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Radiation safety and protection in U.S. dental hygiene programs
Radiation safety and protection in U.S. dental hygiene programs Allan G. Farman, B.D.S. Ph.D.,* Nancy Hunter, C.D.A.,** and Susan Grammer, R.D.H., M.Ed.,*** Louisville, Ky. SCHOOL
OF DENTISTRY,
UNIVERSITY
OF LOUISVILLE
A survey of radiation safety and protection measures used by programs teaching dental hygiene indicated some areas for concern. No barriers or radiation shieldings were used between operator and patient in four programs. Radiation monitoring devices were not worn by faculty operators in 16% of the programs. Fewer than half of the programs used thyroid shields for patients on a routine basis. Insufficient filtration for the kilovolt peak employed was used by 14% of the programs, and for 19% more the filtration was unknown or unspecified. Three programs used closed cones. Rectangular collimation was not used at all by 63% of the programs, and only 20% used E speed film routinely. Quality assurance for equipment maintenance and for film processing were in place at only 54% and 49% of the programs, respectively. (ORAL SURG.ORAL MED. ORAL PATHOL. 62:102-106, 1986)
M
ore than a decade has passed since John H. Barr’ presented his memorable Fixott lecture entitled “Dental Radiology: A Perspective on Priorities” before the American Academy of Dental Radiology. At that time he indicated that somehow dental radiologists had allowed the clear definition of basic technical objectives in dental radiology to escapeany “substantial attention” and that specific opportunities for well-supported action in the interests of their patients had been overlooked. The areas of neglect were detailed as including failure to develop basic technical objectives for radiographic image standardization and failure to implement methods to reduce patient exposure to radiation. In particular, the use of film with a slow emulsion speed (resulting in longer than necessaryexposures), the use of closed pointed cones (causing “completely unnecessary wholesale x-ray scattering”), and failure to implement rectangular collimation to restrict the beam area were criticized. He suggestedthat the main test of efficient use of radiation exposure would be the “ratio of information yield to the x-ray exposure it entails.” Surveys of dental radiography requirements and techniques for dental schools in 1980 and for accredited dental assisting programs in 1982 have indicated *Professor and Director of Radiology, Department of Diagnostic Sciences. **Program Assistant for Radiation Quality Administrations, Department of Diagnostic Sciences. ***Associate Professor, Dental Auxiliary Education.
102
a lack of standardization in radiography instruction in the United States.*13In addition, it was shown that many of the negative issuesin radiography highlighted by Barr’ were prevalent in the centers of learning. These particular surveys were not primarily directed at radiation safety and protection, so this aspect was only briefly explored. The aim of this article is to present the current status of radiation safety and protection at institutions providing accredited dental hygiene programs in the United States. METHODS
Questionnaires with covering explanatory letters were sent to the persons responsible for teaching radiography in U.S. accredited dental hygiene programs. Questions involved radiation safety and protection procedures for faculty operators, student operators, and patients, the equipment, materials, and exposure parameters (kilovolt peak and distance) used for intraoral radiographic techniques, and the presence or absence of quality assurance programs for equipment maintenance and film processing. Programs that did not respond to the first mailing of questionnaires were contacted a second time and, if necessary, a third time. A total of 175 replied, representing 87% of all accredited dental hygiene programs in the United States. All contacted states and Puerto Rico were represented in the replies. One reply was from a program scheduled to ceaseoperation; that response was excluded from the data
Radiation
Volume Number
62 1
Table
I. Radiation monitoring devices Dental school Devices
Faculty Film badges Ionizing chamber
*TM
Four-year
No.
I%)
No.
32 I*
(91)
25 0
college I%)
(62)
Thermoluminescent None Students
2 1
(3)
1 8
Film badges Ionizing chamber None
6 3 26
(17) (9) (74)
21 0 13
t-1 (38)
(6)
Two-year college No.
(74) t-1 (3) (24)
(3)
safety and protection
103
Total
(%‘ol
No.
