All on 4 framework options
All on x and All on 4 framework options
All on 4 framework or all on x framework choices are no longer just a choice between what kind of metal. Advances in material science now allow the use of many new materials and manufacturing techniques are also changing.
All on x or all on 4 framework options
All on x or all on 4 framework options can be broken into three general categories. The first is metal and has been around the longest, the second is porcelain, the final consists of several materials that I am grouping together.
#1 Metal all on 4 or all on x frameworks
- Gold alloy or other noble metal alloy
- Titanium
- Chromium Cobalt
Advantages of metal all on 4 framework
- Long history or use in dentistry and many dental labs and dentists are familiar with the product.
- Very strong and difficult to break when made properly.
- If the all on 4 metal framework breaks, we can be laser weld it back together. This is not easy and maybe impossible if there is porcelain on the metal.
Disadvantages of metal all on 4 frameworks
- Metal costs more than other frames and the noble metal frameworks in particular are far to expensive to be practical.
- Heavy and if need to have a large frame the individual may notice the weight.
#2 Porcelain all on x framework
- Zirconia
Advantages of zirconia all on 4 framework
- It is white and is very strong.
- Zirconia is a very tissue friendly material.
- Curiel-Aguilera JPD 2023 shows zirconia has less plaque accumulation than titanium.
- If want strong teeth that are hard to break and do not wear down then you can make the framework and teeth one piece and this cuts way down on cost.
Disadvantages of a zirconia all on x framework
- Technique sensitive so not all labs or doctors will know how to work well with it. This is mostly out of the doctors hands.
- Need to ensure using high quality zirconia
- If the lab does not treat the zirconia right or if they use an inferior zirconia product, zirconia frameworks can break and there is NO fixing it.

These images show what the white zirconia framework looks like before and after porcelain is baked on top of it. Ignore the two yellow blobs on top of the zirconia, that is composite we use to verify the bite.
#3 Polymer, resin, fiberglass all on 4 framework
Of these frames there are some advantages and disadvantages of each one. For instance, Trilor and Trinia do not hold up well when we expose them so they must have composite covering them. We can expose Pekkton to the oral environment. We have an entire post that discusses the fiber reinforced framework.
- Pekkton is the strongest material in the high performance polymer family.
- Trilor is a multi-directional glass fiber reinforced epoxy resin
- Trinia seems to be the same or very similar to Trilor.
- Juvora is a PEEK product and I feel the other polymer materials make more sense for frameworks.
Advantages of the polymer all on 4 framework
- They easy to mill and furthermore the milling pucks are cheaper to buy.
- All the polymers and resins are lightweight in comparison to the other categories and therefore are easy for patients to adapt to.
- They act as a shock absorber since they have some give. This is the best attribute of the material as it likely will help take some of the stress of off other important parts of the system.
- The fit is better than zirconia or titanium according to Yilmaz 2018 JPD
Disadvantages of the polymer all on x frameworks
- Can not be repaired if breaks, however, we can re-mill them cheaply.
- New product so not many labs will know the material well and there is not a lot or research behind it.
- Some must have a composite, acrylic, or porcelain coating to stop fraying, notably Trilor and Trinia.
How do we make the different all on 4 framework options?
Today nearly everyone is milling their implant frameworks but there are other ways to achieve an accurate high quality all on x framework.
Milling the all on x framework
The most common method of making all on x frameworks. We can mill a commercially pure block of material to very precise specifications. We can mill every material available today and for many materials the only way to make them is to mill them. Materials typically come in a block that we call a puck because it looks like a hockey puck. The design for the framework is made on the computer or we scan the design into the computer. This CAD/CAM technology drastically increases accuracy and decreases labor costs. s intrinsically homogeneous
3D printing the all on 4 framework
I am sure there are some places 3D printing all on 4 frameworks but it is not common. This additive manufacturing technology could replace the milling in popularity at some point but for several reasons is just not there yet. If using a metal it is currently easier to print resin or wax and then use lost wax according to Dawood.
Lost wax technique for an implant framework.
