Today we share a dental case where a long zirconia bridge would break. Let’s find reasons and solutions.

1. A lower model not ideal for a long zirconia bridge

dental model not good for zirconia bridge

Let’s look at the lower model. #35-37 and #45-47 are missing. Our doctor tries to make one long zirconia bridge #38-47, but we do not think it is a good idea: it is fine for #35-37, because #38 is a natural tooth that could act as a good supporting point.

Stone models

A zirconia bridge from #38 to #47 will break at the connector between #44 and #45, while there is still breakage risk, if it is a zirconia bridge from #38 to #46

However, #45-47 are missing. If we make a long zirconia bridge #38-47, then #45-47 could break easily. The principle is that there is no distal support for #45-47. When the biting force is too strong on #45-47, the other side (#35-38) could rock. Or #45-47 would break over time. We can say that even a 14 units zirconia bridge from #38 to #46 is dangerous.

In this case, a long PFM bridge #38-46 will not function well either. The strong chewing force of the back teeth could result in porcelain crack over time. If so, dentists have to remake the whole bridge.

2.  Zirconia is hard but not flexible

Please don’t tell me that you have long zirconia bridges in such conditions, and they are all good. It depends on how the patients care for their long bridges. We are talking about the much higher chances of remakes (remake rates), not just a few exceptions.

Zirconia is very strong and hard (can be 1200 Mpa), but not flexible at all. When the strong biting force focuses on several cantilevers without any support, the connecting point would break easily, even after we strengthen the lingual connectors.

3. A dental case suitable for a long zirconia bridge

stone model for long zirconia bridge

stone model for long zirconia bridge

Now let’s look at another lower model. #35-37 and #45-46 are missing. With this model, we can make a long zirconia bridge #38-47, because #38 and #47 are natural teeth. There are enough supporting abutments for the missing teeth.

4. Dental solutions

We strongly suggest to make a shorter zirconia bridge from #38 to #45. With only one cantilever #45, it is very safe. This can help doctors and patients to avoid trouble in the future.

Preciline dental attachments

Preciline dental attachments

Another solution is to make combination dental work. It is a good idea to use Ceka-Preciline dental attachments. Therefore, this case consists of a PFM bridge for #34-44, two Ceka-Preciline dental attachments, and a metal framework with acrylic partial.