmel1,5 and On behalf of the Roxolid Study Group Background: The aim of this study was to compare the 5-year survival and success rates of 3.3 mm dental implants either made from titanium-zirconium (TiZr) alloy or from Grade IV titanium (Ti Grade IV) in mandibular implant-based removable overdentures. Methods: The core study had a follow-up period of 36 months and was designed as a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann Bone Level implants (diameter 3.3 mm, SLActive®), one of TiZr (test) and one of Ti Grade IV (control), in the interforaminal region. This follow-up study recruited patients from the core study and evaluated the plaque and sulcus bleeding indices, radiographic crestal bone level, as well as implant survival and success 60 months after implant placement