All-on-4 dental implants: a fixed full set of teeth on four implants

All-on-4 replaces all the teeth in one jaw with a fixed bridge held by four dental implants, two upright at the front and two angled at the back. It suits people who have lost, or are losing, most of their teeth, including denture wearers. A provisional fixed bridge is often fitted soon after surgery when the implants are stable enough.

How All-on-4 works

All-on-4 is a way of replacing a complete arch of teeth, upper or lower, with a single fixed bridge supported by four dental implants. An implant is a small screw-shaped post, usually made of titanium, that is placed in the jawbone and acts as an artificial root. Our complete patient guide to dental implants explains single implants; this article focuses on the full-arch version.

Four implants, two of them angled

The two front implants are usually placed upright. The two back implants are placed at an angle, tilted towards the back of the mouth. This angle allows longer implants to anchor in the denser bone further forward, while avoiding the sinuses in the upper jaw and the main nerve that runs through the lower jaw. As the back implants emerge further back, the bridge is supported along most of its length.

The angled position is one of the main reasons All-on-4 can often be done without a bone graft, even when some bone has been lost. It is not always possible, though: the amount and quality of bone still decide whether four implants are enough.

A fixed bridge, not a removable denture

The new teeth are made as one piece, a full-arch bridge that usually carries around ten to twelve teeth. It is screwed onto the four implants and you do not take it out at home: only the dentist can remove it, for example during a maintenance visit. It also has no plate covering the palate, which many former denture wearers find makes eating and tasting food feel more natural.

Who All-on-4 is suitable for

All-on-4 is designed for adults who have lost all or nearly all the teeth in one jaw, or whose remaining teeth are failing and cannot reasonably be saved. Typical situations include:

• people who wear a complete denture and struggle with movement, sore spots or difficulty chewing;
• people with several loose, broken or badly decayed teeth, often after advanced gum disease, who are close to losing the rest;
• people who want fixed teeth but would prefer to avoid, or cannot have, extensive bone grafting.

General health matters more than age. Smoking, diabetes that is not well controlled, some medicines that affect bone (such as certain treatments for osteoporosis or cancer) and previous radiotherapy to the head and neck increase the risk of complications and must be discussed openly.

When the bone is very thin, a graft may still be needed, or a different implant plan may be safer; our article on when bone grafting and a sinus lift are necessary explains these procedures. In some jaws, especially when the bone allows it or the bite is very strong, the dentist may suggest six implants instead of four. You can read when All-on-6 is recommended rather than All-on-4.

Assessment and planning

Careful planning is what makes full-arch treatment predictable. It usually takes one or more appointments before surgery.

1. Examination and medical history: the dentist checks your gums, any remaining teeth, your bite and your current denture if you have one, and reviews your health and medicines.
2. Imaging: X-rays are taken, and a 3D scan of the jaw is usually requested to measure the bone and locate the sinuses and nerves precisely.
3. Records of your mouth: impressions or digital records, photographs and measurements of your bite help to plan where the new teeth should sit.
4. Planning the look and the bite: the length, shape and shade of the teeth, the support they give to your lips and the way they meet the opposite jaw are agreed with you. Sometimes a trial set-up is made so that you can see and approve the result before treatment.
5. A written treatment plan: you receive the stages, the expected timeline, the alternatives and the costs, with time to ask questions.

Surgery day and the provisional fixed bridge

The surgery is carried out under local anaesthesia, so the area is completely numb. You stay awake and feel pressure and vibration, but not sharp pain. If you feel anxious, say so at the planning stage so that the team can explain each step and agree on breaks with you.

The main steps are usually:

• removal of any remaining teeth that cannot be kept, and cleaning of the sockets;
• smoothing and shaping the bone where needed, so that the bridge has an even base;
• placing the four implants in the planned positions and checking how firmly each one is held;
• closing the gums, often with stitches.

For one jaw, the procedure often takes a few hours, depending on the number of extractions and the bone. Treating both jaws takes longer.

Immediate loading: often possible, never automatic

If the implants are firmly anchored when they are placed, a provisional (temporary) fixed bridge can usually be screwed onto them on the day of surgery or within a few days. This is called immediate loading, and it means you are not left without teeth. It depends, however, on the quality of the bone and on how stable each implant is at the time of surgery, and that can only be judged during the operation.

