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New American Dental Association Specification No. 23 for Dental Excavating Burs Adopted
New American Dental Association Specification No.
2 3
for dental excavating burs adopted
Council on Dental Materials and Devices T he follow ing new A m erican D ental A ssociation Specification N o. 23 for D ental E xcavating Burs has been approved by the C ouncil on D ental M a terials and D ev ices o f the A m erican D ental A sso ciation. Progress continues on a specification for diam ond rotary instruments. T he specification for dental excavating burs covers tw o types— steel and carbide. T he burs are classified as to the type o f handpiece with w hich they are used. T he specification includes requirem ents that lim it the eccentricity, specify the m inim um cutting ability and durability o f the instrum ents, and sp e cify the neck strength for the burs. T h e specifica tion test m ethods for determ ining cutting ability and durability are based on abusive slow speed tests. A lthough it is desirable that a high speed test m ethod be used, only a few studies, as yet, have been so conducted as to correlate such m eth ods to clinical application. U n til this inform ation is developed it is believed that the abusive tests present in the specification w ill define satisfactory cutting instruments. Such tests require a measured cut in brass w ithin a specified tim e lim it for m ini mum cutting perform ance and a sp ecified depth o f cut for 25 h oles into p late glass for th e minimum durability o f a bur. T he m axim um eccentricity (runout) o f 0 .0 0 2 inch for carbide and 0 .0 0 3 inch for steel burs in sures true running instruments if the chucks or other fitting parts o f the handpiece are true. A n additional requirem ent lim iting surface rough n ess o f the shank o f friction grip instruments m in im izes any possib le dam age to the chuck on inser tion and rem oval o f the burs. The specification was prepared by a subcom m ittee o f the form er Specifications C om m ittee, D ental M aterials Group, International A ssocia
tion for D ental R esearch. T he C ouncil w ishes to acknow ledge with thanks, the work o f the subcom m ittee members: G. T. Charbeneau, (chairm an), U niversity o f M ichigan, A nn Arbor, M ich; W. F. A ndrovette, S. S. W hite C o, Staten Island, N Y ; W illiam B oggs, Kerr M anufacturing C o., R om u lus, M ich; H . E. Ertle, R ansom & R andolph, T o ledo, O hio; F. A . Peyton, U niversity o f Florida, G ainesville, Fla; K. H. Strader, Surgident, Ltd., R ichm ond, V a; and J. W. Stanford, (secretary), A m erican D en tal A ssociation, C hicago. American Dental Association Specification No. 23 for dental excavating burs Approved June 1969. Effective June 1, 1971.
1. Scope and Classification 1.1 Scope. This specification is for burs suitable for use with dental straight and angle handpieces. 1.2 Types, classes and sizes. The dental burs covered by this specification shall be o f the following types, classes and sizes. 1.2.1 Types. Dental burs covered by this specifi cation shall be o f the following types: Type I Steel burs Type II Carbide burs 1.2.2 Classes. Dental burs covered by this speci fication shall be of the following classes: Class la Angle handpiece— latch type Class lb Angle handpiece— latch type, short neck Class 2 Straight handpiece Class 3a Angle handpiece— taper shank Class 3b Angle handpiece— taper shank, short neck Class 4a Angle handpiece— friction grip Class 4b Angle handpiece— friction grip, short neck Class 5 Angle handpiece— cone socket Class 6 Angle handpiece— sleeve bearing Class 7 Angle handpiece— flange type Class 8 Angle handpiece— miniature friction grip 1.2.3 Sizes Dental burs covered by this specifica tion shall be of the sizes shown in Table 1. 961
Table 1 ■ Head and neck dimensions. H ead S ize
S h ape
M in. No. B ia d e s
D ia m e te r’ ± 0 .0 8 ± 0 .0 0 3 mm.
V2 1 2 3 4 5 6 7 8 9 11
R ound " " ” » » » "
" " "
111/2 12 14 16
W heel "
331/2
In v e rte d co n e
34 35 36 37 38 39 40 551/2
56 57 58 59 60 61 62 170
171 502 504 556
557 558 559 560 561 562 •563 700
701 702 703 901
902 903 957 958 959
" "
" " " " " "
P lain fis s u re " " " " " "
T a p e re d fis s u re n o n c ro s s c u t Round c ro s s c u t S tra ig h t fis s u re c ro s s c u t
T ap ere d fis s u re c ro s s c u t
" " " End and sid e c u ttin g
" " End c u ttin g
" "
in.
L en gth M in. T ype I mm.
in.
C a rb id e Len gth M in . T y p e II mm.
T a p e r/C o n e a n g le ito ta l b oth sid e s) Type I
in.
T y p e II
N eck D ia m e te r M ax. mm.
De 3 ree
in.
6 6 6 6 6 6 8 8 8 10 10
.64 .81 1.02 1.22 1.42 1.62 1.85 2.08 2.31 2.54 3.05
0.025 0.032 0.040 0.048 0.056 0.064 0.073 0.082 0.091 0.100 0.120
0.46 0.58 0.71 0.86 0.99 1.14 1.30 1.50 1.68 2.03 2.69
0.018 0.023 0.028 0.034 0.039 0.045 0.051 0.059 0.066 0.080 0.106
0.31 0.5 8 0.61 0.71 0.8 2 1.02 1.24 1.47 1.68 1.78 2.4 4
0.012 0.023 0.024 0.028 0.032 0.040 0.049 0.058 0.066 0.070 0.096
6 6 6 6
0.64 0.81 1.22 1.62
0.025 0.032 0.048 0.064
0.23 0.25 0.31 0.36
0.009 0.010 0.012 0.014
0.2 3 0 .25 0.2 3 0 .3 6
0.009 0.010 0.009 0.014
—
0.51 0.64 0.74 0.84
6
0.64
0.025
0.41
0.016
0.31
0.012
10-22
6-16
0.51
0.020
6 6 6 6 6 6 8 6
0.81 1.02 1.22 1.42 1.62 1.85 2.08 0.64
0.032 0.040 0.048 0.056 0.064 0.073 0.082 0.025
0.51 0.61 0.74 0.89 1.12 1.40 1.70 2.44
0.020 0.024 0.029 0.035 0.044 0.055 0.067 0.096
0.4 6 0.4 9 0.61 0.71 1.02 1.30 1 .4 5 2 .19
0.018 0.019 0.024 0.028 0.040 0.051 0.057 0.086
10-22 10-22 10-22 10-22 10-22 10-22 10-22 0-2
6-16 6-16 6-16 6-16 6-16 6-16 6-16 0-2
0.64 0.71 0.79 0.86 0.96 1.08 1.17 0.64
0.025 0.028 0.031 0.034 0.038 0.042 0.046 0.025
6 6 6 6 6 6 6 6
0.81 1.02 1.22 1.42 1.62 1.85 2.08 1.02
0.032 0.040 0.048 0.056 0.064 0.073 0.082 0.040
2.69 3.00 3.25 3.56 3.86 4.17 4.47 3.17
0.106 0.118 0.128 0.140 0.152 0.164 0.176 0.125
3.61 3.61 3.61 3.86 3.86 3.91 4.22 3.61
0.142 0.142 0.142 0.152 0.152 0.154 0.166 0.142
0-2 0-2 0-2 0-2 0-2 0-2 0-2 4-8
0-2 0-2 0-2 0-2 0-2 0-2 0-2 4-8
0.86 1.08 1.22 1.37 1.50 1.60 1.65 0.96
0.034 0.042 0.048 0.054 0.059 0.063 0.065 0.038
6 6
1.22 1.02
0.048 0.040
3.33 0.71
0.131 0.028
3-61 0.61
0.142 0.024
4-8
4-8
—
—
1.17 0.74
0.046 0.029
6 6
1.42 0.81
0.056 0.032
0.99 2.69
0.039 0.106
0 .74 3.61
0.029 0.142
0-2
0-2
0.91 0.86
0.036 0.034
6 6 6 6 6 6 6
1.02 1.22 1.42 1.62 1.85 2.08 2.31
0.040 0.048 0.056 0.064 0.073 0.082 0.091
3.00 3.25 3.56 3.86 4.17 4.47 4.83
0 .1 1 8 ’ * 3.61 0.128* * 3.61 0.140* ‘ 3.86 3.86 0.152 0.164 3.91 0.176 4.22 0.190 4.58
0.142 0.142 0.152 0.152 0.154 0.166 0.180
0-2 0-2 0-2 0-2 0-2 0-2 0-2
0-2 0-2 0-2 0-2 0-2 0-2 0-2
1.08 1.22 1.37 1.50 1.60 1.65 1.68
0.042 0.048 0.054 0.059 0.063 0.065 0.066
6 6 6 6
1.02 1.22 1.62 2.08
0.040 0.048 0.064 0.082
3.17 3.33 3.86 4.42
0.125* * 0.131* * 0.152* * 0.174
3.61 3.61 3.86 3.86
0.142 0.142 0.152 0.152
4-8 4-8 4-8 4-8
4-8 4-8 4-8 4-9
0.96 1.17 1.45 1.63
0.038 0.046 0.057 0.064
6 6 6
1.02 1.22 1.42
0.040 0.048 0.056
3-61
0.142
6 6 6
1.02 1.22 1.42
0.040 0.048 0.056
3.61
0.142
—
—
—
___
—
—
—
___
—
—
—
___
—
___
—
___
—
—
—
—
___
___
—
—
—
—
—
0.51 0.64 0.74 0.84 0.91 1.02 1.12 1.19 1.27 1.37 1.52
0.020 0.025 0.029 0.033 0.036 0.040 0.044 0.047 0.050 0.054 0.060 0.020 0.025 0.029 0.033
* D e s ig n a te s d ia m e te r a t la rg e s t pla c e . ’ * 0.095 fo r c la s s e s 1b, 3b, 4b a n d 8 on ly .
