Dental Burs Classification and Features

Study Notes

Carbide vs. Diamond: Carbide burs are made of tungsten carbide with a set number of blades that slice away tooth structure. Diamond burs are constructed with stainless steel bonded with diamond particles, which grind away hard tissue.
Bur Features: Burs have various shapes, head angles, blade geometry, grit, and cutting diameters.
Bur Identification: Carbide burs are identified by a numerical code (e.g., 330, 557). Diamond burs are identified by a numerical code on their packaging.
Shape: The three numbers before the period in the code indicate the bur's shape and taper.
Grit: Grit influences how much material is removed, a finer grit is used for finishing and a coarser grit is used for rough cuts.
Cutting Diameter: The last numbers in the code refer to the bur's maximum cutting diameter in millimeters (mm).
Cutting Length: The two-digit number between the periods in the code denotes the bur's length.
Bur Selection: The appropriate bur selection depends on the desired application, for example, a shoulder bur (flat end taper) is commonly used for creating a shoulder margin. Barrel burs are used for reducing occlusal surfaces on molars, wheel burs for incisal edges, and egg burs for reducing lingual surfaces on anteriors.

Lab Putty Properties: Lab putty is a material used to create custom reduction matrices which are used for facilitating even reduction of tooth structure.
Mixing, Placement, Sectioning, and Usage: Lab putty is mixed according to manufacturer's instructions, placed around the tooth, allowed to set, and then sectioned to create a mold that guides the preparation.