|Year : 2013 | Volume
| Issue : 3 | Page : 104-110
Compliance of Indian dentists with oral radiology safety measures
Swarna Yerebairapura Math1, Devarasa Giriyapura Murugeshappa2, Rajeshwari Annigeri1, Dheeraj Kalra3
1 Oral Medicine and Radiology, College of Dental Sciences, Pavilion Road, Davangere, Karnataka, India
2 Pediatric Dentistry, Faculty of Dentistry, MAHSA University, Kuala Lumpur, Malaysia
3 Public Health Dentistry Sinhgad Dental College and Hospital, Pune, India
|Date of Web Publication||7-Feb-2014|
Swarna Yerebairapura Math
Dental Radiology, Faculty of Dentistry, Mahsa University, Damansara Heights, Kuala Lumpur, Malaysia
Source of Support: None, Conflict of Interest: None
Objectives: The aim of this study was to determine the dentist's knowledge and practice about dose reduction techniques, radiographic equipment and quality of dental radiographic service among private dental practitioners in Davangere City, India. Materials and Methods: The survey was performed on 80 dental practitioners from Davangere City, India. Information on the demographic characteristics of the dentists, radiographic equipment, techniques and processing they used and radiation protection was obtained with a 40 point questionnaire. Results: The study yielded a response rate of 90%. The respondents' knowledge concerning the technical details of their equipment was limited, with 27.7% not knowing kVp settings of their equipment. Only 11% and 5% respondents reported having long and rectangular collimators respectively. Regarding the film speed 16.6% dental practitioners were unaware about it. The most preferred technique (81%) for periapical radiography was the bisecting angle technique. Lead aprons were worn more often by female dentists. None of the dental practitioners had thyroid collars. The distance of the dentist to the radiation tube during exposure was on average 2.2 m, although 13% of the dentists assisted in holding the image receptor inside the patient's mouth. Only 4% of the dental practitioners reported that they used automatic processor. About 40% of the dental practitioners used film badges. Conclusions: In the present study, the results indicate that for minimizing any unnecessary radiation, attempts should be made to improve dentists' knowledge about radiation dose reduction techniques. Some dose-reducing strategies are commonly used in Davangere Dental clinics, whereas others have not gained wide acceptance.
Keywords: Private practitioners, questionnaire survey, radiation, safety measures
|How to cite this article:|
Math SY, Murugeshappa DG, Annigeri R, Kalra D. Compliance of Indian dentists with oral radiology safety measures. J Oral Maxillofac Radiol 2013;1:104-10
|How to cite this URL:|
Math SY, Murugeshappa DG, Annigeri R, Kalra D. Compliance of Indian dentists with oral radiology safety measures. J Oral Maxillofac Radiol [serial online] 2013 [cited 2020 Jan 28];1:104-10. Available from: http://www.joomr.org/text.asp?2013/1/3/104/126744
| Introduction|| |
The radiographic examination is one of the principal diagnostic methods used in all fields of medical services and contributes to the promotion of the health, both individually and nationally. Radiographic examination plays an essential part of dental practice. Because a certain amount of radiation is inevitably delivered to patients, it should be as low as reasonably achievable (ALARA). ,
Radiation protection of patients in dental radiology is achieved in three ways: By appropriate selection criteria for patients and equipment, methods of dose limitation and quality assurance procedures.  Even if it could be assumed that radiation dose levels in dental practice are relatively low, one should consider the cumulative effect of repeated exposures. There should be a striving for the implementation of proper decision and selection criteria for radiography in private dental clinics and for radiological quality assurance. 
Though widely accepted selection criteria are lacking, there is general agreement about the methods to reduce radiation dose. Despite this, numerous surveys have concluded that patients are subjected to unnecessary radiation exposure during dental radiography.  This can occur when the X-ray equipment does not meet accepted standards, outdated techniques are used or film processing is inadequate. The choice of E-speed, instead of D-speed films and collimation of the X-ray beam to the film-size, instead of a round beam with a 6 cm diameter, are the most important measures to reduce the effective dose. 
The aim of the present survey was to determine to what extent dentists in Davangere comply with commonly accepted measures to reduce radiation dose to patients as well for the operators.
| Materials and Methods|| |
The survey was performed on 80 dental practitioners from Davangere City, India. A questionnaire consisting of 40 questions (see Appendix 1) [Additional file 1] were prepared with the following sections:
- Demographic characteristics
- Radiographic equipment and techniques
- Method of the patient and personnel protection
- Processing and Interpretation methods.
A written questionnaire was distributed by visiting each dental clinic among 80 private dental practitioners. Dentists were assured about the anonymous processing of the questionnaire, explaining the purpose of the research. A second follow-up was carried out to collect the completed questionnaire.
The resulting data was coded and statistical analysis was evaluated using SPSS (Statistical package for social sciences) software Version 17.0; Chicago, IL, USA. Mean was calculated for demographic variables and percentages were calculated for the responses given by dentists. Data was evaluated according to the frequency distribution and the significance of differences between two independent groups was determined using the Chi-squared test.
| Results|| |
The study yielded a response rate of 90%.
Profile of respondents
Among the 72 respondents, 61 were male and 11 were female dentists. 50% of the respondents were below 35 years and 50% were above 35 years of age. Of the 72 respondents, 57% identified themselves as non-specialist and 43% as specialist.
Maintenance of the radiographic equipment
Only 57% dentists reported that their X-ray units had been serviced routinely.
Characteristics of the radiographic equipment
The respondents' knowledge concerning the technical details of their equipment was limited, with (33%, 27.7% and 45%) not knowing the tube current, tube voltage and the amount of filtration of their machine respectively). As well, it was worrying that 18.5% of the dental practitioners did use their equipment set at <65 kVp.