2. Applicable Specifications and Standards 2.1 Specifications. There are no other specifi cations applicable to this specification. (Copies o f American Dental Association specifications may be obtained on application to the Council on Dental Materials and Devices, American Dental Association, 211 E Chicago Ave, Chicago, 111 60611. 2.2 Standards. The following ASTM standard o f 962 ■ JADA, Vol. 81, October 1970
the issue in effect on the date o f certification shall be made a part o f this specification: ASTM Standard D -5-52 Penetrometer Point. 3. Requirements 3.1 Construction. 3.1.1 Type I burs shall be o f the type convention ally known to the dental trade as “steel burs.”
.0919
-0700
Diameter slightly
F ig l
■
S h a n k e n d o f m a n d r e l: c la s s 1.
.052
F ig 2 ■ S h a n k e n d o f m a n d r e l: c la s s 2.
All dimensions in inches
3.1.2 Type II burs shall be of the type conven tionally known to the dental trade as “carbide burs.” 3.2 Dimensions. 3.2.1 H e ad and neck dimensions. The head and neck dimensions for all sizes of burs shall be as shown in Table 1. 3.2.2 Shank dimensions. The shank dimensions for all classes o f burs shall be as given in Table 2 and Figures 1 through 7. 3.2.2.1 In those instances where the values o f Ta ble 2 indicate maximum and minimum shank and overall lengths differing by more than 1.02 mm (0.040 inch), each manufacturer shall designate a normal design length within the limits o f Table 2. A ll bur lengths shall fall within ± 0 .5 1 mm (0.020 inch) o f the designated value as well as within the limits o f Table 2. 3.3 R unout. 3.3.1 Type I burs. The total indicated runout shall not exceed 0.08 mm (0.003 inch) when mea sured as specified in 4.2.4. 3.3.2 Type I I burs. The total indicated runout should not exceed 0.05 mm (0.002 inch) when mea sured as specified in 4.2.4. 3.4 Cu ttin g ability. The total time required for a
sample o f five burs, selected as specified in 4.1.3, to cut a distance of 0.51 mm (0.020 inch) each in brass when tested as specified in 4.3.1, shall not exceed that indicated in Table 3, column 5, for each size. 3.5 D urability. The total depth o f holes cut in glass by a sample of five burs selected as specified in 4.1.3 when tested as specified in 4.3.2, shall be no less than that indicated in Table 4 for each type and size. 3.6 B u r neck strength. N one o f a sample of five burs selected as specified in 4.1.3 shall break, nor take a permanent set o f more than 0.08 mm (0.003 inch) when tested as specified in 4.3.3. 3.7 Surface roughness. The surface roughness o f the shanks o f Class 4a, angle handpiece— friction grip instruments, Class 4b, angle handpiece— fric tion grip, short neck instruments, and Class 8, angle handpiece— miniature friction grip instruments shall not be more than a RMS value o f 20 micro-inches (root-mean-square variation 20 millionths o f an inch) when tested as specified in 4.2.5. 4.
Sampling, Inspection and Test Procedures Sampling procedures. Sampling and testing for certification shall be by type and size. A ll classes 4.1
REPORTS OF COUNCILS AND BUREAUS ■ 963
__/
Optionasl dimension
n r ■ I bmi" )S3—!I---------------J- - 1 -
Fig 3 ■ Shank end of mandrel: class 3.
Optional dimension Cmin, .003max .
OPTION OPTIONAL DIMENSION A B C D NO. All dimensions in inches
I II III
.010
_
_
-
.008 .001
.001 .001 .006-,008 -
.001- .006
May have flat end if diameter of fiat is less than 0.052 in. Angle must be 60° or less
Fig 4 ■ Shank end of mandrel: classes 4 and 8.
Rounded end no sharp edfe blend with o.d.
All dimensions In Inches Dimension
class 4a 0.400-0.545 class 4b 0.300-0.500 class 8 0.355-0.395 class 4a 0.0624-0.0631 class 4b 0.0624— 0.0631 class 8 0.0420-0.0425
Fig 5 ■ Shank end of mandrel: class 5.
All dimensions in inches
964 ■ JADA, Vol. 81, October 1970
Fig 6 ■ Shank end of mandrel: class 6.
F ig 7 ■ S h a n k e n d o f m a n d r e l: c la s s 7.
of burs o f one type and size made by one manufac turer shall be considered as a group for certification purposes and shall be accepted or rejected together. Sampling shall be done by a modified double sam pling procedure with the combined first and second samples, called a “certification sample,” being ob tained together. When five or less sizes o f one type are submitted simultaneously for certification, each size shall be sampled. When more than five sizes o f one type are submitted simultaneously, certification samples shall be obtained for five sizes chosen to be representative o f the sizes submitted. The certifica tion samples shall be selected so as to include as far as possible one sample of each class in which the burs are supplied. If each o f the certification samples test ed complies with the specification, all of the sizes submitted simultaneously shall be accepted for certi fication. If one or more o f the certification samples fails to comply with the specification, all o f the sizes submitted simultaneously shall be rejected but may
be resubmitted for certification at a later date. 4.1.1 Certification sample. A certification sam ple shall consist o f 105 burs o f one type, size, and class, as indicated by the package identification. It shall be obtained by open market procurement in at least four widely separated localities in the United States, no more than 30 burs being obtained in one place. 4.1.2 Inspection samples. A first sample o f 35 burs shall be chosen at random from the certifica tion sample and inspected in accordance with the provisions o f 4.2 for compliance with 3.1, 3.2, 3.3, 5.1, 5.2, and 5.3. If a second sample is required, the remaining 70 burs o f the certification sample shall be employed for this purpose. 4.1.3 Test samples. A sample o f five burs shall be selected at random from among the burs inspect ed as specified in 4.2, no more than one bur, how ever, being selected from any one package. Three REPORTS OF COUNCILS AND BUREAUS ■ 965
Table 2 ■ Shank dimensions. C la s s
m m. 1a 1b 2 3a 3b 4a 4b 5 6 7 8
22.22 18.41 44.45 18.79 17.39 19.17 16.25 19.05 26.16 23.62 14.09
+ 0.25 + 0.38 + 0.25 0.51 ± 0.25 ± 0.89 ± 0.64 ± 0.25 ± 0.51 ± 0.25 ± 0.51
0.875 0.725 1.750 0.740 0.685 0.755 0.640 0.750 1.030 0.930 0.555
S h ank Len ath
D ia m e te r
O v e r-a ll Length
M in. in.
m m.
in.
± ± ± ± ± ±
2.334-2.360 2.334-2.360 2.334-2.360 2.329-2.360 2.329-2.360 1.585-1.603 1.585-1.603 3.68 -3.81 3.772-3.779 2.336-2.346 1.066-1.079
0.0919-0.0929 0.0919-0.0929 0.0919-0.0929 0.0917-0.0929 0.0917-0.0929 0.0624-0.0631 0.0624-0.0631 0.145 -0.150 0.1485-0.1488 0.0920-0.0924 0.0420-0.0425
0.010 0.015 0.010 0.020 0.010 0.035 ± 0.025 ± 0.010 ± 0.020 ± 0.010 ± 0.020
Max.
mm.
in.
m m.
in.
10.66 9.14 27.94 5.321 5.321 10.16 7.62 9.39 13.56 13.18 9.01
0.420 0.360 1.100 0.2095 0.2095 0.400 0.300 0.370 0.534 0.519 0.355
13.91 13.08 35.81 5.664 5.664 13.84 12.70 9.65 13.74 13.31 10.03
0.548 0.515 1.410 0.2230 0.2230 0.545 0.500 0.380 0.541 0.524 0.395
Table 3 ■ C utting ability. S ize
Brass T h ic k n e s s
mm. 1/2 1 2 3 4 5 6 7 8 9 11 111/2 12 14 16 331/2 34 35 36 37 38 39 40 551/2 56 57 58 59 60 61 62 170 171 502 504 556 557 558 559 560 561 562 563 700 701 702 703
in.
