All on Four

The term All-on-4 refers to “all” teeth being supported “on four” dental implants. This procedure allow the replacement of missing teeth with a permanent, screw-retained, same-day replacement for the entire upper and / or lower set of teeth with a bridge or denture. The procedure is best for patients with significant tooth loss or decay and for people whose bone loss in the jaw area prevents them from getting conventionally oriented (vertical) dental implants. Often, tooth loss is accompanied by loss of the jaw bone which poses the problem of reconstruction of the jaw bone requiring bone grafting. The All-on-4 technique takes advantage of the dense bone that remains in the front part of the jaws and by placing the two posterior implants on an angle to avoid the sinus cavities in the upper jaw and the nerve canal in the lower jaw. For the implementation to be successful a careful analysis of the bone structure needs to be made. The most ideal way to evaluate the bone is by a CBCT scan and digital planning. The All-on-4 protocol is for at least four implants to be placed in a jaw. The back implants are typically angled approximately 30 to 45 degrees from the biting plane. The implant is placed in front of the maxillary sinus in the upper jaw (maxilla) and in front of the mental nerve in the lower jaw (mandible). The head of the implant emerges in approximately the second premolar position. This will allow a molar tooth to be cantilevered posterior resulting in a denture or bridge with approximately 12 teeth.