What Are the Differences Between All-on-4 and All-on-6?

All-on-4 and All-on-6 replace a complete dental arch with a fixed prosthesis without placing one implant for every missing tooth. The obvious difference is whether four or six implants are planned in one jaw. Yet the number alone does not determine success. Implant position and spread, primary stability, prosthesis length and material, bite design, access for cleaning and lifelong maintenance are equally important.

The International Team for Implantology consensus on complete-arch fixed prostheses recommends at least four appropriately distributed implants for a one-piece fixed full-arch prosthesis. It also reports no statistically significant implant-survival difference in the available evidence between restorations supported by fewer than five implants and those supported by five or more. This does not mean four implants suit everyone or that six are unnecessary. Each jaw requires an individual surgical and prosthetic decision.

At-a-glance comparison

Who may be assessed?

These treatments may be considered for patients who are fully edentulous or whose remaining teeth have a poor long-term prognosis because of severe decay, fracture or advanced periodontal disease. Healthy or treatable teeth should not be removed merely to fit a package. Tooth preservation, implant-supported bridges, a removable implant overdenture or a conventional denture may be valid alternatives.

Assessment should include:

• Dental and periodontal examination, including infection control

• Panoramic imaging and, when indicated, three-dimensional cone-beam CT

• Maxillary sinuses, mandibular nerve canals and jaw boundaries

• Bone volume and quality and the planned anterior–posterior implant spread

• Lip support, smile line, speech, restorative space and vertical dimension

• Natural teeth, dentures or implants in the opposing jaw

• Clenching, grinding and high bite forces

• Smoking, diabetes, immune status, medicines and previous radiotherapy

• Manual dexterity, oral hygiene and access to long-term reviews

A photograph, panoramic image or online consultation cannot establish the definitive number of implants. Even three-dimensional imaging is not enough on its own; the surgical plan must be developed from the intended definitive prosthesis.

When might All-on-4 be considered?

All-on-4 may use the most favourable bone and, when appropriate, tilt posterior implants to avoid the sinus or mandibular nerve while improving the support spread and controlling cantilever length. Fewer implant sites may reduce surgery and cost for some patients. However, implant position, primary stability and passive prosthetic fit are especially critical, leaving little tolerance for poor planning.

Loss of one implant can materially affect support and may require temporary removal, redesign or an additional implant. That contingency should be discussed before treatment. Claims such as “always graft-free with four implants” or “permanent teeth for everyone in one day” are not reliable.

When might All-on-6 be considered?

Where bone and anatomy permit, six implants may offer broader load distribution, a shorter cantilever and, in some cases, a segmented prosthetic design. They may provide more restorative options if a single implant later develops a problem. This can be considered in selected patients with a long arch, high bite forces or a prosthetic design that needs additional support.

Six is not automatically better. Placing two extra implants in unfavourable positions can reduce hygiene access or increase the need for grafting. The ITI consensus notes that bone augmentation may be required when the prosthetic plan calls for greater implant distribution or number. Surgical complexity, overall cost and maintenance may also increase.

What does “fixed teeth in a day” mean?

Connecting a fixed provisional prosthesis on the day of implant placement or soon afterwards is called immediate loading. It is usually not the definitive prosthesis. The ITI consensus on placement and loading protocols advises considering patient factors, primary stability at each site, any need for augmentation, bite protection and clinician experience.

If adequate stability is not achieved, extensive grafting is performed or risk is high, loading may need to be delayed. A provisional restoration requires a softer diet and controlled bite during healing. After healing, gums, speech, aesthetics and occlusion are reassessed before the definitive prosthesis is made.

Prosthetic material and design

Passive fit and a cleanable design matter as much as the implant count. Options can include acrylic or composite teeth on a metal or titanium framework, monolithic zirconia and other hybrid designs. Each has trade-offs in weight, repairability, wear, sound, aesthetics and cost.

There must be access beneath the prosthesis for a toothbrush, interdental brush, special floss or an appropriate water irrigator. The American College of Prosthodontists guidance on full-arch implant restoration maintenance emphasises plaque control, hygienic prosthetic contours and risk-based professional maintenance to limit biological and mechanical complications.