0.28 0.28 0.28 0.28 0.51 0.51 0.51 0.51 0.51 0.51 0.51
0.011 0.011 0.011 0.011 0.020 0.020 0.020 0.020 0.020 0.020 0.020
0.28 0.28 0.28 0.28 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.28 0,51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51
0.011 0.011 0.011 0.011 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 Ö.011 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020
D epth o f s e ttin g fo r c u t* m m.
in.
P ro je c tio n o f b u r end th ro u g h brass mm.
M a xim um to ta l m illin g tim e T ype I T ype II
in.
seconds
0.38 0.46 0.56 0.71 0.86 0.96 1.08 1.17 1.32 1.42 1.68
0.015 0.018 0.022 0.028 0.034 0.038 0.042 0.046 0.052 0.056 0.066
0.10 0 .18 0.28 0.44 0.44 0.46 0.56 0.66 0.81 0.91 1.17
0.004 0.007 0.011 0.017 0.017 0.018 0.022 0.026 0.032 0.036 0.046
45 45 35 35 25 25 25 25 25 25 25
40 40 25 25 25 25 25 25 25 25 25
0.41 0.41 0.41 0.41 0.64 0.64 0.64 0.64 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 ' 1.52 0.51 0.86 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52
0.016 0.016 0.016 0.016 0.025 0.025 0.025 0.025 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.020 0.034 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060
0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 0.28 0.44 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02
0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.011 0.017 0.040 0.040 0.040 0.040 0.040 0.040 0.040 ' 0.040 0.040 0.040 0.040 0.040
120 120 100 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 35 25 50 50 50 50 50 50 50 50 50 50 50 50
25 25 25 25 50 50 50 50 50 50 50 50 50 50 50 50 50 50 25 25 50 50 50 50 50 50 50 50 50 50 50 50
• D epth o f b u r tip b e lo w s u rfa c e o f te s t s trip .
such samples shall be chosen and tested, one each for compliance with the requirements o f 3.4, 3.5, and 3.6 by the methods specified in 4.3 If the certifica tion sample fails the inspection o f 4.2, it fails the 966 ■ JADA, Vol. 81, October 1970
specification, and the tests o f 4.3 need not be per formed. 4.2 Inspection procedures. Visual inspection without magnification shall be used in determining
Table 4 ■ Durability. S iz e
Table 5 a Classification of defects by classes—major.
M in im u m to ta l deDth o f Type I mm.
V2 2 3 4 5 6 7 8 9 11
111/2 12 14 16 331/2 34 35 36 37 38 39 40 551/2 56 57 58 59 60 61 62 170 171 502 504 556 557 558 559 560 561 562 563 700 701 702 703
3.18 3.18 3.81 3.81 4.44 4.44 4.44 4.44 3.81 3.81 3.81 3.18 3.18 3.81 4.44 3.18 3.18 3.81 3.81 4.44 4.44 4.44 4.44 3.18 3.18 3.81 3.81 4.44 4.44 4.44 4.44 3.81 3.81 3.81 4.44 3.81 4.44 4.44 4.44 4.44 4.44 4.44 4.44 3.81 4.44 4.44 4.44
25 h o le s
C la ss
a
Type II in.
0.125 0.125 0.150 0.150 0.175 0.175 0.175 0.175 0.150 0.150 0.150 0.125 0.125 0.150 0.175 0.125 0.125 0.150 0.150 0.175 0.175 0.175 0.175 0.125 0.125 0.150 0.150 0.175 0.175 0.175 0.175 0.150 0.150 0.150 0.175 0.150 0.175 0.175 0.175 0.175 0.175 0.175 0.175 0.150 0.175 0.175 0.175
mm. 6.10 8.26 10.16 10.16 10.16 10.16 10.16 10.16 10.16 10.16 10.16 6.10 8.26 10.16 10.16 6.10 6.10 7.62 10.16 10.16 10.16 10.16 10.16 6.10 8.26 10.16 10.61 10.16 10.16 10.16 10.16 8.26 8.89 10.16 10.16 8.89 10.16 10.16 10.16 10.16 10.16 10.16 10.16 7.62 10.16 10.16 10.16
in. 0.240 0.325 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.240 0.325 0.400 0.400 0.240 0.240 0.300 0.400 0.400 0.400 0.400 0.400 0.240 0.325 0.400 0.400 0.400 0.400 0.400 0.400 0.325 0.350 0.400 0.400 0.350 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.300 0.400 0.400 0.400
2
3a 3b 4a 4b 5 6 7 8
D ia m e te r o f shan k e x c e e d s m a xim um in T a b le II. D -fla t d im e n s io n e x c e e d s 1.840 m m. (0.0725 in.). S h o u ld e r to g ro o v e m e a s u re m e n t le s s th a n 1.753 mm. (0.069 in .). W id th o f g ro o v e le s s th a n 0.864 m m. (0.034 in.). D ia m e te r o f g ro o v e o v e r 1.450 m m . (0.059 in.). D -fla t d im e n s io n e x c e e d s s p e c ific a tio n . S h o u ld e r to g ro o v e m e a s u re m e n t le s s th a n 5.321 m m. (0.2095 in .). W id th o f g ro o v e le s s than 0.940 m m. (0.037 in.) D ia m e te r o f g ro o v e o v e r 1.880 m m . (0.0740 in.). T a p e r a n g le o u ts id e o f 5 ° -3 ' -4 0 " —4 ° -5 3 ' -35". S h o u ld e r to g ro o v e m e a s u re m e n t m o re th a n 5.664 mm. (0. 2 230 in .).
C la s s ific a t io n o f d e fe c ts b y c la s s e s — m in o r . C lass
a
b
c
d
e
f
g
h
1a 1b
X X X X X X X X X X X
X X X X X X X X X X X
X X X X X X X
X X
X X X X X X X X X X X
X X X
X X X X X X X X X X X
X X X X X X X X X x X
2
3a 3b 4a 4b 5
6
7 8
a. b.
com pliance with the requirements of 3.1. Methods of inspection for compliance with 3.2 and 3.3 shall be as outlined below. 4.2.1 Quality level. All bur defects as deter mined by inspection shall be divided into major de fects and minor defects. Major defects shall include only those items that would prevent a bur from op erating. Minor defects shall be all other deviations from specifications that would tend to lower the quality o f the product. Acceptable quality levels shall be as follows: Type I Major defects 2.5 % defective. Minor defects 6.5% defective. Type II Major defects 1.5 % defective. Minor defects 4.0% defective. Major and minor defects for each type and class shall be as listed in Table 5. 4.2.2 C om pliance. When the number of defec tive units found in the first sample, after inspection as specified in 4.2, is equal to or less than the first
x X X X X X X X X X X
1a 1b
c. d. e. f. g. h. i. j. k.
X X X
X X
X X X
X X X X X
.
i
j
X X
X X
k
X X
X
X
X
T o ta l in d ic a te d ru n o u t e x c e e d s re q u ire m e n ts . Head d im e n s io n s o u ts id e of s p e c ific a tio n lim its w h en m e a s u re d to th e n e a re s t 0.025 m m . (0.001 in .). D ia m e te r o f sh a n k le s s than s p e c ifie d . O th e r fittin g d im e n s io n s not to s p e c ific a tio n . O v e r-a ll le n g th no t to s p e c ific a tio n . Length o f s tra ig h t shan k le s s than s p e c ifie d . N e ck d ia m e te r e x c e e d s s p e c ifie d v a lu e s . Head m is s h a p e n to e x te n t o f lo s in g id e n tity . P o or fin is h on shank. C u t-o ff on sh a n k no t as in d ic a te d in fig u re , C one a n g le on shan k o u ts id e o f s p e c ific a tio n .
acceptance number in Table 6, the certification sam ple complies. When the number o f defective units found in the first sample is equal to or greater than the first rejection number, the certification sample fails. When the number o f defective units found in the first sample is between the first acceptance and rejection numbers, a second sample shall be inspect ed. The number o f defective units found in the first and second samples shall be accumulated. If the cu mulative number o f defective units is equal to or less REPORTS OF COUNCILS AND BUREAUS ■ 967
Table 6 ■ Number of defects for acceptance and rejection. Acceptable Quality Level
1.5
2.5
4.0
6.5
Sample Sample Cumulative Ac. Re. Ac. Re. ^c. Re Ac. Re.* Size Sample Size F irs t
35
35
1
3
1
5
2
7
3
12
S e cond
70
105
2
3
4
5
6
7 11
12
* A c. = A c c e p ta n c e , Re. = R e je c tio n .
