What is the best bur to cut through monolithic & layered zirconia crowns?
The choice of dental bur for cutting through a zirconia crown may depend on various factors, including the type of dental handpiece you are using, the specific characteristics of the zirconia material, and your personal preferences.
Diamond burs are often used for cutting through hard materials like zirconia. Diamond burs are known for their hardness and durability, making them suitable for working on materials with high levels of hardness. Additionally, water spray during the cutting process can help cool the bur and prevent overheating.
Specifically designed zirconia-cutting diamond instruments have been marketed with the claim that they avoid excessive heat and stress generation. Conversely, others have reported no significant difference in cutting efficiency between the dedicated zirconia instruments and conventional diamond instruments within the first 5 minutes of cutting.
Cutting zirconia is notoriously difficult because it has a very high strength, toughness and wear resistance. It is perhaps counter intuitive but what bur manufacturers have come to learn is that very fine grit burs are actually the most efficient burs for removing zirconia. Coarse grit burs tend to just immediately burn and lose efficiency immediately.
To ensure maximum life Frank Dental offer the D.Z881.012.C.FG (Yellow/Orange band) which contains a double layer of extra fine diamonds which is specific for cutting through a monolithic Zirconia Crown with ease.
What is the best bur to cut through a layered Zirconia Crown (Emax/Zirconia)?
Please note that if the zirconia crown you are removing has a layer of veneering porcelain then this is better removed initially with a coarse grit diamond bur then change to an extra fine grit diamond bur.
Frank Dental has manufactured a special 2 in 1 tool D.Z880.012.GC.FG (Green/Orange band) which contains 2 grits of diamond particles. The top layer consists of a coarse grit natural diamond to cut through the top porcelain layer, once the coarse grit diamonds come in to contact with the Zirconia framework they start to disperse resulting in the extra fine layer diamond grit appearing to continue to cut through the remaining Zirconia restoration.
It is also important to use a good quality handpiece which has been regularly maintained, ideally a 1:5 speed increasing handpiece. The optimal speed for the burs to be used is 160,000 RPM. The other important factor is to ensure minimal pressure is applied to the bur when being used, excess pressure will result the diamonds burning from the head of the bur whilst generating sparks, if this happens reduce the pressure applied.
