Which device is more accurate to determine the stability/mobility of dental implants? A human cadaver study.

Non-invasive devices including resonance frequency (RF) analysis and mobility measuring (MM) damping capacity assessment are used to measure implant stability/mobility. The aims of the study were to compare the primary stability of implant inserted into extraction sockets by using RF with cable, RF wireless and new wireless MM device, to clarify the relation between these devices and to understand the correlations between peri-implant bone levels and implant stability. A total of 30 screw-type implants (3.75 x 11 and 4.2 x 11 mm) were inserted into extraction sockets of eight mandibular pre-molar regions of human cadavers. The primary stability of implants was measured by three devices after insertion. Peri-implant vertical defects were created in millimetre increments ranging between 0 and 5 mm, and stability/mobility of implants were analysed. At placement, the mean implant stability quotient of RF with cable, RF wireless and MM device values was 46 +/- 1, 57.8 +/- 9 and -5.4 +/- 1, respectively. Statistical correlations were demonstrated between these devices (P = 0.001). Statistically significant differences were presented for all peri-implant detects ranging between 0 and 5 mm for RF with cable and RF wireless at all increments. However, only a significant decrease was found between 0 and 1 mm defects, and 4 and 5 mm defects in MM device. Although RF with cable and RF wireless seem to be suitable to detect peri-implant bone loss around implants in 1 mm increments, the new MM device may not be suitable to detect the 1 mm peri-implant bone changes in human dried cadaver mandibles.