All-on-4 Implants

What All-on-4 is

All-on-4 is a technique for replacing a full arch of teeth with a fixed bridge supported by four implants. Two are placed vertically at the front, and two are angled at the back — the angulation is the point of the technique, because it lets the implants engage available bone and avoid the sinus in the upper jaw and the nerve in the lower.

The result is a fixed bridge you do not remove. It is not a denture that clips in, and it is not four separate crowns.

Who it suits

It is considered for people who have lost most or all of the teeth in an arch, or whose remaining teeth are failing and not worth keeping — advanced gum disease, extensive decay or repeated fractures.

It is also considered by people already wearing a full denture who want something fixed. That is a reasonable motivation, but it should follow an assessment rather than precede it: whether the technique is appropriate depends on bone volume and quality, general health, healing capacity and bite forces.

It is not automatically the right answer for a full arch. More implants, a removable implant-retained overdenture, or keeping and treating some natural teeth may be better for a given case. Any of those deserves a straight comparison.

Assessment

A CBCT scan is required, not optional. It shows bone height, width and density, and the position of the inferior alveolar nerve and the sinus floor. Angled implants are planned against that anatomy — angulation chosen from a two-dimensional radiograph is guesswork.

Planning is also restoration-driven: the implant positions follow where the finished bridge needs to be, including where the lip sits when you smile and how the bridge will be cleaned underneath.

The surgical appointment

Remaining teeth in the arch are removed, the sites are prepared, and the four implants are placed to a specified insertion torque. Adequate primary stability is what makes immediate loading possible; where that stability is not achieved, the honest course is to wait rather than load anyway.

A provisional fixed bridge is normally fitted the same day or within a day or two, which is where the phrase “teeth in a day” comes from. The provisional is exactly that — provisional. It is lighter, it is designed to be adjusted, and it carries you through healing.

From provisional to final

Osseointegration — bone bonding to the implant surface — takes three to six months and cannot be accelerated. During that period the provisional bridge is worn and a soft diet is required at first, progressing as healing allows.

The definitive bridge is made afterwards, once the tissues have settled and the provisional has confirmed the shape, length and bite. Because our laboratory is on site, the fit and shade of that final bridge are verified with the technician present.

What to be realistic about

• “Teeth in a day” describes the provisional bridge, not the finished treatment. The full course runs to several months.
• Four implants is a minimum viable configuration, not a universal one. Some arches need five or six, and being told so is a sign of careful planning rather than an upsell.
• A full-arch bridge has a different cleaning routine to natural teeth, and it depends on it. Peri-implantitis is the main long-term threat.
• Smoking and uncontrolled diabetes measurably reduce success rates.
• Acrylic on a provisional or definitive bridge can chip and teeth can wear; a bridge is a serviceable prosthesis, not a permanent object.

Alternatives

Depending on the case: individual implants and conventional bridgework where enough teeth can be saved; an implant-retained overdenture, which is removable but usually needs fewer implants and is easier to clean; or a conventional complete denture, which remains a legitimate option and the least invasive one. Single and multiple implants are covered separately.

What the cost depends on

Whether one arch or both are being treated, the number of implants actually used, whether extractions or grafting are required, the material of the definitive bridge — acrylic, composite, zirconia — and the number of provisional stages. A written proposal should separate the surgical phase, the provisional and the definitive bridge, and state what the price includes.

Maintenance

Cleaning under the bridge daily with an irrigator or superfloss is what protects the implants. Professional maintenance appointments use instruments that do not scratch the implant surface, and the bridge is periodically removed for thorough cleaning and inspection of the components. That review schedule is part of the treatment, not an optional extra.