(%I
84 2*
(82) (2)
141 3*
0 18
(-) (17)
3 27
(82) (2) (2) (16)
70 2 32
(68)
97 5 71
(2) (31)
(56) (3) (41)
programs used both film badges and ionizing chambers.
analysis. Comparisons were made between programs in dental schools, 4-year colleges or universities, and 2-year colleges or technical institutes. RESULTS Operator protection
Operatory shielding and radiation barrier. Barriers were present between the operator and patient in the vast majority of instances (98%). The four programs using only distance and positioning rather than barriers included two in 4-year colleges (69%) and two in 2-year colleges (29%). Radiation-monitoring deveices. Radiation-monitoring devices were worn by radiography faculty in 84% of the programs. The most common device was the film badge (82%), which was used by 91% of faculty of dental hygiene programs in dental schools, 74% in 4-year colleges, and 82% in 2-year colleges. Other devices used were pocket ionizing chambers (2%) and thermoluminescent devices (2%) (Table I). Monitoring devices were worn by student operators in 59% of the programs-film badges in 56% and pocket ionizing chambers in 3%. Film badges were worn by students in 68% of the programs in 2-year colleges and 62% of the programs in 4-year colleges. By contrast, students wore film badges in only 17% of dental hygiene programs in dental schools (Table I). Patient
protection
Lead clothing. All programs draped patients in lead aprons for dental radiographic procedures. Thyroid shields were routinely used by 84 programs (49%) and were sometimes used in a further 42 programs (24%). Twenty-seven percent of dental hygiene programs never used leaded collars to protect the thyroid gland (Table II). Kilovolt peak. High kilovolt peak (kVp) tech-
Table
It. Thyroid shield use Routine
Sometimes
Never
Program
No.
(%)
No.
(%)
No.
(W)
Dental school Four-year college Two-year college
17 17 50 84
(49)
I5 7 20 42
(43) (21) (19) (24)
3 10 21 46
(9) (29) (32)
TOTAL
(50) (49) (49)
(27)
niques were used for periapical radiographs in 1I5 programs (69%) and for bitewings in ninety-one programs (55%). Only one program in a 2-year college used a kilovolt peak of less than 60 (56 kVp). Potentials of 60 to 79 kVp were used by 30% of the programs for periapical radiographs and by 45% of the programs for bitewing radiographs (Table III). Six respondentsconfused kilovolt peak with milliampere and answered “10” or “15.” Filtration. Based on guideline figures of 2.5 mm aluminum equivalence minimum filtration for 70 kVp and above and 1.5 mm aluminum equivalence for less than 70 kVp, at least twenty-four programs (14%) were reportedly using insufficient filtration: five programs (14%) in dental schools, fifteen programs (15%) in 2-year colleges, and four programs (12%) in 4-year colleges. The filtration equivalence either was not specified or was indicated as unknown by thirty-two programs (19%). “Cone” type. The programs using and emphasizing each type of “cone” are listed in Table IV. By far the most common types were open-ended, but three programs used enclosed plastic pointed cones. However, two of these three programs indicated that this type of cone was used only for working with manikins during preclinical laboratories in intraoral dental radiographic techniques. Cone length used is indicated in Table V. The most frequently used type was the long cone; 81
104
Farman, Hunter, and Grammer
Table
III. Kilovoltage used for radiography
Oral Surg. July, 19%
..-
Dental school Kilovolt
peak
No.
’
Four-year
college
Two-year college
(%I
No.
(%)
No.
(“roi
No.
---. iSI
19
(68)
56
(56) (44)
23
80+ <60-79 60
11
(32)
13 24
(74) (24)
II5 50
(69) (30)
0
t-1
0
t-1
1
(1)
I
(1)
Bitewings
12
80+ 60-79 <60
22
(35) (65)
17 17
(50) (50)
62 35
(63) (36)
91 14
(55) (45)
(-)
0
C-1
0
1
(1)
Dental school “Cone” type
No.
Circular lead lined Circular clear plastic Rectangular Enclosed plastic pointed
32 15
Some
programs
“cones”
Table V.
1
Dental school
Four-year college
(1)
“Cone” type Dental hygiene program
*Pointed
\
Periapicals
Table IV.
NOTE:
Total
8
I*
Four-year college
with
Total
(W)
No.
(W)
No.
(%)
No.
(%)
No.
(91)
33 15 6
(94) (44) (18)
95 25 26
(92)
160 55 40
(93) (32) (23)
28
(24) (25)
1
(3)
(43) (23) (3)
used or emphasized
used only
Main emphasis
Two-year college
more
than
one type
1*
(1)
3
(2)
(%)
630)
7 6
(20) (17)
0
(-)
Two-year college
Total
No.
(%)
No.
(%)
No.
(%)
30 6 3
(86) (18)
88 9
(85)
(9) (3)
11 0
(11) C-1
146 22 20
(85) (13) (12)
1
(9)
1
(1)
of “cone.”
manikins.