than the second acceptance number of Table 6, the certification sample complies. If the cumulative num ber o f defective units is equal to or greater than the second rejection number, the certification sample fails. 4.2.3 Dimensions. Inspection of head and shank diameters as required for all classes in 3.2 shall be made with tungsten carbide ring gauges checked reg ularly with mating plugs. The neck diameter shall be inspected with a calibrated blade-type micrometer caliper. The fitting dimensions of classes 1, 3, 5, 6, and 7 burs shall be checked with appropriate gauges with tungsten carbide faces. Overall length and other dimensions shall be checked with a standard tung sten carbide faced micrometer caliper or with a tool maker’s microscope. The toolmaker’s microscope or an optical comparator shall be used for measuring the cone angles. For a true reading of the cone angles, the reading must be made on one blade on one side o f the bur head; reading the angle by a par tial rotation o f the bur, equal to the spiral of the blade, in a vee-block. The angle so measured shall be doubled to give the cone angle. 4.2.4 R unout. The total indicated runout of the bur neck shall be measured to the nearest 0.01 mm (0.0005 inch). The bur shall be held in a vee-block or precision chuck and rotated slowly. A dial indi cator sensitive to 0.005 mm (0.0002 inch), equipped with a knife-edge foot, or other suitable equipment of equal accuracy, shall be employed. If a dial indi cator is used, it shall be mounted with the shaft per pendicular to the axis o f the bur and shall be so posi tioned that the foot contacts the bur neck at the point o f smallest diameter. The difference between the maximum and minimum dial indicator readings for one full rotation o f the bur shall be taken as the total indicated runout. 4.2.5 Surface roughness. The surface rough ness of the shanks o f instruments specified in 3.7 shall be determined by a Brush Surfindicator or equipment o f demonstrated equal quality. The sur face roughness shall be determined in the longitudi nal direction o f the straight portion o f the shank. 4.3 Test procedures. 4.3.1 C u ttin g ability.
A test sample o f five burs selected as specified in 4.1.3 shall be tested for cut ting ability as follows: 968 ■ JADA, Vol. 81, October 1970
4.3.1.1 Test material. The test material for the cutting ability test shall be 70-30 brass sheet cut to suitable size for use in the test equipment. The brass sheet shall have a Rockwell hardness o f B40-B65 and shall be o f two thicknesses: 24 and 29 B and S gauge (0.020 and 0.011 inch). The thickness o f brass used for each size bur is specified in Table 3. 4.3.1.2 Equipm ent. The equipment shall consist o f a precision chuck capable o f holding the burs to be tested, a movable carriage for the test material, and necessary accessories for measuring the time re quired to cut 0.51 mm (0.020 inch) within 0.5 second. The bur shall be positioned perpendicular to the brass test strip and the relative heights shall be ad justable so as to allow com pliance with the depth o f setting for cut as shown in Table 3. The test equip ment shall be so designed as to apply a constant 1 lb contact load between the bur and test strip, perpen dicular to the bur axis. 4.3.1.3 Procedure. A bur to be tested and a brass test strip o f the proper thickness shall be placed in the test apparatus and their relative heights adjust ed. The brass thickness, depth o f setting for cut, pro jection o f the bur end and the test load shall be made to comply with the values specified in Table 3. The bur shall be rotated at a speed o f 4350 ± 5 0 rpm and brought into contact with the edge o f the brass strip. A preliminary cut equal to at least half, but no more than one, bur diameter shall be made before making readings. The time required for the bur to cut a dis tance o f 0.51 mm (0.020 inch) shall be determined to ± 0 .5 second. 4.3.1.4 Com pliance. If the total time required for a test sample o f five burs to cut a distance o f 0.51 mm (0.020 inch) each is less than or equal to that shown in Table 3, the sample complies with the re quirement o f 3.4. If the total tim e exceeds that shown in Table 3, two more test samples o f five burs each shall be selected and tested in the same fashion. If both additional test samples comply, the certifica tion sample complies. If either fails, the certification sample fails. 4.3.2 D urability. A test sample of five burs se lected as specified in 4.1.3 shall be tested for dura bility as follows: 4.3.2.1 Test material. The test material for the durability test shall be crystal plate glass more than 3.18 mm (0.125 inch) thick having a Knoop hard ness number o f 450-510 with a 1 kg load. 4.3.2.2 Equipm ent. The equipment for the dura bility test shall consist of a true running chuck capa ble o f holding and rotating the bur being tested and a movable platform or carriage suitable for carrying the flat surface o f a glass test block into contact with the bur at an angle o f 22’/2 degrees from the axis of the bur. The machine shall be capable o f main taining a contact load of 1 lb perpendicular to the glass surface. 4.3.2.3 Procedure. A bur to be tested shall be
placed in the test apparatus and rotated at 1,550 ± 5 0 revolutions per minute. The glass test plate shall be slowly brought into contact with the bur and held in contact for a period of 2,000 revolutions. The glass plate shall then be removed so that a new portion of the flat surface is exposed to the bur for 2,000 revo lutions. Five such holes shall be made using turpen tine as a cutting fluid. The plate shall then be re moved and the depth o f the holes measured with a sharp point on a dial gauge sensitive to 0.005 mm (0.0002 inch). The point shall meet the require ments o f ASTM Standard D-5-52. 4.3.2.4 Com pliance. If the total depth o f the 25 holes cut by the five burs of the test sample equals or exceeds that specified in Table 4, the sample com plies. If the total depth of holes is less than that spe cified for the type and size of bur tested, two more test samples o f five burs each shall be chosen and tested in the same manner. If both o f these test sam ples comply, the certification sample complies. If either fails to pass, the certification sample fails. 4.3.3 N eck strength. A test sample o f five burs selected as specified in 4.1.3 shall be tested for neck strength as follows: 4.3.3.1 Equipm ent. The equipment for the neck strength test shall consist o f a suitable chuck for hold ing and rotating the bur to be tested, a loading de vice capable o f applying the designated loads through an anvil with a flat surface at an angle o f 22Vi de grees to the bur axis, and a measuring device similar to that o f 4.2.4 for measurement o f the total runout o f the bur. In the case of those classes which have shanks o f uniform diameter (Classes 1, 2, 4, and 7) the chuck shall grip at least 9.52 mm (0.375 inch) o f shank starting at the intersection o f neck and shank. All other classes o f bur shall be gripped by the chuck at all points normally gripped by the dental hand piece. 4.3.3.2 Procedure. The bur being tested shall be placed in the chuck and its total indicated runout shall be determined. The bur shall then be rotated to the position giving the highest deflection reading on the dial gauge. A load of the magnitude specified in Table 7 shall then be applied slowly at an angle o f 2 2 Vi degrees to the bur axis, in the direction which tends to increase the dial deflection reading. The load shall then be removed and the total indicated runout redetermined. 4.3.3.3 Compliance. A bur complies with this requirement if the neck does not break and if the to tal indicated runout does not increase by more than 0.08 mm (0.003 inch). If a bur breaks in the head dur ing the test, one bur per test sample may be replaced without prejudice to the results. The test sample com plies when all five burs comply individually. If the first test sample complies, the certification sample complies. If the first test sample fails, two addi tional test samples shall be chosen and tested in the same manner. If both o f these test samples comply,
Table 7 ■ Neck strength, nondamaglng test load. Size
T e s t Load
1 2 3 4 5 6 7 8 9 11 11V2 12 14 16 331/2 34 35 36
kg. 1.36 1.36 1.59 1.81 2.49 2.95 3.18 3.40 3.63 4.08 4.54 1.13 1.36 1.59 2.72 1.36 1.36 1.59 1.81
37 38 39 40 55V2 56 57 58 59 60 61 62 170 171 502 504 556 557 558 559 560 561 562 700 701 702 703
2.49 2.95 3.18 3.40 0.91 1.36 1.81 2.27 2.72 2.95 3.18 3.63 1.59 2.49 1.59 2.95 1.36 1.81 2.27 3.18 4.08 3.18 3.63 1.59 2.49 3.40 4.08
1/2
lbs. 30 30 3 5 40 5.5 6.5 7.0 7.5 80 9 0 10.0 2.5 3.0 3.5 6.0 3.0 3.0 3.5 4.0 5.5 6.5 7.0 7.5 2.0 3.0 4.0 5.0 6.0 6.5 7.0 8.0 3.5 5.5 3.5 6.5 3.0 4.0 5.0 7.0 ' 9.0 7.0 8.0 3.5 5.5 7.5 9.0
the certification sample complies. If either fails, the certification sample fails. 5. Preparation for Delivery 5.1 Packaging. Burs, other than those having corrosion-resistant shanks, shall be treated with a corrosion-preventing compound. A light rust-inhibiting oil shall be considered adequate for this purpose. Type I burs shall be packaged, six o f one type, class, and size, in a moisture resistant package. Each pack age o f six burs shall have a transparent window to render the heads o f the burs visible. Type II burs shall be packaged, either one or six per package, in suitable holders having covers with transparent w in dows. 5.2.1 L o t num bers. Each package o f burs shall be marked with a serial number, or a combination o f letters and numbers, which shall refer to the manu facturer’s records for that particular lot or batch. 5.2.2 Identification. A number, or letter, or combination thereof shall be placed on the bur pack age identifying the type, class, and size contained. REPORTS OF COUNCILS AND BUREAUS ■ 969
2 3
for dental excavating burs adopted
Council on Dental Materials and Devices T he follow ing new A m erican D ental A ssociation Specification N o. 23 for D ental E xcavating Burs has been approved by the C ouncil on D ental M a terials and D ev ices o f the A m erican D ental A sso ciation. Progress continues on a specification for diam ond rotary instruments. T he specification for dental excavating burs covers tw o types— steel and carbide. T he burs are classified as to the type o f handpiece with w hich they are used. T he specification includes requirem ents that lim it the eccentricity, specify the m inim um cutting ability and durability o f the instrum ents, and sp e cify the neck strength for the burs. T h e specifica tion test m ethods for determ ining cutting ability and durability are based on abusive slow speed tests. A lthough it is desirable that a high speed test m ethod be used, only a few studies, as yet, have been so conducted as to correlate such m eth ods to clinical application. U n til this inform ation is developed it is believed that the abusive tests present in the specification w ill define satisfactory cutting instruments. Such tests require a measured cut in brass w ithin a specified tim e lim it for m ini mum cutting perform ance and a sp ecified depth o f cut for 25 h oles into p late glass for th e minimum durability o f a bur. T he m axim um eccentricity (runout) o f 0 .0 0 2 inch for carbide and 0 .0 0 3 inch for steel burs in sures true running instruments if the chucks or other fitting parts o f the handpiece are true. A n additional requirem ent lim iting surface rough n ess o f the shank o f friction grip instruments m in im izes any possib le dam age to the chuck on inser tion and rem oval o f the burs. The specification was prepared by a subcom m ittee o f the form er Specifications C om m ittee, D ental M aterials Group, International A ssocia
tion for D ental R esearch. T he C ouncil w ishes to acknow ledge with thanks, the work o f the subcom m ittee members: G. T. Charbeneau, (chairm an), U niversity o f M ichigan, A nn Arbor, M ich; W. F. A ndrovette, S. S. W hite C o, Staten Island, N Y ; W illiam B oggs, Kerr M anufacturing C o., R om u lus, M ich; H . E. Ertle, R ansom & R andolph, T o ledo, O hio; F. A . Peyton, U niversity o f Florida, G ainesville, Fla; K. H. Strader, Surgident, Ltd., R ichm ond, V a; and J. W. Stanford, (secretary), A m erican D en tal A ssociation, C hicago. American Dental Association Specification No. 23 for dental excavating burs Approved June 1969. Effective June 1, 1971.
