“How long do all on 4 implants last?”

Sorry, the only accurate answer to your question is possible from your dentist that placed the implants and prosthesis.

The longevity of All-On-Four implants is dependent on four factors: the quality of the implants; the amount of bone available; the skill of the doctor placing them, and the home care of the the patient. Ultimately, the most important factor in longevity is the home care of the patient. Implants should last a lifetime if the first three factors are good and the final factor is followed by the patient.

Depending on the bone quality, success of procedure, your medical status, any bite or jaw issues, absences of trauma to the face, i.e., car accident or assault and possible smoking habits they can vary. However, ideally the implants themselves tend to last for decades. Most "failures" are typically associated with the denture or new prosthesis breaking or failing 15 to 20 years, rather than the actual surgically placed implants themselves. The solution usually might simply be a replacement of the denture or prosthesis should that occur. A very non invasive procedure. In theory, implants are supposed to last.