“Cone” length Dental hygiene program using Dental school
“Cone” length
No.
(%I
Short ((12 in.) only Long (‘r 12 in.) only Both long and short
3 24 8
(6%
(9) (23)
Four-year
college
Two-year college
No.
(%l
No.
(%I
1
(3) (47) (50)
8 41 54
(40)
16 17
programs (47%) used long cones only, and 79 programs (46%) used both long and short cones. Short cones alone were restricted to 12 programs (7%). Six 2-year colleges and two dental school dental hygiene programs used only short cones but professed to giving preference to the paralleling technique for intraoral radiographic surveys. Film-holding devices. All programs used at least one film-holding device irrespective of whether they also occasionally resorted to patients holding the film in their mouths with their fingers. Of the filmholding devices (Table VI), the Rinn XCP instrument was the most popular (90%); its use was emphasized by 83% of respondents. The Snap-a-Ray device was the next most commonly used (80%); its use was emphasized in only 6% of the programs. Stabe disposable Styrofoam holders were used by
(8) (52)
Total No.
i%)
12 81 19
(7) (47) (46)
105 programs (61%) and were emphasized by twenty-seven programs (16%). Although 32% of the programs taught the use of the patient’s finger as a film-holding device, only 2% placed emphasis on this method. Rectangular collimation. Rectangular collimation using either rectangular “cones” or Precision filmholding devices was used by 64 programs (37%). Theseincluded 14in dental schools(40%)) 10in 4-year colleges (29%)) and 40 in 2-year colleges (39%). Film speed. Film speed chosen by the responding programs is shown in Table VII. Only thirty-five programs (20%) used E-speed film exclusively. Eighteen others (10%) used both E and D speeds. Exclusive use of D-speed film was most common in 2-year colleges (74%). Number ofjilms in intraoral surveys. The number
Radiation safety and protection
Volume 62 Number 1
105
Table VI. Film-holding device in use Dental hygiene program using Dental school Device
NOTE:
Some
programs
Rinn
Corp.-Elgin
Co.,
Inc.,
Two-year college
(%)
No.
f%)
No.
(W)
No.
28 19 16 8 11 8 l-2
(80) (54) (46) (23) (31) (23) (56)
34 34 17 13 7 5 l-4
(100) (100) (50) (38) (21) (15) (~12)
92 85 72 34 19 12 2-8
(89) (83) (70) (33) (18)
154 138 105 55 37 25 1-13
-
-
used or emphasized Div.,
Elgin,
more
(14 (~5) -
than
III. Snap-a-Ray,
one type ADA
Dental school
Total
No.
xcp* Snap-a-Ray* Stabe* Patient’s finger Precision* Hemostat Other None ‘XCP,
Four-year college
Main emphasis
of film-holding Inc.,
Two-year college
Total
(96)
No.
(%)
No.
(%)
No.
(%)
No.
(%)
(90)
21 4 5
(60) (11) (14) (3) (17) (3) t-j (3)
20 1 1 0 ;
(59) (3) (3) C-1 ,!?;
(43)
(3) (32)
85 11 27 4 7 1 3 40
(83)
1:
44 6 21 3 0 0 2 28
(8’3) (61) (32)
(22)
A
(15) (‘8)
iJ
-
Products,
Four-year college
1
(6) (20) (3) C-1 C-1 (2) (27)
(‘4 (16)
(2) (4) (1)
(2) (23)
device. Milwaukee.
@abe,
Cook-Waite
Laboratories.
Inc.,
New
York.
Precision,
Masel
Philadelphia.
Table VII. Film speed Dental school
Four-year
college
Two-year college
Total
Film speed
No.
(“r,)
No.
(%I
No.
(%I
No.
f%)
Ultraspeed only (D) Ektaspeed only (E) Both D and E
21 8 6
(60)
22 9 3
(65)
(26)
76 18 9
(74) (17) (9)
119 35 18
(20)
(23) (17)
(9)
(69) (10)
Table VIII. Number of films used for complete mouth radiographic surveys Four-year
Dental school Number of films Adult dentulous series >20 18-20
14 IO-14
Panoramic only Not taken Mixed dentition series >I4 10-14I4 IO-14
Some
programs
failed
No.
I%)
No.
