If you're considering full-arch teeth replacement, you've likely encountered the term "All-on-4" during your research. This dental implant technique transformed the way dentists approached full-mouth restoration. In this comprehensive guide, we'll explore everything you need to know about All-on-4 dental implants, from their history to how they compare with alternative solutions.
The History of the All-on-4 Procedure
The All-on-4 concept didn't appear overnight; it represents decades of research and innovation in dental implantology. In the 1950s, Professor Per-Ingvar Brånemark, a Swedish physician, accidentally discovered that titanium could successfully integrate with bone tissue – a process he later termed "osseointegration." This discovery laid the foundation for modern dental implants.
However, it wasn't until the 1990s that Portuguese dentist Paulo Malo, in collaboration with Nobel Biocare, developed and pioneered the All-on-4 technique. Malo recognized that by strategically placing four implants at specific angles, they could support an entire arch of teeth without requiring extensive bone grafting procedures that were common with traditional implant methods.
The technique was first implemented in 1998, and after years of clinical research, it was officially introduced to the dental community in 2003. Since then, hundreds of thousands of patients worldwide have benefited from this approach to full-arch rehabilitation.
While this procedure was originally created by Nobel-Biocare, many dentists have since used the same technique and varied the number of implants used in the procedure. For this reason, it is often referred to as All-on-X, with ‘X’ representing the number of implants being placed.
What is the All-on-4?
All-on-4 is a full-arch prosthetic system designed to replace an entire upper or lower set of teeth. The system involves two anterior implants placed vertically in the front of the jaw and two posterior implants inserted at an angle, typically between 30 and 45 degrees. This angulated placement maximizes contact with available bone and provides increased stability, particularly in patients with reduced jawbone density.
The prosthetic typically consists of a hybrid denture, constructed from materials like acrylic, porcelain, or zirconia. This prosthesis is supported by the four implants, distributing biting forces evenly across the jaw and reducing stress on individual implants. This treatment process is designed to accomplish a couple key goals:
Reduce the Cost of Full-Arch Rehabilitation
The biggest cost in restorative dentistry is placing implants. By reducing the amount of implants needed to restore a full-set of teeth, the dentist can reduce the total cost to the patient. The All-on-4 uses only four implants to restore an arch of teeth, thereby reducing the total potential cost of the procedure.
Simplify the Surgical and Restorative Process
That bone and tissue in the mouth have natural contours to them like a mountain range. To reduce the time in surgery and simplify the process for the dentist, the procedure removes the contours of the bone and reduces it behind the lip line. This creates a flat surface for the prosthesis to attach to and removes any need for bone-saving methods like bone grafting.
Overview of the All-on-4 Procedure
Like most dental surgeries, the bulk of the work is done in a day, but follow up appointments are required after the implants have healed. This means that the full treatment timeline typically takes between 4-6 months.
Day of Surgery
Anesthesia & Sedation: The patient receives the desired level of anesthesia to be comfortable during the procedure.
Tooth Extractions: Any remaining teeth are extracted. For a typical All-on-4, even healthy teeth must be removed in order to receive the prosthesis.
Bone Preparation: The dentist prepares the upper and lower jawbone for the All-on-4 prosthetic. This typically involves an alveoloplasty procedure in which the gums are flapped and then the bone is shaved down to a flat surface. This makes it easier for the dentist to predictably install the prosthetic. The dentist will also ensure that enough bone is removed so that the transition to the prosthetic will be hidden behind the lips when smiling.
Patient bone after alveoloplasty (left) and bone removed (right) Implant Placement: In a typical All-on-4, four implants will be placed in the upper jaw and four in the lower. In most cases, two anterior implants are positioned vertically in the front of the arch and two posterior implants are placed at an angle near the back. The back implants are placed in this way to maximize contact with available bone and avoid critical structures like sinuses or nerves.
Temporary Prosthesis Placement: A temporary full-arch prosthesis is secured onto the implants after they are placed. This method is called immediate loading and is why many dentists advertise “teeth in a day” even though the full process takes closer to 6 months. The prosthetic is fixed (not removable by the patient) and is usually made of an acrylic material that will be replaced later with a stronger material.
Wake from Sedation: The patient is then awakened from sedation. Patients may take a few hours for the effects of sedation to wear off and are most often accompanied by a loved one and taken home to rest.
After Surgery
The surgery typically takes 2–3 hours per arch. Patients leave the clinic with a functional set of teeth and can eat liquid or soft foods by the evening. They then enter their healing period while the implants will undergo a process called osseointegration in which the titanium posts fuse to the surrounding jawbone. This process takes between 3-6 months. During this time, patients are typically on a soft food diet. They will also have follow-up appointments to ensure they are healing properly.
Final All-on-4 Prosthetic
Once osseointegration is complete, the temporary prosthetic can be replaced with the permanent one. Patients will usually receive more scans of their mouth so the final prosthetic can be custom fit. Final All-on-4 prosthetics are typically made of porcelain or zirconia, and some may have different materials for the tooth and artificial gum portion of the restoration. Some All-on-4 prosthetics include a titanium bar to help protect the prosthetic from breaking.
Key Benefits of All-on-4
The All-on-4 technique offers numerous advantages that have made it popular among patients and dental professionals:
Immediate Benefits
Patients can have their damaged teeth removed, implants placed, and temporary teeth installed in a single day. This provides an instant esthetic improvement which can improve many areas of a patient’s life.