1. Scope and Classification 1.1 Scope. This specification is for burs suitable for use with dental straight and angle handpieces. 1.2 Types, classes and sizes. The dental burs covered by this specification shall be o f the following types, classes and sizes. 1.2.1 Types. Dental burs covered by this specifi cation shall be o f the following types: Type I Steel burs Type II Carbide burs 1.2.2 Classes. Dental burs covered by this speci fication shall be of the following classes: Class la Angle handpiece— latch type Class lb Angle handpiece— latch type, short neck Class 2 Straight handpiece Class 3a Angle handpiece— taper shank Class 3b Angle handpiece— taper shank, short neck Class 4a Angle handpiece— friction grip Class 4b Angle handpiece— friction grip, short neck Class 5 Angle handpiece— cone socket Class 6 Angle handpiece— sleeve bearing Class 7 Angle handpiece— flange type Class 8 Angle handpiece— miniature friction grip 1.2.3 Sizes Dental burs covered by this specifica tion shall be of the sizes shown in Table 1. 961
Table 1 ■ Head and neck dimensions. H ead S ize
S h ape
M in. No. B ia d e s
D ia m e te r’ ± 0 .0 8 ± 0 .0 0 3 mm.
V2 1 2 3 4 5 6 7 8 9 11
R ound " " ” » » » "
" " "
111/2 12 14 16
W heel "
331/2
In v e rte d co n e
34 35 36 37 38 39 40 551/2
56 57 58 59 60 61 62 170
171 502 504 556
557 558 559 560 561 562 •563 700
701 702 703 901
902 903 957 958 959
" "
" " " " " "
P lain fis s u re " " " " " "
T a p e re d fis s u re n o n c ro s s c u t Round c ro s s c u t S tra ig h t fis s u re c ro s s c u t
T ap ere d fis s u re c ro s s c u t
" " " End and sid e c u ttin g
" " End c u ttin g
" "
in.
L en gth M in. T ype I mm.
in.
C a rb id e Len gth M in . T y p e II mm.
T a p e r/C o n e a n g le ito ta l b oth sid e s) Type I
in.
T y p e II
N eck D ia m e te r M ax. mm.
De 3 ree
in.
6 6 6 6 6 6 8 8 8 10 10
.64 .81 1.02 1.22 1.42 1.62 1.85 2.08 2.31 2.54 3.05
0.025 0.032 0.040 0.048 0.056 0.064 0.073 0.082 0.091 0.100 0.120
0.46 0.58 0.71 0.86 0.99 1.14 1.30 1.50 1.68 2.03 2.69
0.018 0.023 0.028 0.034 0.039 0.045 0.051 0.059 0.066 0.080 0.106
0.31 0.5 8 0.61 0.71 0.8 2 1.02 1.24 1.47 1.68 1.78 2.4 4
0.012 0.023 0.024 0.028 0.032 0.040 0.049 0.058 0.066 0.070 0.096
6 6 6 6
0.64 0.81 1.22 1.62
0.025 0.032 0.048 0.064
0.23 0.25 0.31 0.36
0.009 0.010 0.012 0.014
0.2 3 0 .25 0.2 3 0 .3 6
0.009 0.010 0.009 0.014
—
0.51 0.64 0.74 0.84
6
0.64
0.025
0.41
0.016
0.31
0.012
10-22
6-16
0.51
0.020
6 6 6 6 6 6 8 6
0.81 1.02 1.22 1.42 1.62 1.85 2.08 0.64
0.032 0.040 0.048 0.056 0.064 0.073 0.082 0.025
0.51 0.61 0.74 0.89 1.12 1.40 1.70 2.44
0.020 0.024 0.029 0.035 0.044 0.055 0.067 0.096
0.4 6 0.4 9 0.61 0.71 1.02 1.30 1 .4 5 2 .19
0.018 0.019 0.024 0.028 0.040 0.051 0.057 0.086
10-22 10-22 10-22 10-22 10-22 10-22 10-22 0-2
6-16 6-16 6-16 6-16 6-16 6-16 6-16 0-2
0.64 0.71 0.79 0.86 0.96 1.08 1.17 0.64
0.025 0.028 0.031 0.034 0.038 0.042 0.046 0.025
6 6 6 6 6 6 6 6
0.81 1.02 1.22 1.42 1.62 1.85 2.08 1.02
0.032 0.040 0.048 0.056 0.064 0.073 0.082 0.040
2.69 3.00 3.25 3.56 3.86 4.17 4.47 3.17
0.106 0.118 0.128 0.140 0.152 0.164 0.176 0.125
3.61 3.61 3.61 3.86 3.86 3.91 4.22 3.61
0.142 0.142 0.142 0.152 0.152 0.154 0.166 0.142
0-2 0-2 0-2 0-2 0-2 0-2 0-2 4-8
0-2 0-2 0-2 0-2 0-2 0-2 0-2 4-8
0.86 1.08 1.22 1.37 1.50 1.60 1.65 0.96
0.034 0.042 0.048 0.054 0.059 0.063 0.065 0.038
6 6
1.22 1.02
0.048 0.040
3.33 0.71
0.131 0.028
3-61 0.61
0.142 0.024
4-8
4-8
—
—
1.17 0.74
0.046 0.029
6 6
1.42 0.81
0.056 0.032
0.99 2.69
0.039 0.106
0 .74 3.61
0.029 0.142
0-2
0-2
0.91 0.86
0.036 0.034
6 6 6 6 6 6 6
1.02 1.22 1.42 1.62 1.85 2.08 2.31
0.040 0.048 0.056 0.064 0.073 0.082 0.091
3.00 3.25 3.56 3.86 4.17 4.47 4.83
0 .1 1 8 ’ * 3.61 0.128* * 3.61 0.140* ‘ 3.86 3.86 0.152 0.164 3.91 0.176 4.22 0.190 4.58
0.142 0.142 0.152 0.152 0.154 0.166 0.180
0-2 0-2 0-2 0-2 0-2 0-2 0-2
0-2 0-2 0-2 0-2 0-2 0-2 0-2
1.08 1.22 1.37 1.50 1.60 1.65 1.68
0.042 0.048 0.054 0.059 0.063 0.065 0.066
6 6 6 6
1.02 1.22 1.62 2.08
0.040 0.048 0.064 0.082
3.17 3.33 3.86 4.42
0.125* * 0.131* * 0.152* * 0.174
3.61 3.61 3.86 3.86
0.142 0.142 0.152 0.152
4-8 4-8 4-8 4-8
4-8 4-8 4-8 4-9
0.96 1.17 1.45 1.63
0.038 0.046 0.057 0.064
6 6 6
1.02 1.22 1.42
0.040 0.048 0.056
3-61
0.142
6 6 6
1.02 1.22 1.42
0.040 0.048 0.056
3.61
0.142
—
—
—
___
—
—
—
___
—
—
—
___
—
___
—
___
—
—
—
—
___
___
—
—
—
—
—
0.51 0.64 0.74 0.84 0.91 1.02 1.12 1.19 1.27 1.37 1.52
0.020 0.025 0.029 0.033 0.036 0.040 0.044 0.047 0.050 0.054 0.060 0.020 0.025 0.029 0.033
* D e s ig n a te s d ia m e te r a t la rg e s t pla c e . ’ * 0.095 fo r c la s s e s 1b, 3b, 4b a n d 8 on ly .