3 29 2
(13) (85)
5 19 0
5 12 1 13 0
(16)
(6) (39) (3) (42) t-1
7 19 4
(23)
(61) (13) (3) t-1
1 0
(4) (1%
1
4 16 5 0
to specify
(62) (19) t-1 that
percentages
college f%)
(1% (85) t-1
9 16 2 2 3
(28)
6 24 0 0 2
(19) (75) t-J t-1
0 12 14 0 5
(39) (45) t-1
had been calculated
of films constituting an average full-mouth intraoral radiographic survey is indicated in Table VIII for adult dentulous series, adult edentulous series, mixed-dentition series, and preschool child series.
(50) (6) (6) (9)
(6)
C-J
(16) on the basis of number
Two-year college No.
8 88 6 I7 52 1
3 7
Total
(%I
No.
(%I
(8) (86) (6)
16 146 8
(86)
(21)
31 80 4 18
(65) (1) (4) (9)
8
(8) (67) (7) t-1 (18)
0 40 29 2 29
C-1
I
(40) (29)
56 59 7 34
of responses
(4 received
(5)
(22) (56) (3) (13) (7)
10
67 7 0 18
(29)
(9)
21
(13) (67) (7) (1)
110 I1 1
(12)
20
for individual
(1) (36) (38) (4)
(22) items.
For adult dentulous surveys the mode was 18 to 20 films for all programs (86%); the range was 14 to 25 films. For adult edentulous surveys the range was 2 to 2 1 films; the mode in 2- and 4-year colleges was 10
106
FaPman, Hunter, and Grammer
to 14 films, whereas the mode for dental schools was panoramic dental radiographs. For mixed dentition surveys the range was 4 to 20 films, and the mode was 10 to 14 films for all institutions. For preschool surveys the mode was 4 to 8 films in dental school dental hygiene programs, six to eight films in 4-year colleges, and ten to twelve films in 2-year colleges. Quality assurance. Programs in quality assurance for equipment maintenance were in existence for 92 dental hygiene programs. This included 44 in 2-year colleges (43%), 25 in 4-year colleges (74%), and 23 in dental schools (66%). Programs in darkroom quality assurance were used by eighty four dental hygiene programs (49%), including 23 in dental schools (66%), 20 in 4-year colleges (59%), and 41 in 2-year colleges (40%). DISCUSSION
The quality of dental radiographic surveys provided by dental health professionals is likely to be greatly influenced by the quality of the role model provided by the respective teaching centers. Regarding radiography facilities in accredited dental hygiene programs in the United States, it appears that the present status quo is far from desirable in many instances. The use of closed pointed plastic cones is indefensible, even if they were used only on manikins in two of the three programs reporting their use. The role model is still established, inappropriately suggesting approbation of this method, when open-ended cones are readily available to convert old machines to modern standards. Another finding of concern regarding the present report was the apparent ignorance of some of the responding radiography faculty. This can be illustrated by the six instances in which kilovolt peak technique was confused with milliamperage. Regarding tube potential, it is certainly possible to reduce patient exposure by using a high kilovolt peak technique; however, when this is done, the appropriate level of filtration should be applied. It is lamentable that, according to the reported data, at least 14% of the programs forgot to upgrade filtration
Oral Surg. July. 1986
when using high kilovolt peak techniques. It is also surprising that a high proportion of radiography faculty members specified that they were uncertain as to the amount of filtration currently in use in the dental x-ray machines under their control. There is a need for better training of dental radiography faculty in some dental hygiene programs. It appears that dental hygiene programs have learned little from Barr’s’ words of wisdom. Much still remains to be achieved in improving the benefits-versus-risks ratio for patients. Appropriate changes would be the development of quality assurance programs and the usageof E-speed film, thyroid shields, rectangular collimation, and long-cone techniques for the paralleling method of intraoral radiography. Barely achieving minimum legal standards should be considered insufficient for learning institutions. CONCLUSIONS
Many dental hygiene radiography facilities in the United States need upgrading. Available methods for reducing patient exposure to ionizing radiation are not being fully implemented. Training in radiation safety and protection and quality assurance is urgently needed by many dental hygiene radiography faculty members. We thank Ruth Heinz for secretarial assistance in the preparation of this manuscript. REFERENCES Barr JH: Dental radiology: A perspective on priorities. ORAL SURF ORAL MED ORAL PATHOL 34: 672-679,
I97 I.
Farman AC, Shawkat AH: Survey of radiographic requirements and techniques. J Dent Educ 45: 581-584, 1981. Farman AC, Grammar S, Hunter N, Baker C: Survey of radiographic requirements and techniques in U.S. dental assisting programs, 1982. ORAL SURC ORAL MED ORAL PATHOL 56: 430-436,
1983.
