| Abstract|| |
A universally accepted standardization is of great value for any material or equipment that is used globally. A single number or name should represent the particular material or instrument throughout the world. Since the dental burs are used worldwide, a single standard numbering system, which gives a unique specification for each bur in any part of the world, is mandatory. Though the existing systems have tried to attain this goal, they have their own advantages and limitations that are explained in detail in this article. So, the idea of proposing a novel system is to formulate a simple way of mentioning each bur with its dimension and composition without the need for memorizing the numbers.
Keywords: Burs, numbering system, standardization
|How to cite this article:|
Hemamalathi SK, Abarajithan M, Kandaswamy D. A novel simplified numbering system for dental burs. Indian J Dent Res 2008;19:284-7
The first dental burs were made of stainless steel (SS) and were available in few simple head shapes; later, the carbide burs were introduced. With the advent of diamond points, the shapes that are available to today's dentist have also evolved to a greater extent from the past. But each manufacturer follows their own numbering system for the burs, which does not conform, to the shape and size of the bur. A universally accepted standard numbering system is of great value for any instrument that is used globally. Since the dental burs are used worldwide, a single standard numbering system, which gives a unique specification for each bur across the world, is mandatory. Though the existing systems have tried to achieve this goal, they are complex to memorize and hence difficult for practical usage. So, the idea of proposing a novel system is to formulate a simple way of mentioning each bur with its dimension and composition without the need for memorizing the numbers.
|How to cite this URL:|
Hemamalathi SK, Abarajithan M, Kandaswamy D. A novel simplified numbering system for dental burs. Indian J Dent Res [serial online] 2008 [cited 2020 Sep 18];19:284-7. Available from: http://www.ijdr.in/text.asp?2008/19/4/284/44528
| Brief History|| |
The SS White Company was the first to introduce a numbering system in 1891 for their first machine-made dental burs. This was then adopted by other companies and followed without any modifications till 1955. Later on, the American dental association (ADA) adopted the nomenclature with minor modifications and this system is being followed universally till date.
The burs were grouped under 9 shapes and 11 sizes. The ¼ and ½ designations were later added when smaller sized instruments were introduced. The first introduced burs had continuous blade edges; hence, when crosscut burs were introduced, the number 500 was added to their original designation. Similarly, 900 was added to the original designation for the burs which were end cutting only. ,
Since this original numbering system (introduced by SS White) is easy for practical usage, the ADA size numbers were also similar for most of the burs except 245 and 271, which were designated as 330L and 171, respectively. 
This system is confined only to SS and tungsten carbide burs. Diamond instruments are not included in this earlier system.
The ISO specification 6360
In 1979, international standards organization (ISO) gave a numbering system for dental burs. They gave a 15-digit number for specifying a particular bur. Each 3 digits represented a specific parameter in the bur, and hence, the 15-digit number for a bur will give information about the bur on five aspects. ,
The first set of 3 digits specifies the material of the cutting head. The designation 330 represents SS cutting head, 500 represents tungsten carbide, whereas 806 and 807 represent diamond instruments. 806 and 807 burs are manufactured by electroplating and sintering processes, respectively.
The second set of 3 digits represents the shank form of the bur. 103, 104, and 105 represent the straight hand-piece burs. They all have a diameter of 2.35 mm and a varied shank length of 34 mm, 44 mm, and 65 mm, respectively. 124 signifies a shank diameter of 3 mm and this is used for laboratory purposes.
202, 204, 205, and 206 represents latch-type contra angle hand-piece burs. 202 is for shank length of 16 mm, 204 for 22 mm, 205 for 26 mm, and 206 for 34 mm, of which 204 is the most common shank configuration.
The most commonly used friction grip burs are represented by 313, 314, 315, and 316, with a shank diameter of 1.6 mm. 313 represents a shank length of 16 mm, 314 represents 19 mm and is the most commonly used type. 315 and 316 represent 21 and 25 mm, respectively.
The third set of 3 digits represents the shape of cutting head.The round head is represented by 001, inverted cone by 010, cylindrical head by 107, conical head by 168, pear-shaped head by 237, flame-shaped head by 243, bud-shaped head by 260, torpedo-shaped head by 284, and lens-shaped head by 303
The fourth set of 3 digits applies only to diamond points. They represent the grit size of diamond instruments. The designation 494 is for grit size of 15 microns (super fine), 504 is for 30 microns (extra fine), 514 is for 50 microns (fine), 524 is for 100-120 microns (medium grit), 534 is for 135-140 microns (coarse grit), and 544 is for 180 microns (extra coarse). If the bur is not a diamond point, 000 needs to be used in the place.
The fifth set of 3 digits represents the diameter of the bur head. It is represented by the diameter in millimeter divided by 100. For example, if the diameter is 1.6 mm, it is represented as 016.
Thus, for example, a designation of 807314001524008 represents a diamond point for a standard friction grip hand-piece that has a round head of medium grit with a head diameter of 0.8 mm. Though the system is convincing, it is difficult to practice in daily routines
The advantages of original numbering system adopted by the ADA are:1) Since this system is followed from a long time, the manufacturers and the users have got used to it and it is difficult for both to adapt to a new system unless it is very simple and avoids confusion with that of the existing one.
The ISO numbering system, introduced later is neither simple nor avoids confusion. This might be the vital reason for the users to still adhere to the original system.
