All-on-4 Dental Implants: How Four Posts Replace a Full Arch

All-on-4 is a specific surgical protocol — not a brand name, not a marketing term — for replacing a full arch of teeth using exactly four dental implants. It was developed by Portuguese implantologist Dr. Paulo Maló in the late 1990s and has since become the most widely performed full-arch implant procedure in the world, with over two decades of peer-reviewed clinical data supporting its effectiveness.

The name describes the method precisely: all teeth on four implants.

The engineering behind the protocol

The challenge of full-arch implant dentistry has always been bone. After teeth are lost or extracted, the jawbone begins to resorb — it shrinks. The back of the jaw (the posterior region) loses bone fastest, which historically meant patients needed expensive bone grafting procedures before implants could be placed.

All-on-4 solved this by changing the geometry. Two implants are placed vertically in the front of the jaw, where bone is naturally thicker and more resistant to resorption. Two more implants are placed in the back, but angled at 30 to 45 degrees rather than straight down. This angulation achieves three things simultaneously: it maximizes contact with the available bone, it avoids anatomical structures like the maxillary sinus (upper jaw) and the inferior alveolar nerve (lower jaw), and it creates a wider spread of support for the prosthesis, reducing the mechanical cantilever effect.

The result is that most patients have enough bone for All-on-4 without any grafting — even patients who have been told they "don't have enough bone for implants" by dentists evaluating them for individual implants. The angled approach uses bone that is already there, just from a different direction.

What happens during the procedure

Before surgery

A CBCT (cone-beam computed tomography) scan maps your jawbone in 3D. Your surgeon uses this data with surgical planning software to determine the exact position, angle, and depth of each implant. Some practices use 3D-printed surgical guides — custom templates that fit over your jaw and direct the drill to the pre-planned position with millimeter precision.

Surgery day (2 to 4 hours per arch)

Remaining teeth are extracted. The implant sites are prepared according to the surgical plan. Four implants are placed — two straight in the anterior and two angled in the posterior. Impressions or digital scans are taken immediately. A provisional prosthesis (acrylic teeth on a titanium-reinforced framework) is fabricated chairside or in an on-site lab and attached to the implants. You leave with teeth.

Healing phase (3 to 6 months)

The titanium implants undergo osseointegration — the bone grows around and bonds to the implant surface. During this period, you eat normally with the provisional teeth. Soft foods for the first 2 to 4 weeks, then progressively normal diet. Virtual or in-person check-ins with your surgeon monitor healing.

Final prosthesis (return visit, 3 to 5 days)

New impressions are taken. Your permanent prosthesis — typically monolithic zirconia or acrylic-over-titanium-bar — is fabricated and fitted. Bite adjustments are made. The zirconia option is stronger, more stain-resistant, and more natural-looking. The acrylic option is lighter, easier to repair, and less expensive. Both attach to the same implant foundations.

The clinical evidence

All-on-4 is one of the most-studied protocols in implant dentistry. Published survival rates in peer-reviewed journals consistently exceed 95 percent at the 10-year mark. Maló's original study cohort has been followed for over 20 years. Complications exist — the most common are prosthesis fracture (acrylic more than zirconia), implant-level peri-implantitis (infection around an implant), and screw loosening — but these are treatable and do not typically require implant replacement.

The protocol is taught in major implant education programs (Nobel Biocare's All-on-4 certification, Straumann's Pro Arch program) and performed in over 50 countries. It is not experimental, not new, and not controversial in the implant community. It is the standard of care for full-arch fixed rehabilitation.

What All-on-4 costs

Typical 2026 ranges. US quotes frequently bundle both visits. Colombia quotes typically separate surgical visit and final prosthesis visit.

For a complete cost comparison across countries, see All-on-4 Cost by Country. For how All-on-4 compares to other full-arch options, read the complete full-arch replacement guide.