a b s t r a c t a r t i c l e i n f oMethods: 60 rough surface implants were placed in 4 bovine ribs. 30 standard and 30 prototype implants were divided to group A and B, respectively. All were inserted with a torque of 30 N/ cm2, so that the rough/smooth interface was placed at bone crest level (the distance between the implants needed to be at least 4 mm). Primary stability was measured by resonance frequency analysis (RFA) with the Osstell ISQ transducer directly to the implant or over three Smartpeg screwed to the top of three different healing abutments of 2, 3.5 and 5 mm of height. Results:The mean ISQ of the prototype group is 73.9 ± 5.3 and of the standard one is 79.8 ± 3.7.