Reprint requests to: Dr. Allan G. Farman Department of Diagnostic Sciences: Radiology School of Dentistry University of Louisville Louisville, KY 40292
OF DENTISTRY,
UNIVERSITY
OF LOUISVILLE
A survey of radiation safety and protection measures used by programs teaching dental hygiene indicated some areas for concern. No barriers or radiation shieldings were used between operator and patient in four programs. Radiation monitoring devices were not worn by faculty operators in 16% of the programs. Fewer than half of the programs used thyroid shields for patients on a routine basis. Insufficient filtration for the kilovolt peak employed was used by 14% of the programs, and for 19% more the filtration was unknown or unspecified. Three programs used closed cones. Rectangular collimation was not used at all by 63% of the programs, and only 20% used E speed film routinely. Quality assurance for equipment maintenance and for film processing were in place at only 54% and 49% of the programs, respectively. (ORAL SURG.ORAL MED. ORAL PATHOL. 62:102-106, 1986)
M
ore than a decade has passed since John H. Barr’ presented his memorable Fixott lecture entitled “Dental Radiology: A Perspective on Priorities” before the American Academy of Dental Radiology. At that time he indicated that somehow dental radiologists had allowed the clear definition of basic technical objectives in dental radiology to escapeany “substantial attention” and that specific opportunities for well-supported action in the interests of their patients had been overlooked. The areas of neglect were detailed as including failure to develop basic technical objectives for radiographic image standardization and failure to implement methods to reduce patient exposure to radiation. In particular, the use of film with a slow emulsion speed (resulting in longer than necessaryexposures), the use of closed pointed cones (causing “completely unnecessary wholesale x-ray scattering”), and failure to implement rectangular collimation to restrict the beam area were criticized. He suggestedthat the main test of efficient use of radiation exposure would be the “ratio of information yield to the x-ray exposure it entails.” Surveys of dental radiography requirements and techniques for dental schools in 1980 and for accredited dental assisting programs in 1982 have indicated *Professor and Director of Radiology, Department of Diagnostic Sciences. **Program Assistant for Radiation Quality Administrations, Department of Diagnostic Sciences. ***Associate Professor, Dental Auxiliary Education.
102
a lack of standardization in radiography instruction in the United States.*13In addition, it was shown that many of the negative issuesin radiography highlighted by Barr’ were prevalent in the centers of learning. These particular surveys were not primarily directed at radiation safety and protection, so this aspect was only briefly explored. The aim of this article is to present the current status of radiation safety and protection at institutions providing accredited dental hygiene programs in the United States. METHODS
Questionnaires with covering explanatory letters were sent to the persons responsible for teaching radiography in U.S. accredited dental hygiene programs. Questions involved radiation safety and protection procedures for faculty operators, student operators, and patients, the equipment, materials, and exposure parameters (kilovolt peak and distance) used for intraoral radiographic techniques, and the presence or absence of quality assurance programs for equipment maintenance and film processing. Programs that did not respond to the first mailing of questionnaires were contacted a second time and, if necessary, a third time. A total of 175 replied, representing 87% of all accredited dental hygiene programs in the United States. All contacted states and Puerto Rico were represented in the replies. One reply was from a program scheduled to ceaseoperation; that response was excluded from the data
Radiation
Volume Number
62 1
Table
I. Radiation monitoring devices Dental school Devices
Faculty Film badges Ionizing chamber
*TM
Four-year
No.
I%)
No.
32 I*
(91)
25 0
college I%)
(62)
Thermoluminescent None Students
2 1
(3)
1 8
Film badges Ionizing chamber None
6 3 26
(17) (9) (74)
21 0 13
t-1 (38)
(6)
Two-year college No.
(74) t-1 (3) (24)
(3)
safety and protection
103
Total
(%‘ol
No.
