All on 4 Dental Implants

Tooth loss is an important oral health problem that negatively affects chewing functions, speech clarity, and the aesthetic appearance of individuals. In cases where conventional treatment methods are not sufficient, All-on-4 implant application offers a reliable and permanent treatment option in cases of complete edentulism. This technique is a treatment protocol that has become prominent in dental implantology in recent years and whose clinical success rates have been proven by scientific studies.

What is All-on-4?

The All-on-4 dental implant procedure is an innovative protocol designed for fully edentulous patients, those with multiple missing teeth, or individuals at risk of tooth loss. This method involves securing a fixed prosthesis onto four implants—two vertical and two angled—anchored into the jawbone, maximizing existing bone support and typically eliminating the need for bone grafting. As a result, patients regain a stable dental structure that closely mimics the function and aesthetics of natural teeth."

Placement sites of 4 implants for upper and lower jaw:

For the upper jaw:

• 2 flat implants are placed in the front
• In the posterior part, 2 implants are placed at an angle of 45 degrees (to avoid damaging the sinuses)

For the lower jaw:

• Posterior implants are placed at a special angle to protect the nerves
• Natural-looking, sturdy teeth are attached to it

What is the adequate bone volume for All-on-4?

For the All-on-4 treatment to be successful, you must have sufficient quantity and quality of bone tissue in your jaw. Inadequate bone quality and quantity (insufficient for endonous implants) or severe parafunction (such as clenching/grinding) may prevent the All-on-4 procedure.

For the upper jaw (maxilla):

At least 10 mm in length and 4-5 mm in width in the anterior region. In the posterior region, a minimum bone height of 5 mm under the sinus cavity is required. The bone structure should not be too hard or too soft (ideally medium hardness).

For the lower jaw (mandible):

A minimum width of 6 mm and a length of 12 mm are required in the anterior part. There should be a minimum of 4 mm of bone above the nerve line in the posterior region. Good to moderate bone density is preferred

Solutions in case of insufficient bone:

• If the bone is too thin, bone augmentation may be necessary.
• If bone height is low, short implants or special angled placement is tried
• In extreme cases, alternatives such as the zygoma implant can be considered

In which cases can All-on-4 be applied?

Complete edentulism:

All-on-4 treatment is an excellent solution for patients who have lost most of their teeth or whose condition has deteriorated to the point that their teeth can no longer be saved

Bone loss:

Patients with significant bone loss, especially in the posterior jaw area, are suitable candidates for All-on-4 treatment. This method provides maximum efficiency from the existing bone tissue and offers the possibility of treatment without the need for long-term and costly additional procedures such as additional bone grafting (adding bone powder).

The All-on-4 technique can also be successfully applied in jaw structures with severe bone resorption (atrophy). Patients with sufficient bone support only in certain bone regions (Zone I and Zone II) in the upper jaw (maxilla) can also benefit from this treatment.

Cases with anatomical obstacles:

All-on-4 is a good solution in cases where conventional implants cannot be applied due to anatomical obstacles. It minimizes the need for bone grafts and provides functional support by bypassing anatomical limitations.

• Mandible (mandible): Anterior implants are placed at a 30-45° angle to protect the mental nerve. This technique provides stable implant support without damaging the inferior alveolar nerve canal.
• Maxilla (upper jaw): Tilt implant application is performed to avoid penetration of the sinus cavities. The maxillary sinus membrane is protected with an angled placement up to 45°.

  The search for a fast and stable solution:

The All-on-4 protocol allows the immediate installation of a temporary fixed prosthesis within the first 24 hours after surgery. This ‘rapid rehabilitation’ advantage provides a significant clinical advantage, especially for patients seeking an immediate solution to their edentulism problem.

In case of dissatisfaction with traditional dentures:

Patients who are dissatisfied with the function, comfort, or aesthetics of their existing removable dentures can benefit significantly from All-on-4, a fixed and implant-supported solution.

In search of less cost and fewer surgical procedures:

While conventional full-arch implant treatments usually require a larger number of implants and bone grafting, All-on-4 usually provides a more cost-effective and potentially less invasive treatment with four implants and by reducing or eliminating the need for grafting.

Who are not suitable for All-on-4?

Although All-on-4 implant treatment is an excellent solution for many patients, it is not recommended in some cases. Those who are not suitable for All-on-4 treatment:

  Patients with inadequate bone support:

• Patients with excessive bone resorption (atrophy) and no minimum bone volume to support implants
• Cases where adequate stability cannot be achieved despite bone graft (additional bone) application

Those with uncontrolled systemic disease:

• Diabetes (HbA1c > 7) may slow the healing process
• Osteoporosis—bone density can affect implant success
• Those with a weak immune system (cancer patients, organ transplant patients)
• Uncontrolled heart disease or bleeding disorders

Those with poor oral hygiene:

• Those with advanced periodontal disease (gingival recession)
• Smokers delay recovery and reduce the chances of success
• Patients who do not perform regular dental care and do not go to doctor controls

Those with bruxism (teeth grinding)

Severe clenching habits can cause excessive pressure on the implants, leading to failure

Psychologically unprepared

• Patients with unrealistic expectations
• People who cannot adapt to implant care

All-on-4 treatment stages:

The implementation of the All-on-4 treatment concept follows a specific protocol involving surgical and prosthetic procedures, which are carried out according to a precise plan. This approach uses only four implants for full arch restoration.