Enhanced Quality of Life
The patient’s ability to eat a wider variety of foods can be restored after healing, usually at the 4-month mark post-surgery. Many patients with oral complications suffer from dietary restrictions. An improved diet has many benefits that can improve their overall health and quality of life. For a patient who had been in a denture, they will also notice improved sensory feedback and taste without their palette being covered by the denture.
Daily maintenance and care of teeth is also commonly improved. Standard dentures require adhesives, soaking the appliance overnight, and thorough cleaning. All-on-4 maintenance is generally less intensive, requiring regular brushing and flossing. Speech is also likely to improve for a patient that has had major oral problems or been in a denture.
Oral Health Improvements
For a patient that qualifies for All-on-4, they’re likely experiencing gum disease, bone loss, and pain. All-on-4 treatment removes diseased teeth, instantly removing pain and infection. The addition of implants can also help stabilize bone and protect it from future deterioration. For a patient who has suffered serious bone loss, their facial structure will be improved, adding beauty and youth to their looks and reducing pain and discomfort.
Drawbacks of All-on-4
While All-on-4 dental implants offer numerous benefits, it's important to consider potential drawbacks:
Financial Considerations
The All-on-4 will have a higher upfront cost than other options like dentures or snap-in dentures. As of 2025, the average cost in the U.S. is estimated to be somewhere between $30,000-$60,000 for a full All-on-4 restoration. This number is higher if more implants are recommended. These costs are rarely covered by insurance. In addition, the ongoing maintenance costs of All-on-4 can be quite high. Annual removal and cleanings along with screw replacements can cost $500-1,000 per year.
Treatment Risks
The biggest critique of the All-on-4 process is the irreversible bone removal at the time of surgery. Destroying the bone reduces the options available to the patient in the future if the implants were to fail. This methodology is seen by some dentists as unnecessary and not in the best interest of the majority of patients.
In addition, some patients may have what doctors refer to as a "gummy smile," meaning, they show a lot of gums one they smile. In order to hide the prosthesis, a significant amount of bone must be removed. In some cases, a dentist may not remove enough bone, causing the All-on-4 transition line to be visible when smiling, giving an unesthetic and uncomfortable result.
Another concern is the risk of breaks and fractures of the All-on-4 prosthesis. The large, U-shaped restoration is more prone to chipping and breaking than individual bridges and crowns. If any part of the restoration is damaged, the entire prosthesis must be replaced. This can cost the patient over $5,000 in added expenses.
Adjustment Period
Many patients report a difficult adjustment period after getting their All-on-4 restoration. The bulky prosthetic can feel unnatural and require the person to adapt their speaking and eating. In addition, patients don’t feel the same physical responses when chewing, which can feel unnatural and contribute to over exertion on biting forces. A percentage of patients never adapt to the All-on-4 and decide to switch to another treatment option such as the 3 on 6™.
Maintenance Requirements
Overall, the All-on-4 is more difficult to clean at home than regular teeth. Food traps and hard to reach areas greatly increase the chances of bacteria growth. Untreated bacteria can lead to bad breath, bad taste in the mouth, and implant failure. Regular professional cleanings are recommended which include the removal prosthesis. In addition, full arch prosthetics like the All-on-4 are known to have chips or fractures which can require expensive fixes and replacements.
Not Suitable for Everyone
While the All-on-4 can sometimes be the most cost-effective option for permanent teeth replacement, it may not be the best choice for many people. Growing concerns about the bone reduction required to fit the prosthesis in the mouth have caused a growing number of dentists to speak out about their concerns and the potential risks that patients may not be aware of. Many of these dentists support newer treatment modalities such as the 3 on 6™. If a patient has had extreme bone loss, they may not require any bone reduction, and in those cases the All-on-4 may be the best option.
Long-Term Viability
Little is known about the long-term outcomes of All-on-4 on bone health. A 2011 study painted a glowing picture of All-on-4 longevity, but many criticize the data as it was authored by Paulo Malo, creator of the All-on-4 treatment. Today, the majority of dentists tell their patients to expect their All-on-4 smile to last about 10 years.
Dr. Tomas Linkevicius has presented research that demonstrates that the likelihood of a fracture in a crown is 1.3% and that the number increases to 6.7% for a fixed-partial denture (like the All-on-4). In addition, 38.1% of fixed metal-ceramic restorations (like All-on-4) experienced chipping damage within a 5-year period.
Conversely, research conducted by Smile Systems over a 6-year period found that for 3 on 6™ patients with segmented dental bridges, only 3 bridge fractures occurred out of over 5,000 bridges placed, a fracture rate of .0006%. This research would demonstrate that fractures and chips are far more common in full-arch prosthetics like the the All-on-4 than in single crown and bridge restorations.
Conclusion
All-on-4 dental implants are a popular choice for patients in need of smile restoration. They offer a reliable and efficient solution for full-arch tooth replacement. While the procedure requires careful consideration of both benefits and drawbacks, its success rate and drastic change in a patient’s life make it an attractive option for many people seeking to restore their smile and oral function.
The decision to proceed with All-on-4 implants should be made after thorough consideration of all the available options. A qualified dental professional should assess your specific situation and needs and inform you of all of the major treatment options available. Patients should exercise caution as many dentists will recommend the treatment option they know best while ignoring newer alternatives available.
While the initial investment may be significant, the long-term benefits of improved oral health, function, and quality of life make it a worthwhile consideration for those seeking a permanent solution to tooth loss. Successful dental outcomes will always depend on proper surgical execution, prosthetic restoration, and patient commitment to healthy living and proper maintenance. With appropriate care and regular dental check-ups, All-on-4 dental implants can provide a great solution that allows patients to smile with confidence for years to come.
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