(%I
84 2*
(82) (2)
141 3*
0 18
(-) (17)
3 27
(82) (2) (2) (16)
70 2 32
(68)
97 5 71
(2) (31)
(56) (3) (41)
programs used both film badges and ionizing chambers.
analysis. Comparisons were made between programs in dental schools, 4-year colleges or universities, and 2-year colleges or technical institutes. RESULTS Operator protection
Operatory shielding and radiation barrier. Barriers were present between the operator and patient in the vast majority of instances (98%). The four programs using only distance and positioning rather than barriers included two in 4-year colleges (69%) and two in 2-year colleges (29%). Radiation-monitoring deveices. Radiation-monitoring devices were worn by radiography faculty in 84% of the programs. The most common device was the film badge (82%), which was used by 91% of faculty of dental hygiene programs in dental schools, 74% in 4-year colleges, and 82% in 2-year colleges. Other devices used were pocket ionizing chambers (2%) and thermoluminescent devices (2%) (Table I). Monitoring devices were worn by student operators in 59% of the programs-film badges in 56% and pocket ionizing chambers in 3%. Film badges were worn by students in 68% of the programs in 2-year colleges and 62% of the programs in 4-year colleges. By contrast, students wore film badges in only 17% of dental hygiene programs in dental schools (Table I). Patient
protection
Lead clothing. All programs draped patients in lead aprons for dental radiographic procedures. Thyroid shields were routinely used by 84 programs (49%) and were sometimes used in a further 42 programs (24%). Twenty-seven percent of dental hygiene programs never used leaded collars to protect the thyroid gland (Table II). Kilovolt peak. High kilovolt peak (kVp) tech-
Table
It. Thyroid shield use Routine
Sometimes
Never
Program
No.
(%)
No.
(%)
No.
(W)
Dental school Four-year college Two-year college
17 17 50 84
(49)
I5 7 20 42
(43) (21) (19) (24)
3 10 21 46
(9) (29) (32)
TOTAL
(50) (49) (49)
(27)
niques were used for periapical radiographs in 1I5 programs (69%) and for bitewings in ninety-one programs (55%). Only one program in a 2-year college used a kilovolt peak of less than 60 (56 kVp). Potentials of 60 to 79 kVp were used by 30% of the programs for periapical radiographs and by 45% of the programs for bitewing radiographs (Table III). Six respondentsconfused kilovolt peak with milliampere and answered “10” or “15.” Filtration. Based on guideline figures of 2.5 mm aluminum equivalence minimum filtration for 70 kVp and above and 1.5 mm aluminum equivalence for less than 70 kVp, at least twenty-four programs (14%) were reportedly using insufficient filtration: five programs (14%) in dental schools, fifteen programs (15%) in 2-year colleges, and four programs (12%) in 4-year colleges. The filtration equivalence either was not specified or was indicated as unknown by thirty-two programs (19%). “Cone” type. The programs using and emphasizing each type of “cone” are listed in Table IV. By far the most common types were open-ended, but three programs used enclosed plastic pointed cones. However, two of these three programs indicated that this type of cone was used only for working with manikins during preclinical laboratories in intraoral dental radiographic techniques. Cone length used is indicated in Table V. The most frequently used type was the long cone; 81
104
Farman, Hunter, and Grammer
Table
III. Kilovoltage used for radiography
Oral Surg. July, 19%
..-
Dental school Kilovolt
peak
No.
’
Four-year
college
Two-year college
(%I
No.
(%)
No.
(“roi
No.
---. iSI
19
(68)
56
(56) (44)
23
80+ <60-79 60
11
(32)
13 24
(74) (24)
II5 50
(69) (30)
0
t-1
0
t-1
1
(1)
I
(1)
Bitewings
12
80+ 60-79 <60
22
(35) (65)
17 17
(50) (50)
62 35
(63) (36)
91 14
(55) (45)
(-)
0
C-1
0
1
(1)
Dental school “Cone” type
No.
Circular lead lined Circular clear plastic Rectangular Enclosed plastic pointed
32 15
Some
programs
“cones”
Table V.
1
Dental school
Four-year college
(1)
“Cone” type Dental hygiene program
*Pointed
\
Periapicals
Table IV.
NOTE:
Total
8
I*
Four-year college
with
Total
(W)
No.
(W)
No.
(%)
No.
(%)
No.
(91)
33 15 6
(94) (44) (18)
95 25 26
(92)
160 55 40
(93) (32) (23)
28
(24) (25)
1
(3)
(43) (23) (3)
used or emphasized
used only
Main emphasis
Two-year college
more
than
one type
1*
(1)
3
(2)
(%)
630)
7 6
(20) (17)
0
(-)
Two-year college
Total
No.
(%)
No.
(%)
No.
(%)
30 6 3
(86) (18)
88 9
(85)
(9) (3)
11 0
(11) C-1
146 22 20
(85) (13) (12)
1
(9)
1
(1)
of “cone.”
manikins.
“Cone” length Dental hygiene program using Dental school
“Cone” length
No.
(%I
Short ((12 in.) only Long (‘r 12 in.) only Both long and short
3 24 8
(6%
(9) (23)
Four-year
college
Two-year college
No.
