Full arch fixed implant bridges AKA All on 4 are taking the dental world by storm!!! These “bridges” are usually supported by 4, 6 or 8 dental implants and are fabricated from materials such as Acrylic fused to Titanium, Monolithic Zirconia, and Porcelain stacked to a cobalt-chromium frame
5 to 10 years ago patients didn’t know the All on 4 even existed. Today patients are requesting this treatment specifically, but is it the best option?
What are All on 4 Dental Implants?
All on 4 dental implants are a full set of implants designed to replace your entire upper or lower set of teeth. They act as a more permanent and stable solution than just your regular typical dentures. Prior to this procedure, dentist would insert implants to replace each lost tooth individually, now with the All on 4 we can secure a full arch denture creating a seamless look across the entire mouth, saving the patient lots of money and time.
All on 4, 6, & 8 are the three dental implant options available each of which serves to completely reconstruct a patient’s smile. 4, 6, & 8 represent the number of implants that will be inserted into the jawbone. Determining how many implants is right for your case is done using cutting edge technology to obtain the most accurate and precise reading of your facial and bone structure. The quality and quantity of bone structure is studied and determined by your dentist through 3D imaging.
By inserting 4-8 implants your dentist can now use these implants for structure and stability and create a prosthesis that’s more stable and permanent.
There are three types of implants available for your dentist to choose from after studying and determining how much anchorage is needed for optimal structure and to achieve the best results in recreating your smile. Standard Endosteal, Zygoma and Pterygoid implants are commonly used in the All on 4 procedure.
- Standard Endosteal implants typically made of titanium, Endosteal implants are the most standard type of dental implant that are inserted into the jawbone as an artificial root to hold a replacement tooth. The bone area must be sufficient to support the implants in height, width, and length. Endosteal implants can be either blade or root form. The type of Endosteal implant selected is based on the amount of bone, the quality of bone, and the patient’s expectations of how the final restoration will look, feel and function.
- Zygoma implants take the anchorage from the Zygomatic bone (cheek bone). The Zygomatic bone is denser in quality and more cortical in nature than the posterior maxillary bone. Because of the sturdy anchorage achievable in the dense bone of the Zygomatic region, and the wide stress distribution achieved on these tilted implants, a prosthetic can often be immediately placed at the time of surgery. Zygomatic implants can be used in patients who do not have any teeth in the upper jaw, patients who have heavily broken down teeth or very mobile teeth due to diseases such as generalized aggressive periodontitis.
- Pterygoid implants are integrated into the pterygoid process of the sphenoid bone, a bone that forms part of the base of the skull, reaching up to 55mm in length they are placed in angled positions. Unlike other implants, Pterygoid implants anchor in cortical bone, allowing a better primary stabilization which is known to be a critical factor for long term success. From a prosthetic point of view it can minimize the time to rehabilitation and bypass the need of a distal cantilever and also makes it possible to perform, if the patient meets the indication criteria, an immediate prosthetic load. Pterygoid implants present an alternative option to use residual bone for implant anchorage and to overcome the need for augmentation procedures.
Zygomatic and Pterygoid implants are two types of “long” implants used when the patient insufficient quantity or quality of bone to anchor implants of regular dimensions. In these cases bones of greater hardness are used such as those in the area of the cheek bones to anchor the implants since they always maintain their hardness and density. The main characteristics of these implants are that they are placed in two bones that are never reabsorbed: The zygomatic, in the case of Zygoma implants and the Pterygoid, in the case of Pterygoid implants. So they can be used even in the most severe atrophies of the maxillary bone. In addition, Zygomatic and Pterygoid implants are also special for their length, much longer than conventional implants. Thus Zygomatics have a length of 30 to 55mm and Pterygoid of 15 to 22mm, a length designed to ensure correct anchorage in the bone.
Patients with significant amounts of bone loss or a narrower, less sustainable jawbone will definitely benefit greater with the insertion of 8 implants, giving the patient an increased amount of stability & an all-around better fitting prosthesis. When a healthy, substantial jawbone is present, fewer implants can be used to achieve the same or better results. So while performing the traditional All on 4 is perfect for some patients, using 6 implants makes anchorage tighter and more solid and using 8 implants offers the maximum amount of stability reconstructing the mouth and filling in all missing teeth.
Bone loss is a very common side effect of tooth loss. This is because, without the roots of the teeth in place, the jaw bone slowly starts to resorb or shrink back. It is part of the reason that your once snug fitting dentures can become loose and uncomfortable, and also often lead to a prematurely aged, sagging appearance to the skin around the jowls. There are 2 ways to rebuild bone loss.
- Bone Grafting: A procedure that replaces and regenerates lost bone, and can also restore proper facial contour. Bone grafting traditionally involves removing a piece of bone from somewhere else in the patient’s body and transplanting it into the jawbone. Bone Grafting can also be obtained from a cadaver or animal source to replace missing bone structure. After this process, it may take several months for the transplanted bone to grow enough new bone to support the actual dental implant.
- Sinus Lifting: This procedure uses the contour of your face to provide a second chance at the functionality and reliability of dental implants. It involves lifting the lining of the sinus cavity and packing the space with bone or synthetic material. This procedure aims to increase the amount of bone in the posterior maxilla (upper jaw bone) typically in the area of the pre-molar & molar teeth. After a 4 month healing period your implants can be placed.
Complications and Prevention:
Implant failure is the most common complication of the all on 4. This happens in about 5% of patients. While the fail rate is relatively low it’s still cause for great concern. It usually happens when the implants do not fuse with the bone. It’s not always clear why this happens, making it frustrating for all parties involved.
Infection: There’s also a low risk of infection with dental implants. Infection can occur for a couple of different reasons; something may have become contaminated during surgery. Infection around the implant is a type of gum disease and is called Peri-Implantitis.
Some Symptoms of Peri-Implantitis are:
- Loose or wobbly teeth/implants
- Red or puffy gums around the implant
- Bad taste and/or breath
- Pain in the implant area
- Collection of pus
- Pain in the implant area
- Being able to visually see the top of the implant
- Bleeding when brushing
Prevention: Following your dentists’ instructions post-surgery will prevent a lot of the above complications, practicing good oral hygiene, keeping the implants & teeth nice and clean. You can use a Waterpik and special flosses to ensure you’re taking good care of your implants. Also we highly recommend you keep up with your 6 month checkups. Being diligent in your after care will ensure a healthy and smooth recovery.