If the stability is not sufficient, the safer choice is to let the implants heal without load first. In that case you usually wear an adapted removable denture for a few months. This is why no responsible dentist can promise “teeth in a day” before surgery.

The first days

Swelling, bruising and soreness are normal; they usually peak around the second or third day and settle within about a week. Painkillers recommended by your dentist are usually enough, and a check-up is usually arranged within the first week or two.

Healing, the final bridge and long-term care

The healing period

The implants now need time to bond with the bone, a process called osseointegration. This usually takes around three to six months, sometimes longer. During this period the provisional bridge is lighter and less strong than the final one, so you follow a soft diet and avoid hard or chewy food on the new teeth.

The final bridge

Once the implants are stable, new records are taken and the definitive bridge is made in a dental laboratory. Several material options exist, for example acrylic or composite teeth on a metal framework, or zirconia-based bridges; each has advantages in strength, appearance and ease of repair, and the choice is made with you after examination. The final bridge is tried in, adjusted for comfort, speech and bite, and then screwed into place.

Cleaning and maintenance

A fixed bridge cannot decay, but plaque that builds up underneath it can inflame the gum and bone around the implants. This inflammation, called peri-implantitis, is the main long-term risk to any implant. Daily care usually includes:

• brushing the bridge twice a day with a soft or electric toothbrush, including along the gumline;
• cleaning underneath the bridge and around each implant with a water flosser, interdental brushes or special floss threaded under the bridge;
• regular check-ups and professional cleaning at the intervals your dentist recommends; from time to time the bridge may be unscrewed to clean it and check the implants;
• a night guard if you grind or clench your teeth.

How long it lasts

Well-integrated implants that are looked after can last for many years, often decades. The bridge teeth are subject to wear like any restoration, and the bridge may need repairs or replacement at some point, which does not usually mean replacing the implants.

Risks, limitations and alternatives

All-on-4 is a well-established treatment, but it is real surgery and carries risks. Possible problems include infection, slow healing, an implant that fails to integrate, numbness or tingling of the lip if a nerve is irritated, sinus problems in the upper jaw, a loosened screw, and chips or cracks in the bridge teeth. Because only four implants carry the whole arch, losing one of them matters more than in a plan with more implants, which is why careful planning and maintenance are so important.

Fixed teeth on four implants are not the only way to restore a jaw without teeth. According to Cleveland Clinic, a full arch is usually supported by four to six implants, and implants can hold either fixed teeth or a denture that snaps on and off. The main options compare as follows:

A well-made complete denture remains a sound choice for many people, and it can often be converted later into an implant overdenture.

What determines the cost of All-on-4

There is no single price for All-on-4, because each plan is built around your own mouth. The total cost depends mainly on:

• whether one jaw or both jaws are treated;
• the number of extractions and any gum treatment needed beforehand;
• the imaging required, such as a 3D scan;
• whether bone grafting is needed in addition;
• the implant system and the components that connect the bridge;
• the provisional bridge and the material of the final bridge.

After the examination and imaging, you receive a written plan with the cost of each stage, so that you can compare the options calmly before deciding.

All-on-4 at Ajam Dental Clinic in Tripoli

Ajam Dental Clinic is a dental practice on Fouad Chehab Boulevard in Tripoli, run by two dentists, Dr. Abdel Rahman Ajam and Dr. Soumaya Ajam. All-on-4 and All-on-6 are among the treatments offered, alongside other implant treatments, complete and partial dentures and full mouth rehabilitation. Patients come to our clinic from across Tripoli — Azmi Street, Al-Maarad, Al-Nour Square and Bab al-Ramel — as well as from Koura, Zgharta and the rest of North Lebanon.

Everything starts with a consultation: an examination, the necessary X-rays and an honest discussion about whether All-on-4 suits you or whether another option would serve you better. You can read more about the clinic and its dentists, or contact us on WhatsApp to book a consultation.

This article provides general information for patients. It does not replace an examination by a dentist, who can advise you on your own situation.