(%l
No.
(%I
1
(3) (47) (50)
8 41 54
(40)
16 17
programs (47%) used long cones only, and 79 programs (46%) used both long and short cones. Short cones alone were restricted to 12 programs (7%). Six 2-year colleges and two dental school dental hygiene programs used only short cones but professed to giving preference to the paralleling technique for intraoral radiographic surveys. Film-holding devices. All programs used at least one film-holding device irrespective of whether they also occasionally resorted to patients holding the film in their mouths with their fingers. Of the filmholding devices (Table VI), the Rinn XCP instrument was the most popular (90%); its use was emphasized by 83% of respondents. The Snap-a-Ray device was the next most commonly used (80%); its use was emphasized in only 6% of the programs. Stabe disposable Styrofoam holders were used by
(8) (52)
Total No.
i%)
12 81 19
(7) (47) (46)
105 programs (61%) and were emphasized by twenty-seven programs (16%). Although 32% of the programs taught the use of the patient’s finger as a film-holding device, only 2% placed emphasis on this method. Rectangular collimation. Rectangular collimation using either rectangular “cones” or Precision filmholding devices was used by 64 programs (37%). Theseincluded 14in dental schools(40%)) 10in 4-year colleges (29%)) and 40 in 2-year colleges (39%). Film speed. Film speed chosen by the responding programs is shown in Table VII. Only thirty-five programs (20%) used E-speed film exclusively. Eighteen others (10%) used both E and D speeds. Exclusive use of D-speed film was most common in 2-year colleges (74%). Number ofjilms in intraoral surveys. The number
Radiation safety and protection
Volume 62 Number 1
105
Table VI. Film-holding device in use Dental hygiene program using Dental school Device
NOTE:
Some
programs
Rinn
Corp.-Elgin
Co.,
Inc.,
Two-year college
(%)
No.
f%)
No.
(W)
No.
28 19 16 8 11 8 l-2
(80) (54) (46) (23) (31) (23) (56)
34 34 17 13 7 5 l-4
(100) (100) (50) (38) (21) (15) (~12)
92 85 72 34 19 12 2-8
(89) (83) (70) (33) (18)
154 138 105 55 37 25 1-13
-
-
used or emphasized Div.,
Elgin,
more
(14 (~5) -
than
III. Snap-a-Ray,
one type ADA
Dental school
Total
No.
xcp* Snap-a-Ray* Stabe* Patient’s finger Precision* Hemostat Other None ‘XCP,
Four-year college
Main emphasis
of film-holding Inc.,
Two-year college
Total
(96)
No.
(%)
No.
(%)
No.
(%)
No.
(%)
(90)
21 4 5
(60) (11) (14) (3) (17) (3) t-j (3)
20 1 1 0 ;
(59) (3) (3) C-1 ,!?;
(43)
(3) (32)
85 11 27 4 7 1 3 40
(83)
1:
44 6 21 3 0 0 2 28
(8’3) (61) (32)
(22)
A
(15) (‘8)
iJ
-
Products,
Four-year college
1
(6) (20) (3) C-1 C-1 (2) (27)
(‘4 (16)
(2) (4) (1)
(2) (23)
device. Milwaukee.
@abe,
Cook-Waite
Laboratories.
Inc.,
New
York.
Precision,
Masel
Philadelphia.
Table VII. Film speed Dental school
Four-year
college
Two-year college
Total
Film speed
No.
(“r,)
No.
(%I
No.
(%I
No.
f%)
Ultraspeed only (D) Ektaspeed only (E) Both D and E
21 8 6
(60)
22 9 3
(65)
(26)
76 18 9
(74) (17) (9)
119 35 18
(20)
(23) (17)
(9)
(69) (10)
Table VIII. Number of films used for complete mouth radiographic surveys Four-year
Dental school Number of films Adult dentulous series >20 18-20
Panoramic only Not taken Mixed dentition series >I4 10-14
Some
programs
failed
No.
I%)
No.
3 29 2
(13) (85)
5 19 0
5 12 1 13 0
(16)
(6) (39) (3) (42) t-1
7 19 4
(23)
(61) (13) (3) t-1
1 0
(4) (1%
1
4 16 5 0
to specify
(62) (19) t-1 that
percentages
college f%)
(1% (85) t-1
9 16 2 2 3
(28)
6 24 0 0 2
(19) (75) t-J t-1
0 12 14 0 5
(39) (45) t-1
had been calculated
of films constituting an average full-mouth intraoral radiographic survey is indicated in Table VIII for adult dentulous series, adult edentulous series, mixed-dentition series, and preschool child series.
