The implants used were threaded, titanium oxide-surface implants with a machined collar and external hexagonal connection (Brånemark System Mk III TiUnite RP 4 mm, Nobel Biocare, Göteborg, Sweden) and the abutments used were titanium abutments (Healing Abutment Brånemark System RP , Nobel Biocare, Göteborg, Sweden). Stainless steel plates of 50, 100, 150, and 200 μm in thickness were obtained and cut in sizes of (Oguchi Shearing, Nagano, Japan). In order to create gap spaces of known dimensions, two of the plates were placed in the opposite direction between an implant and an abutment, and the abutment was screwed on the implant using a wrench at 35 N-cm of torque, as recommended by the manufacturer [Fig. 1(a)]. After the specimens were stored in room temperature for 24 h to stabilize the dimensions of the stainless steel plates, direct observation and confirmation of the actual gaps of the implant–abutment interface were accomplished by confocal laser scanning microscope (1LM21H/W, Lasertec Co., Yokohama, Japan). The parameters used for this technique were as follow; numerical aperture: 0.30, magnification: , and nominal resolution .