Over the past year I have incorporated the use of resonance frequency analysis (RFA) to help determine when an implant is ready for loading. I wanted to prevent the infrequent situation where the restorative dentist and patient have invested much time and expense in creating a final abutment and crown, to unfortunately find a non-integrated implant during abutment screw tightening.
The first FRA device clinically available was the Osstell. It has undergone many changes over the past several years and now is very user friendly.
The RFA is a bending test of the implant-bone interface, where a transducer applies an extremely small bending force that is transmitted as a lateral force to the implant and then its displacement is measured.
The most recent device is wireless, where a metal rod (peg) is connected to the implant by means of a screw and it is excited by magnetic pulses elicited from a handheld computer. This diagnostic device has been extensively used in experimental and clinical research for the last 10 years and has demonstrated a good correlation between the obtained ISQ (implant stability quotient) values and the degree of stiffness between the implant and the bone.
It is great to have an objective way to assist in determining osseointegration and when to load an implant. You can be assured that when I send a patient back for restorative procedures the implant ISQ value will indicate a high level of implant rigidity. Most well integrated implant have a value about 70 or greater.