Removal and shaping of tooth structure constitute an important part of restorative dentistry. Dental burs with their bladed cutting heads are used for tooth structure cutting, cavity preparation, and bone cutting. During cavity preparation, the principal applications of dental burs specifically diamond burs are penetration, extension, excavation, and refinement for the placement of the chosen restorative material. Diamond burs can be classified into different shapes with each shape employed for specific purpose in dental treatments.
Rounded or spherical shaped diamond burs are used for initial tooth entry or penetration, extension of the preparation, establishing retention features within the preparation and complete removal of hard carious lesions. Inverted cone and pear-shaped diamond burs are helpful in the provision of undercuts in tooth preparation. Normal length pear shaped burs are used for class I tooth preparation for gold foil whereas long length burs are best for amalgam cavity preparations. Straight fissure burs are also helpful in cavity preparation for amalgam fillings. Tapered fissured shapes in diamond burs are used for indirect restorations such as inlays and onlays. The end cutting diamonds are perform preparations apically without axial reduction.