If you’re considering All-on-Four® dental implants (or just doing some research), you probably have a few questions such as, How do they work?, Are they better than traditional implants and dentures?, How well do they hold up?, etc. As an implant dentist in NYC and an instructor at the NYU School of Dentistry, I am experienced in all implant techniques which puts me in a great position to answer your questions. So, here we go!
All-on-4® is a registered trademark of Nobel Biocare. It is an implant treatment plan designed for people who need or want to replace all of their teeth in either one or both jaws using an absolute minimum number of implants. The process enables dentists who are trained in this concept to replace the teeth with one single dental restoration or bridge, supported by just four implants.
That’s right. With All-on-Four® dental implants, ten to twelve of your upper or lower teeth can be replaced using only four implants for support. What’s more, most patients have a fully functional fixed set of “teeth” the very same day their implants are placed.
How Do All-on-Four® Dental Implants Work?
The All-on-4® technique was developed by an early implantologist named Dr. Paulo Malto in the late 1970s. It was considered an option for patients who had inadequate bone to support traditional implants to replace their back teeth. Today’s advanced bone-grafting techniques, such as sinus lifts and ridge augmentation, didn’t exist. “Necessity is oftentimes the mother of invention. “
And so, Dr. Malto conceptualized a novel treatment approach for the edentulous patient who was also lacking sufficient bone for traditional implant therapy. He placed two implants in the front part of the jaw and two additional implants placed a little further back which were angled in such a way as to allow for a more expansive fixed teeth replacement. With this method, the four implants could support as many as 10-12 teeth.
For illustrative purposes, think of the George Washington Bridge right there on the Henry Hudson Parkway with its four anchors of support: two terminal bases planted firmly on the shores of both New Jersey and New York, and two nearly mid-span pillars originating from the bedrock of the river bed and soaring to the sky above. These four anchors can be thought of as All-on-Four® implants, and the bridge’s steelwork and roadway can be thought of as the replacement teeth. (Both structures are marvels of engineering.)
With the continued advancement of dental technology such as dental CT scans, advanced imaging, computer-generated surgical guides and the accuracy of CAD/CAM design and milling techniques, implant therapies such as All-on-Four® have not only improved but are now mainstream. Over time, more iterations of the All-on-Four® dental implants concept have evolved with names such as All-On-Five, All-On-Six, Teeth-In-A-Day, and Teeth-Tomorrow.
All-on-Four® Dental Implants – Pros & Cons
The All-on-Four® dental implants treatment concept is popular in the United States, and it’s no wonder. It has a lot going for it compared to traditional implant treatments, including…
- Less Surgery: Only four implants need to be placed, and bone grafting procedures such as sinus lifts are often not required.
- More Economical: Because only four implants are being placed, the cost of the surgery, as well as that of the final restoration, is less.
- Not As Time-Consuming: The process requires fewer hours in the dentist’s chair because advanced surgical procedures are often unnecessary. Plus, less time and fewer visits are required to fabricate the final restoration.
- You Walk Out With Teeth That You Don’t Have To Remove!: The same day your implants are placed and often the same day your remaining teeth are removed – you’re done. (Well, not quite. The “teeth” you walk out with on the day of implant placement are temporary (provisional) restorations. The final restorations are not placed until the implants have had time to heal/integrate into the bone, generally about 4-6 months.)
If you’re leaning toward All-on-Four® dental implants, you need to know that they are not for everyone. There are two things you need to know:
If you’ve ever seen a denture-wearer when their denture is not in place, their face often has a “collapsed” look because the gum and bone that once supported their natural teeth are missing. The pink acrylic part of their denture is what provides that support. An All-on-Four® restoration often mimics a denture in the amount of lost gum, bone, and tooth structure that is being replaced; hence, it can be quite bulky, especially when proper lip support is needed.
Remember my George Washington Bridge analogy? An All-on-Four® restoration (the teeth and gums being the roadway) is built on a superstructure of zirconium that’s colored to look like your natural gum and teeth (the steel, concrete, and cables of the suspension bridge). It is then screwed into special abutments (the anchors) affixed to your four implants (the foundation). Because only four implants are supporting such a large restoration (the bridge) with up to twelve teeth and associated “gum and bone,” a large expanse of your mouth is covered with a structure that must be thick enough to provide sufficient dimensional stability and have the strength to withstand significant biting forces.
In addition, some space must be left between your natural gum and your restoration to make it easy to clean. An All-on-Four® restoration sits on its underlying implants like a dock sits on its woodpiles. Of course, the space is measured in millimeters, not feet. Food will collect and accumulate underneath, and diligent home care must be exercised routinely. Suppose a significant amount of natural gum tissue is missing. In that case, your dentist may also need to extend the restoration over your remaining gum, making good homecare practices even more important – and perhaps even more challenging. A Waterpik® or other irrigating device is essential.
If Just One Implant Fails, There’s Trouble
Studies have indicated that dental implants have a greater than 95% success rate as long as the diagnosis is thorough and thoughtful, the surgical techniques carefully planned and executed, well-fabricated restorations, and appropriate follow-up care. But in the real world, some implants invariably fail.
In my roles as an implant dentist in NYC and an implant instructor at the NYU School of Dentistry, I make it my business to properly address the clinical and biomechanical demands that are placed on my patients’ teeth and their implants. When I design implant treatments that use five or six implants, the entire restoration lest not be doomed if a single implant fails because of the support offered by the remaining ones.
But it’s not the case with All-on-Four® dental implants. Four implants must support the functional load of an entire arch of “teeth.” If you bite, chew or grind with stronger than average force, your implants can be overloaded, and the possibility of implant failure is higher. The entire restoration must be removed, additional implants placed, and a new restoration made. It‘s costly in time and money.
Ask Your Dentist These Two Important Questions Before You Say “Yes”
Of course, it’s your dentist’s responsibility to determine whether All-on-Four® is a viable treatment option for you. Still, it’s your responsibility to ask the right questions and to do your due diligence. What will your teeth look like? How different will an All-on-Four® restoration be when compared to natural teeth? Conventional crowns and bridgework? More conventional implant dentistry?
Before you embark on an All-on-Four® dental implants treatment course, there are many things to consider. So, if you aren’t 100% sure your dentist is being thorough enough in their assessment of your mouth, please get a second opinion before you say, “Yes.”
Do you have questions about All-on-Four® dental implants? Please leave your comment in the area below.
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* Dental restorations are fillings, crowns, implants, bridges and dentures.