2. Applicable Specifications and Standards 2.1 Specifications. There are no other specifi cations applicable to this specification. (Copies o f American Dental Association specifications may be obtained on application to the Council on Dental Materials and Devices, American Dental Association, 211 E Chicago Ave, Chicago, 111 60611. 2.2 Standards. The following ASTM standard o f 962 ■ JADA, Vol. 81, October 1970
the issue in effect on the date o f certification shall be made a part o f this specification: ASTM Standard D -5-52 Penetrometer Point. 3. Requirements 3.1 Construction. 3.1.1 Type I burs shall be o f the type convention ally known to the dental trade as “steel burs.”
.0919
-0700
Diameter slightly
F ig l
■
S h a n k e n d o f m a n d r e l: c la s s 1.
.052
F ig 2 ■ S h a n k e n d o f m a n d r e l: c la s s 2.
All dimensions in inches
3.1.2 Type II burs shall be of the type conven tionally known to the dental trade as “carbide burs.” 3.2 Dimensions. 3.2.1 H e ad and neck dimensions. The head and neck dimensions for all sizes of burs shall be as shown in Table 1. 3.2.2 Shank dimensions. The shank dimensions for all classes o f burs shall be as given in Table 2 and Figures 1 through 7. 3.2.2.1 In those instances where the values o f Ta ble 2 indicate maximum and minimum shank and overall lengths differing by more than 1.02 mm (0.040 inch), each manufacturer shall designate a normal design length within the limits o f Table 2. A ll bur lengths shall fall within ± 0 .5 1 mm (0.020 inch) o f the designated value as well as within the limits o f Table 2. 3.3 R unout. 3.3.1 Type I burs. The total indicated runout shall not exceed 0.08 mm (0.003 inch) when mea sured as specified in 4.2.4. 3.3.2 Type I I burs. The total indicated runout should not exceed 0.05 mm (0.002 inch) when mea sured as specified in 4.2.4. 3.4 Cu ttin g ability. The total time required for a
sample o f five burs, selected as specified in 4.1.3, to cut a distance of 0.51 mm (0.020 inch) each in brass when tested as specified in 4.3.1, shall not exceed that indicated in Table 3, column 5, for each size. 3.5 D urability. The total depth o f holes cut in glass by a sample of five burs selected as specified in 4.1.3 when tested as specified in 4.3.2, shall be no less than that indicated in Table 4 for each type and size. 3.6 B u r neck strength. N one o f a sample of five burs selected as specified in 4.1.3 shall break, nor take a permanent set o f more than 0.08 mm (0.003 inch) when tested as specified in 4.3.3. 3.7 Surface roughness. The surface roughness o f the shanks o f Class 4a, angle handpiece— friction grip instruments, Class 4b, angle handpiece— fric tion grip, short neck instruments, and Class 8, angle handpiece— miniature friction grip instruments shall not be more than a RMS value o f 20 micro-inches (root-mean-square variation 20 millionths o f an inch) when tested as specified in 4.2.5. 4.
Sampling, Inspection and Test Procedures Sampling procedures. Sampling and testing for certification shall be by type and size. A ll classes 4.1
REPORTS OF COUNCILS AND BUREAUS ■ 963
__/
Optionasl dimension
n r ■ I bmi" )S3—!I---------------J- - 1 -
Fig 3 ■ Shank end of mandrel: class 3.
Optional dimension Cmin, .003max .
OPTION OPTIONAL DIMENSION A B C D NO. All dimensions in inches
I II III
.010
_
_
-
.008 .001
.001 .001 .006-,008 -
.001- .006
May have flat end if diameter of fiat is less than 0.052 in. Angle must be 60° or less
Fig 4 ■ Shank end of mandrel: classes 4 and 8.
Rounded end no sharp edfe blend with o.d.
All dimensions In Inches Dimension
class 4a 0.400-0.545 class 4b 0.300-0.500 class 8 0.355-0.395 class 4a 0.0624-0.0631 class 4b 0.0624— 0.0631 class 8 0.0420-0.0425
Fig 5 ■ Shank end of mandrel: class 5.
All dimensions in inches
964 ■ JADA, Vol. 81, October 1970
Fig 6 ■ Shank end of mandrel: class 6.
F ig 7 ■ S h a n k e n d o f m a n d r e l: c la s s 7.
of burs o f one type and size made by one manufac turer shall be considered as a group for certification purposes and shall be accepted or rejected together. Sampling shall be done by a modified double sam pling procedure with the combined first and second samples, called a “certification sample,” being ob tained together. When five or less sizes o f one type are submitted simultaneously for certification, each size shall be sampled. When more than five sizes o f one type are submitted simultaneously, certification samples shall be obtained for five sizes chosen to be representative o f the sizes submitted. The certifica tion samples shall be selected so as to include as far as possible one sample of each class in which the burs are supplied. If each o f the certification samples test ed complies with the specification, all of the sizes submitted simultaneously shall be accepted for certi fication. If one or more o f the certification samples fails to comply with the specification, all o f the sizes submitted simultaneously shall be rejected but may
be resubmitted for certification at a later date. 4.1.1 Certification sample. A certification sam ple shall consist o f 105 burs o f one type, size, and class, as indicated by the package identification. It shall be obtained by open market procurement in at least four widely separated localities in the United States, no more than 30 burs being obtained in one place. 4.1.2 Inspection samples. A first sample o f 35 burs shall be chosen at random from the certifica tion sample and inspected in accordance with the provisions o f 4.2 for compliance with 3.1, 3.2, 3.3, 5.1, 5.2, and 5.3. If a second sample is required, the remaining 70 burs o f the certification sample shall be employed for this purpose. 4.1.3 Test samples. A sample o f five burs shall be selected at random from among the burs inspect ed as specified in 4.2, no more than one bur, how ever, being selected from any one package. Three REPORTS OF COUNCILS AND BUREAUS ■ 965
Table 2 ■ Shank dimensions. C la s s
m m. 1a 1b 2 3a 3b 4a 4b 5 6 7 8
22.22 18.41 44.45 18.79 17.39 19.17 16.25 19.05 26.16 23.62 14.09
+ 0.25 + 0.38 + 0.25 0.51 ± 0.25 ± 0.89 ± 0.64 ± 0.25 ± 0.51 ± 0.25 ± 0.51
0.875 0.725 1.750 0.740 0.685 0.755 0.640 0.750 1.030 0.930 0.555
S h ank Len ath
D ia m e te r
O v e r-a ll Length
M in. in.
m m.
in.
± ± ± ± ± ±
2.334-2.360 2.334-2.360 2.334-2.360 2.329-2.360 2.329-2.360 1.585-1.603 1.585-1.603 3.68 -3.81 3.772-3.779 2.336-2.346 1.066-1.079
0.0919-0.0929 0.0919-0.0929 0.0919-0.0929 0.0917-0.0929 0.0917-0.0929 0.0624-0.0631 0.0624-0.0631 0.145 -0.150 0.1485-0.1488 0.0920-0.0924 0.0420-0.0425
0.010 0.015 0.010 0.020 0.010 0.035 ± 0.025 ± 0.010 ± 0.020 ± 0.010 ± 0.020
Max.
mm.
in.
m m.
in.
10.66 9.14 27.94 5.321 5.321 10.16 7.62 9.39 13.56 13.18 9.01
0.420 0.360 1.100 0.2095 0.2095 0.400 0.300 0.370 0.534 0.519 0.355
13.91 13.08 35.81 5.664 5.664 13.84 12.70 9.65 13.74 13.31 10.03
0.548 0.515 1.410 0.2230 0.2230 0.545 0.500 0.380 0.541 0.524 0.395
Table 3 ■ C utting ability. S ize
Brass T h ic k n e s s
mm. 1/2 1 2 3 4 5 6 7 8 9 11 111/2 12 14 16 331/2 34 35 36 37 38 39 40 551/2 56 57 58 59 60 61 62 170 171 502 504 556 557 558 559 560 561 562 563 700 701 702 703
in.