The All-on-4 treatment approach:

Conventional surgery:

This involves making an incision in the gingiva and lifting the flap, using conventional planning and a standardized All-on-4 Guide.

Guided surgery:

Correct positioning of the implants is achieved using a customized surgical template with 3D diagnosis and treatment planning. This approach can be performed without flap removal (‘flapless’).

Treatment planning:

• The patient's general health status is assessed. An intraoral examination is performed, and radiographic examinations (e.g., panoramic X-ray or tomography—CT scan) are carried out to evaluate the height, width, and quality of the bone.
• The appropriate All-on-4 approach is determined according to the available bone (standard, hybrid, or double zygoma).
• The positions and angulations of the implants are planned. The screw entry holes of the posterior implants should be in the occlusal plane of the first or second premolar or the first molar.
• The patient's smile line and vertical occlusal dimension (VOD) are evaluated.
• If directed surgery is planned, 3D software is used.
• The patient's existing or immediate prosthesis can be used for planning purposes.

Surgery:

• If necessary, flap removal or a flapless approach is applied.
• Implant sites are prepared in the jawbone. If necessary, the correct position and angulation are ensured by using the All-on-4 Guide. Implant sites in the posterior regions can be drilled at an angle up to 45°.
• The most critical factor at this stage is to ensure sufficient primary implant stability for immediate loading. If stability cannot be achieved, the traditional healing process is awaited.
• If there are extraction sites, these are thoroughly cleaned, and, if possible, the implants are placed between the extraction sockets.

Abutment connection:

Once the implants have been placed, straight or angled (at 17° or 30°) multi-unit abutments are attached to them to adjust their angle and position the screw access holes of the prosthesis correctly.If the angled implants are at 30° or more, splinting may be required.

Temporary denture (emergency loading):

• On the day of surgery, a temporary fixed prosthesis (usually acrylic) is prepared and screwed to the implants immediately after they are placed.
• This temporary prosthesis can be made using measurements taken after surgery or by modifying an existing immediate prosthesis. The prosthesis is prepared using abutment replicas, temporary caps (copings), guide pins/laboratory screws, and acrylic.
• The temporary prosthesis provides splinting by connecting the four implants together.
• This 'immediate loading' phase enables patients to have a fixed prosthesis on the day of surgery, thereby shortening treatment time ('time-to-teeth').
• The temporary denture is adjusted according to masticatory function. There should be no occlusal contact at the distal (posterior) cantilever.

Healing and follow-up:

• Osteointegration, the process by which the implants are expected to fuse with the bone, is a key aspect of the procedure. The patient is monitored regularly. Postoperative complications are usually related to overloading of the temporary prosthesis (e.g., denture fracture or abutment loosening). These problems are quickly addressed.
• Once healing is complete, the patient receives a more durable and aesthetic permanent fixed denture, which is screwed to the implants via multi-unit abutments.

All-on-4 care:

There are some important points that you should pay attention to after having the All-on-4 treatment concept.

• To ensure the success of the treatment, it is important that you are in good general health and maintain good oral hygiene. You should also maintain effective home oral care in the post-treatment period. Your dentist will teach you the specific cleaning methods suitable for your prosthesis type (fixed or removable) and oral structure. Generally speaking, implant-supported dentures are easier to maintain than conventional dentures.
• It is important to attend regular follow-up appointments with your dentist, both to check the effectiveness of your treatment and to assess your oral health. In particular, these appointments assess the effectiveness of home care to ensure that patients receive the best possible care in the comfort of their own home.
• Following surgery, a temporary fixed denture is usually screwed to the implants on the same day. Breakage of the temporary denture or loosening of the abutments can be caused by overload or unstable occlusal contacts. For this reason, you should strictly follow your physician's instructions regarding chewing or biting with the temporary denture and take special care not to put excessive pressure on the posterior (distal) extensions.
• It is normal to experience some swelling or bruising in the first ten days after surgery. However, you should contact your dentist as soon as possible if you notice any fracture of the denture or experience any discomfort or a feeling of looseness when biting down, as these may be related to overloading of the denture or occlusal imbalances.

Advantages and disadvantages of All-on-4:

Advantages:

Faster treatment and ımmediate results:

• Unlike traditional implants that require months of healing, All-on-4 often allows for immediate loading (a temporary prosthesis is placed on the same day).
• Patients leave the clinic with functional teeth, avoiding long periods without teeth.

