Straumann Variobase Abutments XC for Bridge/Bar

The Straumann Variobase Abutments XC for Bridge/Bar are prosthetic components placed on Straumann dental implants to support multi-unit bridge or bar restorations. They are made from titanium alloy (Ti-6Al-7Nb) with a violet anodized finish and feature a roughened, laser-textured chimney surface. The devices are provided non-sterile and must be steam-sterilized by the end-user before implantation.

The subject devices feature a new non-engaging implant-to-abutment interface design with flat-top geometry and internal guidance within the conical interface for both RB/WB and WB platforms. They offer expanded gingival height options (1.5/2.5/3.5 mm for RB/WB; 0.75/1.5 mm for WB), increased chimney height flexibility (7 mm reducible to 3.5 mm with visually identifiable grooves), and both straight and angled screw channel solutions. The roughened chimney surface differs from the predicate's machined surface.

ISO 10993-1 for biocompatibility, ISO 17665-1 for sterilization validation, and the FDA Guidance for Industry on Class II Special Controls for Root-form Endosseous Dental Implants and Endosseous Dental Abutments. SEM-EDX analysis was performed for surface characterization.

Substantial equivalence is based on identical material (Ti-6Al-7Nb), identical sterilization methods, and equivalent indications for use (bridge/bar restorations with screw or cement retention). The new non-engaging interface design is supported by fatigue testing demonstrating equivalent performance to the predicate. The laser-textured surface was validated through pull-off testing showing enhanced cement retention compared to machined surfaces, and SEM-EDX confirmed equivalent elemental composition despite altered surface topography.