Risks and long-term maintenance

Both approaches can involve:

• Failure to integrate or later loss of an implant

• Infection, peri-implant mucositis or peri-implantitis with bone loss

• Pain, swelling, bleeding, nerve injury or sinus-related complications

• Cracking or fracture of provisional or definitive teeth, wear or screw loosening

• Bite, speech or aesthetic problems

• Inadequate access for cleaning, trapped food and odour

NHS dental implant information explains that implants may fail to join with bone, components may loosen or wear, and smoking increases some risks. Active periodontal disease should be treated; glucose control, medicines and overall health must be assessed. Bite adjustment and a night guard may be considered for grinding.

A fixed prosthesis is not maintenance-free. Daily cleaning, regular dental and hygiene reviews, appropriate radiographs and mechanical checks are required. Bleeding, swelling, a bad taste, discharge, prosthesis movement, a crack or a changed bite should be assessed promptly.

Treatment in Türkiye and Clinicly’s role

Before travelling, an international patient should share examination and imaging records, medical conditions, medicines, allergies and any previous implant details. A written plan should clarify:

• The proposed number of implants in each jaw and the rationale

• Which teeth are to be preserved or extracted

• The possibility of grafting or a sinus procedure

• Whether the provisional prosthesis will be fixed or removable

• Definitive material, delivery conditions and likely visit stages

• Implant and prosthetic component brand/model and future part availability

• Included and excluded services and conditions for additional treatment

• Complication management and follow-up after returning home

Clinicly Health Tourism supports secure file transfer to authorised providers in Türkiye, communication with an appropriate dental team, written plans and quotations, appointments, interpreting, transfers and follow-up coordination. Clinicly is not a dental clinic; it does not diagnose, choose the implant number or guarantee an outcome. Clinical decisions belong to the authorised dentist and restorative team who assess the patient. Provider status can be checked on the Ministry of Health list of authorised healthcare providers and facilitators.

Do not schedule a return flight immediately after surgery. Allow time to review bleeding, swelling, pain, the provisional prosthesis and the bite, and obtain the surgeon’s fitness-to-fly advice. Before returning home, collect the implant passport, surgical report, component details, images, prescriptions, hygiene instructions, emergency contact and review schedule.

Frequently Asked Questions

1. Is All-on-6 always better than All-on-4?

No. Six implants may provide support and design advantages in selected patients, but the outcome depends on bone, distribution, stability, prosthetic design, hygiene and risk factors.

2. Can four implants support a fixed full arch?

Yes. Four appropriately distributed and stable implants may support a one-piece fixed full-arch prosthesis in a properly selected case.

3. Are permanent teeth fitted on the same day?

The same-day prosthesis is usually provisional. Immediate fixed loading is possible only when implant stability and a protected bite are adequate; the definitive prosthesis follows healing.

4. Does All-on-4 always avoid bone grafting?

No. It may reduce grafting in some anatomies, but deficient bone, infection or the prosthetic plan can still make augmentation necessary.

5. Must all remaining teeth be extracted?

No. Teeth that can be predictably preserved should be assessed. Extraction is considered only for teeth with a poor prognosis and an agreed prosthetic plan.

6. Is the same implant number used in the upper and lower jaws?

Not necessarily. Bone quality, anatomy, arch form, opposing dentition and prosthetic design are assessed separately for each jaw.

7. Which prosthetic material is best?

No single material is best for everyone. Aesthetics, bite, weight, repairability, hygiene access, available space and cost must be balanced.

8. How is a fixed full-arch prosthesis cleaned?

Brush at least twice daily and clean underneath with interdental brushes, special floss or a suitable water irrigator, together with professional maintenance.

9. What happens if one implant fails?

The team assesses prosthetic support and implant positions. Reduced loading, repair or redesign, implant removal or a replacement implant may be needed.

10. Which documents should I receive before going home?

Obtain the surgical report, implant passport and component details, images, prescriptions, provisional and definitive prosthetic plan, hygiene instructions, warning signs and follow-up schedule.

Conclusion

Choosing between All-on-4 and All-on-6 is more complex than choosing four or six. The objective is a cleanable and repairable restoration that preserves treatable teeth, respects anatomy, provides adequate implant distribution and stability and can be followed long term. The final decision requires an in-person examination, three-dimensional imaging and integrated surgical-restorative planning.