Sintered Diamond Burs and Their Effect on Tooth Surface Properties
A diamond bur is a rotary cutting instrument with bladed diamond points and can be used for tooth preparations, caries excavation, coronoplasty or the finishing of restorations. They are often available with a friction grip or RA latch type shank. Diamond burs are superior to other rotary cutting instruments in terms of their efficiency, durability and longevity due to the presence of high concentration of quality diamond grit.
The diamond grit is embedded into a metal matrix throughout the entire head of the sintered diamond bur which makes these burs much more durable than coated or plated lapidary burs, allowing them to stay sharp longer and provide consistent cutting performance over an extended lifetime. The diamonds are also bonded to the shaft with an aluminium oxide which prevents contamination of the workpiece and ensures that each bur delivers a fresh layer of diamond each time it is used.
A wide range of grit sizes are available to suit any cutting requirement. Diamonds in the extracoarse (black, ISO 544) and coarse grits are ideal for texturing metal alloys whereas medium grits and finer grits are more appropriate for use on ceramics and stones. Each grit size is available in various head shapes including rounded, flame, and bullet to cater for different applications.
Despite the increasing popularity of alternative cutting methods such as air abrasion and lasers, dental burs remain the preferred tool for many dentists due to their efficiency and longevity. However, new techniques are constantly being proposed to improve the performance of dental tools and reduce the amount of time patients spend under anesthesia.
This study aimed to investigate the effect of multiple use of sintered diamond burs on tooth surface properties. The alterations on the tooth surface caused by the diamond burs were assessed using stereomicroscope images and depth map presentations. The results indicated that the surface of teeth treated by a single diamond bur is significantly smoother than that of a tooth treated by two diamond and one zirconia-cutting tungsten carbide burs after repeated use.
It is recommended that the diamond bur should be changed after the preparation of five teeth at the most. This is to avoid the wear and tear of the diamond which will cause a decrease in cutting efficiency. The changing frequency of the diamond bur is influenced by several factors, such as sterilization and disinfection procedures, storage conditions, corrosion, multiple use and the hardness of the surface particles. These factors can be controlled by proper storage of the burs and regular cleaning with a silicon carbide stick which removes surface contaminants. This will extend the life of the diamond and improve its performance.