Burs and Diamonds: An Overview of the Options
Blade configuration, diamond grit, and head angling are key
Burs have come a long way since their primitive origins several millennia ago, and they serve a variety of purposes for a number of procedures. From crude beginnings as primitive cutting devices, they have evolved into modern, efficient tools made from high-tech materials: primarily steel, carbide, diamond particles, and ceramics.1,2 They are made in different sizes, shapes, and grits and serve a variety of needs.3 Some individual manufacturers, in fact, make so many types of burs that it affords the clinician nearly unlimited treatment options.
Anatomy of a Bur
Each bur comprises 3 parts: the shank, neck, and head.1 The shank, which is inserted into the handpiece, is usually the longest part of the bur. The neck comes next and it is connected to the head, which contains the cutting blade or the bur. Carbide burs are available in numerous shapes, and their heads contain blades of various configurations.1
An important aspect of the bur is the blade’s angle and positioning, as this determines the bur’s use.1 Diamond burs are generally favored for cutting through porcelain fixtures.1 Some burs are designed to work in soft, carious dentin whereas others can cut through the hardest composite materials.1 Burs come in several different shapes, including round, straight, and conical.3 The bur’s shape dictates the procedure for which it is used.3 In general, round burs are for the removal of large amounts of tooth decay, flat-end burs remove tooth structure, and smaller, more pointed burs are implemented when precise cutting is needed.3 Some burs contain cross-cuts, which are striations that enhance the stability of the cutting blade and reduce vibrations, thereby enhancing their precision by making them less apt to go off-target.1,3
Choosing the Right Grit
As with sandpaper, diamond burs come in a variety of grits. The greater the coarseness the more tooth surface will be removed. Finer grits are used when closer attention to detail is required. For example, restorations often require a finer grit bur to smooth rough edges and margins.
The following are some of the different types of burs and diamonds and their uses4:
Diamond ceramic polishers: These allow the dentist to gross trim, reduce and contour, and pre-polish. They are available in a variety of sizes, shapes, and grits.
• Finishers: These are used to trim and finish composite materials as well as debond orthodontic procedures.
• Diamond burs: Zirconia and lithium disilicate materials are difficult to cut through, making diamond burs the tool of choice.
• Carbides: These are available in numerous blade configurations, shank styles, and angles for best access to different parts of the tooth.
• Diamonds with ceramic bond: These abrasives are used on extremely hard materials.
• Endodontic access burs: These burs have a long, tapered shape that creates a funnel shape in the tooth for easier access to root canals.
• Flat-end taper carbide burs: These burs enable “quick and free cut removal of tooth structure.”
• Flat-end cylinder carbide burs: These are used for “free-cut removal of tooth structure with reduced chatter and breakage.”
• Gold finishing burs: These allow dental materials to be smoothly shaped and finished.
• Carbide crown cutters: These easily cut through nonprecious alloys and gold.
• Metal-cutting carbides: These are used for crown removal and endodontic access.
• Diamond grinders: These allow for cutting of ceramic-fused-to-metal alloys, titanium alloys, hard zirconium oxide ceramics, and more.
Final Thought
Although most burs are designed to resist wear and tear, they do tend to wear out quickly.3 Clinicians need to be aware of this, because a dull bur could damage a tooth and/or cause a patient to feel pain. Many burs are available in sterile, single-use packages, allowing the dental office to save time on sterilizing and autoclaving dental tools.3
There are many different types of burs from which to choose, but ultimately the dentist must use those with which he or she is most comfortable. This large variety of tools allows each patient case to be planned in advance so that the best burs are used.
References
1. Little D. Handpieces and Burs: The Cutting Edge. ADA CERP. www.stylusatc.com/sites/default/files/atc_handpiecesAndBurs.pdf. January 2009. Accessed July 13, 2013.
2. American Dental Association. ADA dental product guide. www.ada.org/productguide/c/22/Burs-All-Types. Accessed July 13, 2013.
3. Aegis Communications. Category spotlight: burs and diamonds: the best tools for the job. https://editiondigital.net/display_article.php?id=1324942. March 2013. Accessed July 14, 2013.
4. DentalAegis website. Burs/Diamonds. www.dentalaegis.com/products/burs-diamonds/listings. Accessed July 14, 2013.
