All-on-4 is a full-arch tooth replacement technique that uses just four strategically placed implants to support a fixed bridge of teeth. For patients who are missing all or most of their teeth on an arch, it offers a permanent, non-removable alternative to conventional dentures — usually without requiring a bone graft.
This article explains what All-on-4 is, why the technique works, what the clinical evidence shows, how it compares to All-on-6, and what to expect in terms of cost and candidacy in Malaysia.
The origin of the All-on-4 concept
The All-on-4 technique was developed by Portuguese oral surgeon Dr. Paulo Malo at the Malo Clinic in Lisbon. He treated his first documented patient using the finalised protocol in 1998. The concept was later commercialised and trademarked by Nobel Biocare as the All-on-4® Treatment Concept, and in 2023, Nobel Biocare awarded Dr. Malo for 25 years of the technique.
The central problem the technique was designed to solve: patients with severe tooth loss often also have significant jawbone atrophy — the bone shrinks when teeth are missing. Traditional implant placement in atrophied bone required major bone grafting procedures, long healing periods, and significant additional cost and risk. Dr. Malo's insight was that this bone grafting could often be avoided entirely by changing the angle of the posterior implants.
Why four implants can support a full arch
The geometry of the All-on-4 concept relies on a specific arrangement of four implants:
- Two anterior (front) implants are placed vertically in the anterior jaw, where bone volume is typically best preserved even after tooth loss.
- Two posterior (rear) implants are placed at an angle of up to 45 degrees, tilted toward the front of the arch. This tilt is the key biomechanical feature of the technique.
The tilting serves two purposes. First, it allows the implants to use available anterior bone rather than the resorbed posterior regions — avoiding proximity to the maxillary sinuses (upper jaw) or the inferior alveolar nerve (lower jaw). Second, and mechanically important, it increases the anterior-posterior spread — the distance between the most forward and most rearward implant in the arch. Greater A-P spread means lower bending moments on the prosthesis under chewing load, which improves long-term biomechanical stability.
The clinical evidence
Multiple systematic reviews have evaluated the evidence base for the All-on-4 concept. Key findings:
- A systematic review published in the European Journal of Oral Implantology (Malo et al., 2017, PMC5347302) reported cumulative implant survival rates of 98.8% for mandibular (lower jaw) implants and 95–97% for maxillary (upper jaw) implants over follow-up periods of up to 10 years.
- Reported mean marginal bone loss (bone resorption around the implant neck) was 1.3 ± 0.4 mm at 36 months — within the clinically accepted range for implant success.
- The same systematic review found no statistically significant difference in outcomes between tilted (angled) and axially placed implants, confirming that the angled posterior placement does not compromise survival or bone maintenance.
- Another systematic review (Del Fabbro et al., 2012) reported an implant survival rate of 98% with up to 5 years of follow-up for All-on-4 cases.
Does All-on-4 eliminate bone grafting?
In most cases, yes — and this is one of the primary clinical advantages of the technique over conventional full-arch rehabilitation. Because the posterior implants are tilted to use the better-quality anterior bone, bone grafting of the posterior ridges is not required for most patients.
However, if there is severe atrophy of the anterior bone as well, or if the patient's bone density is insufficient to achieve primary stability (the immediate firmness needed for the implant to be loaded), bone grafting or a modified approach may still be necessary. This is assessed using CBCT imaging at the consultation.
All-on-4 vs All-on-6: what is the difference?
All-on-6 uses six implants — the same two anterior vertical implants plus four posterior implants — to support the full-arch prosthesis. The additional implants change the biomechanics:
All-on-4
- 4 implants per arch
- 2 tilted (up to 45°) posterior implants
- Better suited when bone volume is limited anteriorly
- Tilting maximises A-P spread with fewer implants
- Lower cost per arch
- Higher per-implant load — more critical placement precision
All-on-6
- 6 implants per arch
- More upright implant placement is possible
- Better suited when bone quality and volume is good
- Lower stress per implant — load distributed across 6 points
- May allow a longer prosthesis with fewer cantilever extensions
- Higher cost per arch
The choice between All-on-4 and All-on-6 is made after CBCT imaging and clinical assessment. It is not a question of one being superior to the other in absolute terms — it is a question of which is more appropriate for a specific patient's anatomy. Patients with good bone volume may do better with All-on-6 because the additional implants reduce per-implant stress. Patients with significant posterior bone loss may do better with All-on-4 because the tilted approach avoids the need to graft before proceeding.
Who is a suitable candidate?
All-on-4 and All-on-6 are typically considered for:
- Patients who have lost all or most teeth on an upper or lower arch
- Patients wearing a complete removable denture who want a permanent, fixed alternative
- Patients who have been told they do not have enough bone for conventional implants
- Patients with multiple failing teeth facing full extraction
Key contraindications to assess at consultation include heavy smoking (significantly increases implant failure risk), uncontrolled systemic conditions such as uncontrolled diabetes, and active periodontal disease. These are evaluated at the initial CBCT consultation.
What the procedure involves
1. CBCT consultation and planning
The 3D CBCT scan maps the available bone in three dimensions. The implant positions, angles, and lengths are planned digitally before any surgery, allowing the surgeon to confirm that all four (or six) implants will achieve adequate bone engagement.
2. Extraction and immediate implant placement
Any remaining failing teeth are extracted. The four (or six) implants are then placed in the same surgical session under local anaesthesia. In suitable cases — when the implants achieve high primary stability — a fixed temporary prosthesis can be fitted on the same day. This is what the phrase "teeth in a day" refers to, though not every patient is clinically appropriate for immediate loading.
3. Osseointegration
Over the following 3–6 months, the implants fuse with the jawbone through osseointegration — the same biological process as in single-tooth implants. The temporary prosthesis is worn during this period with dietary restrictions (soft foods only) to protect the healing implants from excessive load.
4. Final prosthesis fitting
Once osseointegration is confirmed, the definitive prosthesis — typically a full-arch zirconia or acrylic-on-titanium bridge — is fabricated and fitted. This is the permanent, non-removable restoration.
Cost in Malaysia
| Treatment | Estimated cost per arch (private clinic, KL/Selangor) |
|---|---|
| All-on-4 (4 implants, full arch) | RM 40,000 – RM 60,000 |
| All-on-6 (6 implants, full arch) | RM 50,000 – RM 80,000+ |
These estimates include the implants, abutments, and final prosthesis. The implant brand, prosthesis material (acrylic vs zirconia), and whether any extractions or bone grafting are required will affect the final figure. Always request an itemised written quotation that specifies what is included.
Key Takeaways
- All-on-4 was developed by Dr. Paulo Malo in 1998 and uses 4 implants — 2 vertical anteriorly, 2 tilted (up to 45°) posteriorly
- The posterior tilt maximises anterior-posterior spread and avoids sinus/nerve structures, eliminating bone grafting in most cases
- Systematic review data show cumulative implant survival of 95–99% at 5–10 years; tilted implants perform comparably to axially placed implants
- All-on-6 uses 6 implants, distributes load more widely, and is preferable when bone volume is adequate
- CBCT imaging is essential to determine whether All-on-4 or All-on-6 is more appropriate for your anatomy
- Cost in KL ranges from RM 40,000–80,000+ per arch depending on system, materials, and complexity
If you are missing most or all of your teeth and wearing a denture, or if you've been told you don't have enough bone for standard implants, an All-on-4 consultation — with a CBCT scan — is the only way to know what's genuinely possible for you. We carry out this consultation free of charge at Koo Dental Clinic in Taman Connaught, Cheras.