Fewer ımplants needed:

Traditional full-arch restorations may require 6-8 implants per jaw, while All-on-4 uses only four strategically placed implants, reducing surgical complexity.

Avoids bone grafting in many cases:

• The two posterior implants are placed at an angled position (30-45°), maximizing contact with available bone, even in patients with moderate bone loss.
• This often eliminates the need for sinus lifts or bone grafts, reducing treatment time and cost.

 Lower cost compared to traditional ımplant solutions:

Since fewer implants are used and bone grafting is often unnecessary, the overall cost is lower than full-arch individual implants.

Improved quality of life:

• Patients regain 80-90% of natural bite force, allowing them to eat most foods comfortably.
• Unlike removable dentures, All-on-4 is fixed, eliminating slippage and discomfort.

 Preserves facial structure and aesthetics:

• Prevents bone resorption (jawbone shrinkage), maintaining facial contours and preventing a "sunken" appearance.
• The prosthesis is designed to look like natural teeth, enhancing smile aesthetics.

 Easier oral hygiene compared to removable dentures:

• Cleaning is simpler than with removable dentures—patients can brush and floss normally (though special care is needed around implants).

Disadvantages:

Although the All-on-4 treatment concept has many advantages and benefits, there are also some potential disadvantages, limitations, and challenges:

Not Suitable for everyone:

• Patients with severe bone loss(especially in the anterior jaw) may still require bone grafting.
• Heavy smokers or uncontrolled diabetics may have higher failure rates.

 Risk of ımplant failure (though rare):

• If an implant fails (usually due to poor osseointegration), additional surgery may be needed.
• The success of the entire prosthesis depends on all four implants integrating properly.

 Temporary denture may feel different from final restoration:

• The initial prosthesis (placed on the same day) is usually acrylic and less durablethan the final zirconia or porcelain version.
• Some patients report adjustment difficultiesin speech and chewing during the healing phase.

 Potential for dentures wear over time:

• The acrylic temporary prosthesis may require replacement after a few years.
• The final prosthesis (usually zirconia) lasts longer but may need maintenance or adjustmentsover decades.

 Limited adjustability after placement:

• Unlike removable dentures, All-on-4 is fixed, meaning adjustments must be done by a dentist.
• If the bite feels off, it may require professional modification.

All-on-4 prices:

Prices may vary depending on the clinic, city, materials used, and extent of treatment, so average ranges are given:

 Country      Price Range (Euro) 

Turkey:  4.000 -7,000€     

UK:  15,000 - 25,000€      

USA: 20,000  - 30,000 €

Germany:  12,000–20,000€        

F.A.Q.

What materials are used for All-on-4?

Implants are made of titanium or titanium alloys; prosthetic teeth are made of durable materials such as acrylic, porcelain, or zirconium.

Why is the All-on-4 price different from other implants?:

The use of fewer implants, shorter operation time, and less need for bone grafts reduces the price. However, the quality of the material used and the clinic location affect the price.

Is the All-on-4 procedure painful?

Since the procedure is performed under local anesthesia, no pain is felt during the procedure. There may be mild pain and swelling during the recovery period; these are normal.

How long is the All-on-4 treatment time?

Implant placement usually takes 1-2 hours. Temporary prostheses can be worn the same day, but it may be necessary to wait 3-6 months for a permanent prosthesis.

How long does All-on-4 last?

With proper care and regular checkups, it can be used for 20 years or more without any problems.

Can the dentures be removed?

All-on-4 dentures are usually fixed, i.e., not removable. However, cleaning is easy, and oral health is maintained with professional care.

Are aesthetic results achieved with All-on-4 treatment?

The shape, color, and alignment of the teeth are planned individually. Natural and aesthetic results are achieved with smile design.

Is there any difference between All-on-4 implants and normal teeth?

Visually and functionally, it gives results very close to natural teeth. However, it is necessary to pay more attention to oral hygiene.

Are there other options if the standard All-on-4 bone criteria cannot be met?

Yes, the standard All-on-4 criteria (required bone height and width) may not be met, especially in patients with severe bone resorption. In such cases, alternative All-on-4 approaches may be considered:

• All-on-4 Hybrid: This is the concept of using standard implants in combination with extra-maxillary implants extending to the zygomatic bone in the maxilla.
• All-on-4 Double Zygoma: It is the concept in which four extra-maxillary implants extending only to the zygomatic bone in the maxilla are used. Zygoma implants provide posterior support without the need for bone grafting.

What is the best eating plan following an All-on-4 procedure?

• After the placement of All-on-4, it is recommended that you follow your dentist's advice to manage the healing process well and prevent swelling and bleeding.
• For the first 2 weeks, liquid or pureed food should be eaten, neither too hot nor too cold.
• First 15-30 days: pasta, rice, cereals, eggs, fish, finely chopped vegetables, and soft fruits should be eaten.
• 2nd month and onwards: A normal diet should be observed, and hard foods should be avoided.