Traditionally metal was the only option and we made it the same way we made everything else in metal for dentistry. We hand create or print the framework in wax or resin and use the lost wax technique to cast it into metal. This technique can create air pockets with inconsistencies in the frame and shrinkage upon cooling. Furthermore, since frameworks are large there is more shrinkage. The larger it is the more error is built in due to cooling. The cooling of the metal results in shrinkage and misfits, which for small things like crowns is acceptable but for large volume fall on x frameworks create serious misfits. To do this right often requires sectioning and laser welding the parts back together on the model. This is labor intensive, expensive due to metal costs, and inaccurate, therefore it is rarely done today.
What is our preference for an all on x framework?
Finally, my ideal all on x prosthesis is titanium or CrCo framework with some sort of porcelain teeth on one arch and nanocomposite teeth on the other arch. This allows the teeth to be the shock absorber instead of the framework or the implants. I have instances where I prefer the polymer frameworks such as cases with little or no cantilevers, but since the products are new I worry about long term durability. Since you have an interest in framework choices you likely have an interest in tooth selection too, therefore our all on 4 teeth selection page may be of interest.
I am getting all my upper teeth pulled and have opted to have the All on Four procedure. ( eventually will have both the upper and lower done this way).
My dentist will be doing some bone grafts first … He doesn’t explain things well, and when I asked him how the teeth are joined together, all he said is they are attached to metal like a horseshoe… Is that the only way that most dentists do this? Seems so odd, and all that metal resting on my gums all the time has me
a little concerned. Should I be? And when I asked him how natural the teeth will look, all he did is remark that making them look real good is a very expensive job for the lab… which led me to think that unless you want to pay considerably more~ the appliance will look like “false teeth”… 🙁
I need some reassurance here~ this is a lot of money, and Im feeling very discouraged, anxious, and uncertain now…
Any comments would be appreciated. Thank you
It can be an overwhelmingly process and it’s unlikely you will be able to understand even most of what is happening. What your dentist has told you is accurate. It is common to leave the metal exposed against the gums. This is what it can look like if you want a very natural look but yes that does cost considerably more. Many of the newer acrylic teeth look really nice and cost way less so unless you are paying around $30,000 plus per arch then you won’t get the highest end teeth. I will add however that very few non dentist humans can discern the acrylic teeth from the high end cosmetic ceramic ones.
Rose, I was looking online for Anyone who was going thru a similiar experience as we are and saw your post..My Gf is in Exactly the same boat as you and it has me very concerned..She has had all the upper teeth pulled and has been Without Any teeth in her upper mouth for what is now 8 months while we wait to get a zirconia “hybrid” upper ..We were quoted 18,000 for the implants and bridge… its an all on 4..My concern is the pictures he showed us of what was going in there looked Not at all attractive ,nor was it anything like the nice all on 4 zirconia i see all over the web if u search.Instead, he showed an image of a dark titanium metal horseshoe that he said would have the zirconia on top of it..I said will the metal part be visible? wont it be covered so that the metal is not exposed to the gum area? He said, no, the metal will be on the underside but you wont see it cuz its hidden by the gumline..when i asked about metal on the gum area ,he said we leave a small gap for cleaning so it wont touch the gums..This setup Doesnt look like anything i see for zirconia all on 4 when looking online..the closest image i could find was some horror made in a mexico dental lab.
I am worried for her that she get a quality item and not some poorly designed teeth that will cause her troubles..she is more trusting than I and gets mad at me for bringing it up..The dentist now wants to “upgrade “ the teeth to a horseshoe bar with “replaceable” individual zirconia teeth.He mentioned this becuz he said the one piece zirconia has snapped off the bar and even showed me a pic of this.. scarey!
so the upgrade is now 23,000 and Still being designed on a metal horseshoe that will be next to the gums…I said same thing as you: is this Really how its done? he said dont go by what you see online, thats not accurate of how we do things.. she is likely going ahead with it…I have concerns though…. best of luck , you are not alone in this…My I ask how much is he charging you for ur all on 4 and is it acrylic or zirconium?
Also, is he going to give you an attached temporary while the implants are healing..? Our dentist only offered a cheap plastic denture and some polident adhesive! she couldnt stand wearing those so she had gone with No teeth this whole time..
Paul it is common to leave the metal exposed against the tissue and you will not see it. With individual zirconia teeth the look can be whatever you want it to be. This one has metal on the underside exposed to the tissue and one would be hard pressed to make something look more natural.