Test implants originating from various manufacturers were investigated. Straumann sandblasted, large-grit, acid-etched (SLA)® tissue level standard implants (Straumann AG, Basel, Switzerland) with the following diameter: length configurations were 3.3–12 mm (RN connection), 3.3–4.1 mm (RN connection), and 4.8–8 mm (WN connection), Ankylos Cell Plus® surfaced B-implant types (Dentsply Implants, Mannheim, Germany) with the following diameter: length configurations used were 4.5–8 mm and 4.5–9.5 mm, and Biomet 3i Full Osseotite® Tapered Certain implants (Biomet 3i, Barcelona, Spain) with a 4-mm diameter/13-mm length were investigated.

Test implants were imbedded using Duromod B® dual component polyurethane resin (Dumont Instruments, Brussels, Belgium) in a silicon mould with a bar-shaped recipient (approximal dimensions (length × width × height): 16 cm × 2.5 cm × 3 cm)). Per bar, five implants were imbedded using system-specific implant mounts allowing correct vertical positioning. After resin polymerization, all implants were given an identification number in order to allow transfer of the measurement outcomes to the datafile.

A fresh implant system-specific Smartpeg® (Integration Diagnostics AB, Säveden, Sweden) transducer was connected to each implant using a manual torque controlling device set at 8 Ncm (Tochnichi, Ota-Ku, Tokyo, Japan). For Straumann implants, Smartpeg type # 04 and, for Ankylos implants, Smartpeg type # 16 were used. For 3i Tapered Certain implants, Smartpeg type # 15 was used.

Smartpeg excitation was performed by using the Osstell IDx device. The cabled probe of the Osstell IDx was positioned towards the most coronal part of the Smartpeg by the aid of a stand (Mitutoyo 70105N, Mitutoyo, Santo Amaro, Brazil) (Fig. 2). The measured ISQ value was noted and input in the datafile.

The speed of vibration, v(t), of an excited Smartpeg was measured by means of a portable laser vibrometer (laser class 2) (Polytec PDV 100, Polytec, Irvine, CA, USA), generating a focusable laser beam (λ = 640 nm), mounted on a tri-pod with a three-way tilting head (Manfrotto, Cassolo, Italy) allowing for easy and precise laser beam orientation in X, Y, and Z directions. The measurement range was set at 20 mm/s with a sensitivity of 5 mm/s. The generated laser beam was orientated towards a flat surface of the hexed part of an implant-mounted Smartpeg. Correct positioning of the laser beam orientation was by visual inspection of laser dot position on a flat surface of the Smartpeg hexagon and by using the reflection index on the laser scanning vibrometer device.