All-on-4? All-on-5? All-on-6? How about All-on-8? How to Determine the Optimal Number of Dental Implants for Complete (Full-Arch) Teeth Replacement

Dental implants are the most effective treatment option for people who are missing teeth or those with severely damaged teeth that require complete extractions. But just how many implants do you need for full-arch restorations? The all-on-4 phenomenon has become quite popular, but is that enough for every patient? When would you consider 5, 6 or even 8 dental implants?

One of the most important factors in determining the number of implants is the type and design of the restoration they will support. This principle is known as prosthetically-driven implant dentistry. Counter-intuitively, the number of implants is not the first decision in planning the treatment, but rather the last! 

First, we must determine the patient’s needs and what type of teeth, function, and aesthetics they desire. Do they want teeth that are removable or fixed? Do they prefer teeth that mimic natural teeth with no pink prosthetics (if it’s possible to do) or a hybrid design that replaces the teeth and the pink? What type of food do they want to eat? Food on the harder side like meats and nuts, or softer food like rice and pasta? And what is their anticipated occlusal load? The load is obviously higher in a large male with strong facial muscles than in a more petite individual with smaller facial structures. Additionally, we must determine the size of their arch and the type and quantity of bone. This is a process no different than an architect who determines the requirements for the foundation of a building only after having designed the building itself first.

By now you realize that one size does NOT fit all! Treatments must be designed based on personal needs and patient attributes and not on marketing trends. The treating surgeon who is placing the implants and the restorative dentist who is restoring them must collaborate on all diagnostic findings and together design a set of teeth that meets the functional, aesthetic, biologic, and emotional requirements of the patient. Only then can they determine the number of implants necessary to meet those objectives and whether bone grafting might be indicated to support the implants.

This is called planning in reverse mode. First, consider what the patient wants, then determine the teeth design, then decide on the number of implants, and finally determine whether there is sufficient bone to support them or necessary to graft

While all the above factors should be considered in determining the number of implants, here are the range in number of implants in two types of fixed-implant supported treatment approach:

  • Hybrid design: 4, 5, or 6
  • Fixed bridge: 6 to 8*

*Depends on size of arch, occlusal  dcheme, and patient functional as well as aesthetic needs


Dr. H. Ryan Kazemi is an oral and maxillofacial surgeon in Bethesda, MD