(50) (6) (6) (9)
(6)
C-J
(16) on the basis of number
Two-year college No.
8 88 6 I7 52 1
3 7
Total
(%I
No.
(%I
(8) (86) (6)
16 146 8
(86)
(21)
31 80 4 18
(65) (1) (4) (9)
8
(8) (67) (7) t-1 (18)
0 40 29 2 29
C-1
I
(40) (29)
56 59 7 34
of responses
(4 received
(5)
(22) (56) (3) (13) (7)
10
67 7 0 18
(29)
(9)
21
(13) (67) (7) (1)
110 I1 1
(12)
20
for individual
(1) (36) (38) (4)
(22) items.
For adult dentulous surveys the mode was 18 to 20 films for all programs (86%); the range was 14 to 25 films. For adult edentulous surveys the range was 2 to 2 1 films; the mode in 2- and 4-year colleges was 10
106
FaPman, Hunter, and Grammer
to 14 films, whereas the mode for dental schools was panoramic dental radiographs. For mixed dentition surveys the range was 4 to 20 films, and the mode was 10 to 14 films for all institutions. For preschool surveys the mode was 4 to 8 films in dental school dental hygiene programs, six to eight films in 4-year colleges, and ten to twelve films in 2-year colleges. Quality assurance. Programs in quality assurance for equipment maintenance were in existence for 92 dental hygiene programs. This included 44 in 2-year colleges (43%), 25 in 4-year colleges (74%), and 23 in dental schools (66%). Programs in darkroom quality assurance were used by eighty four dental hygiene programs (49%), including 23 in dental schools (66%), 20 in 4-year colleges (59%), and 41 in 2-year colleges (40%). DISCUSSION
The quality of dental radiographic surveys provided by dental health professionals is likely to be greatly influenced by the quality of the role model provided by the respective teaching centers. Regarding radiography facilities in accredited dental hygiene programs in the United States, it appears that the present status quo is far from desirable in many instances. The use of closed pointed plastic cones is indefensible, even if they were used only on manikins in two of the three programs reporting their use. The role model is still established, inappropriately suggesting approbation of this method, when open-ended cones are readily available to convert old machines to modern standards. Another finding of concern regarding the present report was the apparent ignorance of some of the responding radiography faculty. This can be illustrated by the six instances in which kilovolt peak technique was confused with milliamperage. Regarding tube potential, it is certainly possible to reduce patient exposure by using a high kilovolt peak technique; however, when this is done, the appropriate level of filtration should be applied. It is lamentable that, according to the reported data, at least 14% of the programs forgot to upgrade filtration
Oral Surg. July. 1986
when using high kilovolt peak techniques. It is also surprising that a high proportion of radiography faculty members specified that they were uncertain as to the amount of filtration currently in use in the dental x-ray machines under their control. There is a need for better training of dental radiography faculty in some dental hygiene programs. It appears that dental hygiene programs have learned little from Barr’s’ words of wisdom. Much still remains to be achieved in improving the benefits-versus-risks ratio for patients. Appropriate changes would be the development of quality assurance programs and the usageof E-speed film, thyroid shields, rectangular collimation, and long-cone techniques for the paralleling method of intraoral radiography. Barely achieving minimum legal standards should be considered insufficient for learning institutions. CONCLUSIONS
Many dental hygiene radiography facilities in the United States need upgrading. Available methods for reducing patient exposure to ionizing radiation are not being fully implemented. Training in radiation safety and protection and quality assurance is urgently needed by many dental hygiene radiography faculty members. We thank Ruth Heinz for secretarial assistance in the preparation of this manuscript. REFERENCES Barr JH: Dental radiology: A perspective on priorities. ORAL SURF ORAL MED ORAL PATHOL 34: 672-679,
I97 I.
Farman AC, Shawkat AH: Survey of radiographic requirements and techniques. J Dent Educ 45: 581-584, 1981. Farman AC, Grammar S, Hunter N, Baker C: Survey of radiographic requirements and techniques in U.S. dental assisting programs, 1982. ORAL SURC ORAL MED ORAL PATHOL 56: 430-436,
1983.
Reprint requests to: Dr. Allan G. Farman Department of Diagnostic Sciences: Radiology School of Dentistry University of Louisville Louisville, KY 40292