Each number not only denotes the shape of the bur but also its head diameter, and all this information is represented with just two or three digits. This is the most important reason for this system to be still followed compared to its counterpart (ISO system), which has 15 digits to give information about the burs. For example, 68 represents a straight fissure bur with a head diameter of 1 mm, whereas the same bur according to the ISO system has to be mentioned as 500314107000010.
The disadvantages of this system are:
The numbering was done starting from 1 for round burs and proceeded in an ascending order for the available bur head sizes in the same shape and then to the next shape. Since all the head shapes did not have all the head sizes, it has led to confusion. Memorizing this table [Table 1] is the only way with which the system can be followed, which is neither logical nor descriptive and also, this system does not give room for any new burs to be included into the original system.
The ISO system
This system attempts to give a specific number containing 15 digits to each bur that gives an exhaustive description of the bur. The details include the shank form, shank length, material of the cutting head, head diameter, if it is diamond pointed the coarseness of the grit, and the head shape. The system is said to be an ideal one providing maximum details about the instrument to the user. But too many parameters need to be memorized making it difficult to practice.
The proposed new simplified system
To overcome the problems with the existing systems, we have tried to formulate a new system that will be much simple yet descriptive and practical to use. Instead of assigning numbers for all the parameters, a combination of alphabets and numbers are used, so that the user will find it easy. This will also be practical as the user need not memorize any of the parameters
The new implified nomenclature
The first two alphabets specify 'the shape of the bur' - the first paramater. RD for round bur, bd for bud-shaped bur, pr for pear-shaped bur, sf for straight fissure bur, tf for tapering fissure bur, ts for torpedo-shaped bur, fs for flame-shaped bur, ic for inverted cone bur, wl for wheel-shaped bur, fs for football-shaped bur, ec for end-cutting bur, and eb for endo bur.
The second parameter specifies the 'maximum head diameter'. Here, the diameter (in mm) is being multiplied by 10 to make it a whole number. 0.5 as 5, 0.6 as 6, etc.
The third parameter specifies the 'maximum length of the bur head'. This value is also converted into a whole number by multiplying it by 10 and is included next to the previous number followed by a space to indicate separation.1.2 as 12, 3 as 30, etc.
The fourth parameter specifies the 'material of the cutting head'. For this, the alphabets D (diamond), C (carbide), or S (steel) is added based on the material. If the bur is a regular friction grip bur, 'FG' is included to the designation. If it is a short-shank friction grip bur, the suffix 'SS' is added before the material of the cutting head. If it is a long-shank friction grip bur, the suffix 'IS' is added before the material of the cutting head.
So, a straight fissure diamond point with head diameter of 1.2 mm, head length 3.0 mm with a normal friction grip shank will have the designation 'SF 12 30 DFG'.
If the same bur has a short shank, it will have the designation "SF12 30 SS DFG"; and if it has a long shank, it will be "SF12 30 IS DFG".
If it is a latch-type bur, 'LH' is added after the designation; and for a straight hand-piece bur 'SH' is added. Thus, an inverted cone carbide bur with the maximum head diameter of 1.2 mm, head length 1 mm, which has a latch-type shank will have the designation 'IC 12 1O CLH'.
In case of special bur designs like the endo access bur, which is a combination of two head shapes, 'EB' (endo bur) is assigned for the head shape, and the maximum head diameter among the two shapes alone can be used followed by the total head length, for example, EB 12 40 DFG. In case of the end-cutting bur, the head length has no importance, and hence, can be omitted.
Since the color coding given in the diamond points to specify the coarseness of the grit is simple to follow, this can be added at the end of the designation. In case of multi-fluted carbide burs, the number of flutes can be added at the end.
For easy identification, laser marking of the number can be done in the shank of the bur itself.
| Comments|| |
This system is self-explanatory and provides ample guidance with regard to its interpretation and usage. The designation gives information about the head shape, maximum head diameter, the head length, material of the cutting head, shank length, and the shank design. Thus, all the vital information that the ISO system provides are given in this system. The main advantage of this system over the others is that the user need not memorize any parameters in the system. Furthermore, the system can accommodate any number of new burs when they are introduced in near future [Table 2].
Mentioning a bur just as a 'straight fissure diamond' can be easier for common usage, but this can be done only between two persons or a group where each knows what exactly the other person means. But for global communication and usage, a simplified yet a standardized numbering system is mandatory. The proposed numbering system is a sincere attempt by us to formulate a nomenclature, which will be a much easier and standardized way for mentioning a bur. A change in the numbering system may not be easily accepted globally initially, but when the advantages of the system are considered it may slowly be adopted in the future.
| References|| |
|1.||Roberson TM, Heymann HO, Swift EJ. Studervant's The art and science of operative dentistry. 4th ed. Mosby Inc.; p. 330-4. |
|2.||Charbeneau GT. Principle and practice of operative dentistry. 3 rd ed. First Indian Reprint. Varghese Publishing House; 1988. p. 149. |
|3.||Council on dental research adopts standards for shapes and dimensions of excavating burs and diamond instruments. J Am Dent Assoc 1963;67:943. |
|4.||International Standards Organization: specification 6360-6364, numbering system for dental burs. Available from: http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=37301 - 45k. [last accesses on 2006 Sep 4]. |
|5.||Jedynakiewicz NM. A practical guide to technology in dentistry. Wolfe Publishing; 1992. p. 58-64. |
Senthil Kumar Hemamalathi
Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Alapakkam Main Road, Maduravoyal, Chennai - 600 095
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2]