0.28 0.28 0.28 0.28 0.51 0.51 0.51 0.51 0.51 0.51 0.51
0.011 0.011 0.011 0.011 0.020 0.020 0.020 0.020 0.020 0.020 0.020
0.28 0.28 0.28 0.28 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.28 0,51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51
0.011 0.011 0.011 0.011 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 Ö.011 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020
D epth o f s e ttin g fo r c u t* m m.
in.
P ro je c tio n o f b u r end th ro u g h brass mm.
M a xim um to ta l m illin g tim e T ype I T ype II
in.
seconds
0.38 0.46 0.56 0.71 0.86 0.96 1.08 1.17 1.32 1.42 1.68
0.015 0.018 0.022 0.028 0.034 0.038 0.042 0.046 0.052 0.056 0.066
0.10 0 .18 0.28 0.44 0.44 0.46 0.56 0.66 0.81 0.91 1.17
0.004 0.007 0.011 0.017 0.017 0.018 0.022 0.026 0.032 0.036 0.046
45 45 35 35 25 25 25 25 25 25 25
40 40 25 25 25 25 25 25 25 25 25
0.41 0.41 0.41 0.41 0.64 0.64 0.64 0.64 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 ' 1.52 0.51 0.86 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52 1.52
0.016 0.016 0.016 0.016 0.025 0.025 0.025 0.025 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.020 0.034 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060
0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 0.28 0.44 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02 1.02
0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.011 0.017 0.040 0.040 0.040 0.040 0.040 0.040 0.040 ' 0.040 0.040 0.040 0.040 0.040
120 120 100 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 35 25 50 50 50 50 50 50 50 50 50 50 50 50
25 25 25 25 50 50 50 50 50 50 50 50 50 50 50 50 50 50 25 25 50 50 50 50 50 50 50 50 50 50 50 50
• D epth o f b u r tip b e lo w s u rfa c e o f te s t s trip .
such samples shall be chosen and tested, one each for compliance with the requirements o f 3.4, 3.5, and 3.6 by the methods specified in 4.3 If the certifica tion sample fails the inspection o f 4.2, it fails the 966 ■ JADA, Vol. 81, October 1970
specification, and the tests o f 4.3 need not be per formed. 4.2 Inspection procedures. Visual inspection without magnification shall be used in determining
Table 4 ■ Durability. S iz e
Table 5 a Classification of defects by classes—major.
M in im u m to ta l deDth o f Type I mm.
V2 2 3 4 5 6 7 8 9 11
111/2 12 14 16 331/2 34 35 36 37 38 39 40 551/2 56 57 58 59 60 61 62 170 171 502 504 556 557 558 559 560 561 562 563 700 701 702 703
3.18 3.18 3.81 3.81 4.44 4.44 4.44 4.44 3.81 3.81 3.81 3.18 3.18 3.81 4.44 3.18 3.18 3.81 3.81 4.44 4.44 4.44 4.44 3.18 3.18 3.81 3.81 4.44 4.44 4.44 4.44 3.81 3.81 3.81 4.44 3.81 4.44 4.44 4.44 4.44 4.44 4.44 4.44 3.81 4.44 4.44 4.44
25 h o le s
C la ss
a
Type II in.
0.125 0.125 0.150 0.150 0.175 0.175 0.175 0.175 0.150 0.150 0.150 0.125 0.125 0.150 0.175 0.125 0.125 0.150 0.150 0.175 0.175 0.175 0.175 0.125 0.125 0.150 0.150 0.175 0.175 0.175 0.175 0.150 0.150 0.150 0.175 0.150 0.175 0.175 0.175 0.175 0.175 0.175 0.175 0.150 0.175 0.175 0.175
mm. 6.10 8.26 10.16 10.16 10.16 10.16 10.16 10.16 10.16 10.16 10.16 6.10 8.26 10.16 10.16 6.10 6.10 7.62 10.16 10.16 10.16 10.16 10.16 6.10 8.26 10.16 10.61 10.16 10.16 10.16 10.16 8.26 8.89 10.16 10.16 8.89 10.16 10.16 10.16 10.16 10.16 10.16 10.16 7.62 10.16 10.16 10.16
in. 0.240 0.325 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.240 0.325 0.400 0.400 0.240 0.240 0.300 0.400 0.400 0.400 0.400 0.400 0.240 0.325 0.400 0.400 0.400 0.400 0.400 0.400 0.325 0.350 0.400 0.400 0.350 0.400 0.400 0.400 0.400 0.400 0.400 0.400 0.300 0.400 0.400 0.400
2
3a 3b 4a 4b 5 6 7 8
D ia m e te r o f shan k e x c e e d s m a xim um in T a b le II. D -fla t d im e n s io n e x c e e d s 1.840 m m. (0.0725 in.). S h o u ld e r to g ro o v e m e a s u re m e n t le s s th a n 1.753 mm. (0.069 in .). W id th o f g ro o v e le s s th a n 0.864 m m. (0.034 in.). D ia m e te r o f g ro o v e o v e r 1.450 m m . (0.059 in.). D -fla t d im e n s io n e x c e e d s s p e c ific a tio n . S h o u ld e r to g ro o v e m e a s u re m e n t le s s th a n 5.321 m m. (0.2095 in .). W id th o f g ro o v e le s s than 0.940 m m. (0.037 in.) D ia m e te r o f g ro o v e o v e r 1.880 m m . (0.0740 in.). T a p e r a n g le o u ts id e o f 5 ° -3 ' -4 0 " —4 ° -5 3 ' -35". S h o u ld e r to g ro o v e m e a s u re m e n t m o re th a n 5.664 mm. (0. 2 230 in .).
C la s s ific a t io n o f d e fe c ts b y c la s s e s — m in o r . C lass
a
b
c
d
e
f
g
h
1a 1b
X X X X X X X X X X X
X X X X X X X X X X X
X X X X X X X
X X
X X X X X X X X X X X
X X X
X X X X X X X X X X X
X X X X X X X X X x X
2
3a 3b 4a 4b 5
6
7 8
a. b.
com pliance with the requirements of 3.1. Methods of inspection for compliance with 3.2 and 3.3 shall be as outlined below. 4.2.1 Quality level. All bur defects as deter mined by inspection shall be divided into major de fects and minor defects. Major defects shall include only those items that would prevent a bur from op erating. Minor defects shall be all other deviations from specifications that would tend to lower the quality o f the product. Acceptable quality levels shall be as follows: Type I Major defects 2.5 % defective. Minor defects 6.5% defective. Type II Major defects 1.5 % defective. Minor defects 4.0% defective. Major and minor defects for each type and class shall be as listed in Table 5. 4.2.2 C om pliance. When the number of defec tive units found in the first sample, after inspection as specified in 4.2, is equal to or less than the first
x X X X X X X X X X X
1a 1b
c. d. e. f. g. h. i. j. k.
X X X
X X
X X X
X X X X X
.
i
j
X X
X X
k
X X
X
X
X
T o ta l in d ic a te d ru n o u t e x c e e d s re q u ire m e n ts . Head d im e n s io n s o u ts id e of s p e c ific a tio n lim its w h en m e a s u re d to th e n e a re s t 0.025 m m . (0.001 in .). D ia m e te r o f sh a n k le s s than s p e c ifie d . O th e r fittin g d im e n s io n s not to s p e c ific a tio n . O v e r-a ll le n g th no t to s p e c ific a tio n . Length o f s tra ig h t shan k le s s than s p e c ifie d . N e ck d ia m e te r e x c e e d s s p e c ifie d v a lu e s . Head m is s h a p e n to e x te n t o f lo s in g id e n tity . P o or fin is h on shank. C u t-o ff on sh a n k no t as in d ic a te d in fig u re , C one a n g le on shan k o u ts id e o f s p e c ific a tio n .
acceptance number in Table 6, the certification sam ple complies. When the number o f defective units found in the first sample is equal to or greater than the first rejection number, the certification sample fails. When the number o f defective units found in the first sample is between the first acceptance and rejection numbers, a second sample shall be inspect ed. The number o f defective units found in the first and second samples shall be accumulated. If the cu mulative number o f defective units is equal to or less REPORTS OF COUNCILS AND BUREAUS ■ 967
Table 6 ■ Number of defects for acceptance and rejection. Acceptable Quality Level
1.5
2.5
4.0
6.5
Sample Sample Cumulative Ac. Re. Ac. Re. ^c. Re Ac. Re.* Size Sample Size F irs t
35
35
1
3
1
5
2
7
3
12
S e cond
70
105
2
3
4
5
6
7 11
12
* A c. = A c c e p ta n c e , Re. = R e je c tio n .
