Primary implant stability refers to the stability of a dental implant immediately after implantation. Its value is derived from a mechanical engraving of the titanium screw implant in the patient's bone tissue. High initial stabilization may be an indication for immediate loading with prosthetic reconstruction.
The value of primary implant stabilization decreases gradually with reconstruction of bone tissue around the implant in the first weeks after surgery, ceding to secondary stability. Its character is quite different from the initial stabilization, because it results from the ongoing process of osseointegration. When the healing process is complete, the initial mechanical stability is fully replaced by biological stability. The most dangerous moment for implantation success is the moment of the lowest initial stabilization, pending sufficient bone reconstruction supporting long-term maintenance of the implant. Usually this occurs during the 3–4 weeks after implantation. If primary stability was not high enough following implantation, the implant's mobility is high and can cause failure.