Implant Fixture Mounting Protocol

Two implants (SICace®, Schilli Implantology Circle, Switzerland) with 4mm diameter and 11.5 mm height were used. The abutment had 4.5 mm diameter and 8.5 mm height with 1.5 mm gingival height. First, the first fixture was mounted in a polymethyl methacrylate resin block (Orthodontic Resin, Dentsply Caulk, USA) using a surveyor. Then, the second fixture was mounted parallel to the first fixture using a surveyor, in a way that the distance between the centers of the two fixtures was 19 mm [22 (link)], in order to simulate the missing of mandibular first molar in the clinical setting [21 (link),22 (link)]. Titanium abutments were then placed on the implants using 20 N/cm torque (Fig. 1-A). A resin jig (Pattern Resin, GC, Japan) was then fabricated over the abutments. The rest of the samples were mounted using this jig. All 28 resin blocks were randomly divided into two groups of 14 for the fabrication of full contour zirconia and pre-sintered Co-Cr alloy FPDs.