than the second acceptance number of Table 6, the certification sample complies. If the cumulative num ber o f defective units is equal to or greater than the second rejection number, the certification sample fails. 4.2.3 Dimensions. Inspection of head and shank diameters as required for all classes in 3.2 shall be made with tungsten carbide ring gauges checked reg ularly with mating plugs. The neck diameter shall be inspected with a calibrated blade-type micrometer caliper. The fitting dimensions of classes 1, 3, 5, 6, and 7 burs shall be checked with appropriate gauges with tungsten carbide faces. Overall length and other dimensions shall be checked with a standard tung sten carbide faced micrometer caliper or with a tool maker’s microscope. The toolmaker’s microscope or an optical comparator shall be used for measuring the cone angles. For a true reading of the cone angles, the reading must be made on one blade on one side o f the bur head; reading the angle by a par tial rotation o f the bur, equal to the spiral of the blade, in a vee-block. The angle so measured shall be doubled to give the cone angle. 4.2.4 R unout. The total indicated runout of the bur neck shall be measured to the nearest 0.01 mm (0.0005 inch). The bur shall be held in a vee-block or precision chuck and rotated slowly. A dial indi cator sensitive to 0.005 mm (0.0002 inch), equipped with a knife-edge foot, or other suitable equipment of equal accuracy, shall be employed. If a dial indi cator is used, it shall be mounted with the shaft per pendicular to the axis o f the bur and shall be so posi tioned that the foot contacts the bur neck at the point o f smallest diameter. The difference between the maximum and minimum dial indicator readings for one full rotation o f the bur shall be taken as the total indicated runout. 4.2.5 Surface roughness. The surface rough ness of the shanks o f instruments specified in 3.7 shall be determined by a Brush Surfindicator or equipment o f demonstrated equal quality. The sur face roughness shall be determined in the longitudi nal direction o f the straight portion o f the shank. 4.3 Test procedures. 4.3.1 C u ttin g ability.
A test sample o f five burs selected as specified in 4.1.3 shall be tested for cut ting ability as follows: 968 ■ JADA, Vol. 81, October 1970
4.3.1.1 Test material. The test material for the cutting ability test shall be 70-30 brass sheet cut to suitable size for use in the test equipment. The brass sheet shall have a Rockwell hardness o f B40-B65 and shall be o f two thicknesses: 24 and 29 B and S gauge (0.020 and 0.011 inch). The thickness o f brass used for each size bur is specified in Table 3. 4.3.1.2 Equipm ent. The equipment shall consist o f a precision chuck capable o f holding the burs to be tested, a movable carriage for the test material, and necessary accessories for measuring the time re quired to cut 0.51 mm (0.020 inch) within 0.5 second. The bur shall be positioned perpendicular to the brass test strip and the relative heights shall be ad justable so as to allow com pliance with the depth o f setting for cut as shown in Table 3. The test equip ment shall be so designed as to apply a constant 1 lb contact load between the bur and test strip, perpen dicular to the bur axis. 4.3.1.3 Procedure. A bur to be tested and a brass test strip o f the proper thickness shall be placed in the test apparatus and their relative heights adjust ed. The brass thickness, depth o f setting for cut, pro jection o f the bur end and the test load shall be made to comply with the values specified in Table 3. The bur shall be rotated at a speed o f 4350 ± 5 0 rpm and brought into contact with the edge o f the brass strip. A preliminary cut equal to at least half, but no more than one, bur diameter shall be made before making readings. The time required for the bur to cut a dis tance o f 0.51 mm (0.020 inch) shall be determined to ± 0 .5 second. 4.3.1.4 Com pliance. If the total time required for a test sample o f five burs to cut a distance o f 0.51 mm (0.020 inch) each is less than or equal to that shown in Table 3, the sample complies with the re quirement o f 3.4. If the total tim e exceeds that shown in Table 3, two more test samples o f five burs each shall be selected and tested in the same fashion. If both additional test samples comply, the certifica tion sample complies. If either fails, the certification sample fails. 4.3.2 D urability. A test sample of five burs se lected as specified in 4.1.3 shall be tested for dura bility as follows: 4.3.2.1 Test material. The test material for the durability test shall be crystal plate glass more than 3.18 mm (0.125 inch) thick having a Knoop hard ness number o f 450-510 with a 1 kg load. 4.3.2.2 Equipm ent. The equipment for the dura bility test shall consist of a true running chuck capa ble o f holding and rotating the bur being tested and a movable platform or carriage suitable for carrying the flat surface o f a glass test block into contact with the bur at an angle o f 22’/2 degrees from the axis of the bur. The machine shall be capable o f main taining a contact load of 1 lb perpendicular to the glass surface. 4.3.2.3 Procedure. A bur to be tested shall be
placed in the test apparatus and rotated at 1,550 ± 5 0 revolutions per minute. The glass test plate shall be slowly brought into contact with the bur and held in contact for a period of 2,000 revolutions. The glass plate shall then be removed so that a new portion of the flat surface is exposed to the bur for 2,000 revo lutions. Five such holes shall be made using turpen tine as a cutting fluid. The plate shall then be re moved and the depth o f the holes measured with a sharp point on a dial gauge sensitive to 0.005 mm (0.0002 inch). The point shall meet the require ments o f ASTM Standard D-5-52. 4.3.2.4 Com pliance. If the total depth o f the 25 holes cut by the five burs of the test sample equals or exceeds that specified in Table 4, the sample com plies. If the total depth of holes is less than that spe cified for the type and size of bur tested, two more test samples o f five burs each shall be chosen and tested in the same manner. If both o f these test sam ples comply, the certification sample complies. If either fails to pass, the certification sample fails. 4.3.3 N eck strength. A test sample o f five burs selected as specified in 4.1.3 shall be tested for neck strength as follows: 4.3.3.1 Equipm ent. The equipment for the neck strength test shall consist o f a suitable chuck for hold ing and rotating the bur to be tested, a loading de vice capable o f applying the designated loads through an anvil with a flat surface at an angle o f 22Vi de grees to the bur axis, and a measuring device similar to that o f 4.2.4 for measurement o f the total runout o f the bur. In the case of those classes which have shanks o f uniform diameter (Classes 1, 2, 4, and 7) the chuck shall grip at least 9.52 mm (0.375 inch) o f shank starting at the intersection o f neck and shank. All other classes o f bur shall be gripped by the chuck at all points normally gripped by the dental hand piece. 4.3.3.2 Procedure. The bur being tested shall be placed in the chuck and its total indicated runout shall be determined. The bur shall then be rotated to the position giving the highest deflection reading on the dial gauge. A load of the magnitude specified in Table 7 shall then be applied slowly at an angle o f 2 2 Vi degrees to the bur axis, in the direction which tends to increase the dial deflection reading. The load shall then be removed and the total indicated runout redetermined. 4.3.3.3 Compliance. A bur complies with this requirement if the neck does not break and if the to tal indicated runout does not increase by more than 0.08 mm (0.003 inch). If a bur breaks in the head dur ing the test, one bur per test sample may be replaced without prejudice to the results. The test sample com plies when all five burs comply individually. If the first test sample complies, the certification sample complies. If the first test sample fails, two addi tional test samples shall be chosen and tested in the same manner. If both o f these test samples comply,
Table 7 ■ Neck strength, nondamaglng test load. Size
T e s t Load
1 2 3 4 5 6 7 8 9 11 11V2 12 14 16 331/2 34 35 36
kg. 1.36 1.36 1.59 1.81 2.49 2.95 3.18 3.40 3.63 4.08 4.54 1.13 1.36 1.59 2.72 1.36 1.36 1.59 1.81
37 38 39 40 55V2 56 57 58 59 60 61 62 170 171 502 504 556 557 558 559 560 561 562 700 701 702 703
2.49 2.95 3.18 3.40 0.91 1.36 1.81 2.27 2.72 2.95 3.18 3.63 1.59 2.49 1.59 2.95 1.36 1.81 2.27 3.18 4.08 3.18 3.63 1.59 2.49 3.40 4.08
1/2
lbs. 30 30 3 5 40 5.5 6.5 7.0 7.5 80 9 0 10.0 2.5 3.0 3.5 6.0 3.0 3.0 3.5 4.0 5.5 6.5 7.0 7.5 2.0 3.0 4.0 5.0 6.0 6.5 7.0 8.0 3.5 5.5 3.5 6.5 3.0 4.0 5.0 7.0 ' 9.0 7.0 8.0 3.5 5.5 7.5 9.0
the certification sample complies. If either fails, the certification sample fails. 5. Preparation for Delivery 5.1 Packaging. Burs, other than those having corrosion-resistant shanks, shall be treated with a corrosion-preventing compound. A light rust-inhibiting oil shall be considered adequate for this purpose. Type I burs shall be packaged, six o f one type, class, and size, in a moisture resistant package. Each pack age o f six burs shall have a transparent window to render the heads o f the burs visible. Type II burs shall be packaged, either one or six per package, in suitable holders having covers with transparent w in dows. 5.2.1 L o t num bers. Each package o f burs shall be marked with a serial number, or a combination o f letters and numbers, which shall refer to the manu facturer’s records for that particular lot or batch. 5.2.2 Identification. A number, or letter, or combination thereof shall be placed on the bur pack age identifying the type, class, and size contained. REPORTS OF COUNCILS AND BUREAUS ■ 969