Only 5% of the dental practitioners [Figure 1] used the rectangular radiation tube or rectangular collimator for a round radiation tube, whereas 11% used the long cone [Figure 2]. Long cone was the most preferred cone type among younger dentists (16.6%). A statistically significant difference was found between the cone type and age (P = 0.042 S). Among the observed general practitioners and specialists, the specialists preferred the long cone, which was statistically highly significant (P = 0.000 HS).
|Figure 1: The type of collimator used by Davangere private practitioners|
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|Figure 2: The length of collimator used by Davangere private practitioners|
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Nearly 86% of the practitioners preferred the conventional radiographs in which, most of them used higher speed classes (E speed: 74% or F speed: 2%), with only 4% of the respondents still using the slow D-speed film and 16% did not know the speed of the film they used [Figure 3]. Only 14% dentists replied that they had digital radiography.
|Figure 3: The Speed of film used by Davangere private practitioners graph|
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On an average, every dental practitioner exposed 20-40 intraoral radiographs every month. The majority of the dental practitioners (55%) reported using film holders. But, most of the time, 32% of the dental practitioners asked their patients to hold the films inside the mouth with their fingers for almost every exposure. A surprising finding was that 13% of the dentists held the film themselves while the radiograph was being taken of the patient.
Selection criteria and radiographic techniques
Several combinations of radiographic views were considered for the initial visit of the patient and the periapical views of a limited area were used by 87.5% of the dental practitioners. 69.5% of the dentists reported that they took the radiographs themselves, whereas 29.5% had this procedure done by an X-ray technician. The most preferred technique (80.5%) for periapical radiography was the bisecting angle technique among the dentists and 40% of them used the technique for diagnosis of dental caries.
Radiation protection for patient and personal
Almost 70.8% of the dental practitioners did not have the lead aprons. Surprisingly 84.7% of the practitioners, who had the lead aprons, did not wear the aprons [Figure 4]. 61% of the dental practitioners did not use lead apron for patient protection. Whereas, a majority (54.5%) of female dentists worn lead apron. This relationship between gender and lead apron wearers was found highly statistically significant (P = 0.000 h). 61% of the dental practitioners took radiographs for pregnant woman without any protection.
50% of the dental practitioners were not aware about the thyroid gland being the most sensitive organ to dental radiography. The relation among the age group was statistically significant (P = 0.011 S) wherein, dentists aged >36 years were aware of the fact that thyroid gland is the most sensitive organ to dental radiography. As well, none had the thyroid shield for the thyroid protection in their clinic.
The aforementioned 13% of the dental practitioners, holding the film into the patient's mouth, always stood next to the patient during the radiographic exposures. Despite 19.4% of the dental practitioners had lead barrier in their clinic, 60% followed distance rule position with 48% standing at a distance of 6 feet. There was a significant relationship between gender and distance, with the male practitioners more often standing at a 6 feet distance (P = 0.050).
Only 4% of the dental practitioners reported that they used automatic processor, 92% manual processing and 2.7% self-processing films. 58% of the dental practitioners did not check the temperature of processing solutions. 36% of the dental practitioners changed the processing solutions in 2 weeks and 24% changed in 30 days. Finally 32% dentists reported that they used view box when looking at their films, whereas 65% used a special X-ray viewing light attached to the dental chair.
Monitoring radiation exposure
Nearly 40% of the dental practitioners used systems such as film badges for monitoring radiation exposure to personnel.
| Discussion|| |
The results of this survey, which highlights the lack of knowledge regarding various aspects of dental radiography and radiation protection amongst the dental practitioners, needs to be considered in the overall context of the country.
Dentists should continuously evaluate the quality of the images produced in their ofﬁces to ensure that they are optimally exposed.  To ensure the optimum exposure conditions, quality assurance of the radiographic system should be performed. One of the basic steps of quality assurance is X-ray machine maintenance, and regular check-ups of the equipment are a necessity. , In our study, 43% of the dental practitioners performed regular check-ups of their X-ray machines. The results of the Jacobs et al.  study are consistent with the present study.
Increasing the kilo voltage much beyond 70 kVp results in a spectrum ill matched to the optimal sensitivity of dental film.  With respect to radiation protection of the patients, radiographic units with a voltage capacity between 60 kV and 70 kV are recommended.  In our survey, 27.7% dental practitioners did not know about the kVp settings of their equipment. Radiography below 45 kVp has been reported to give higher than acceptable patient skin entrance doses to produce adequate radiographic densities. 
Filtration using aluminum is an established component of dental X-ray equipment. Practically, 1.5 mm Al total filtration for X-ray equipment operating at 60-70 kVp and with 2.5 mm Al total filtration when operating above 70 kVp is advised which is followed by most of the manufacturers.  In this study, 45% dental practitioners did not know about the tube filtration of their equipment.
The size and shape of the X-ray beam have been reported as two of the most important factors in determining the dose to the patient in dental radiology.  For periapical radiography, restriction of the beam cross section to conform to the size of the image receptor (rectangular collimation) is recommended. The tissue area exposed with rectangular collimator reduces the dose of about 5 times than the area exposed with the circular cone, but unfortunately in our study rectangular collimator was used only by 7% of the dental practitioners. The results were concurrent with the Eskandarlou et al.,  Belgium (6%),  Turkey (5.5%)  and Canada (8%).  Dentists should be informed about the use of a rectangular position indicating device (PID) attached to the radiographic tube housing, which reduces the effective dose by almost 50%. 
As the X-ray beam is divergent, increasing the distance reduces the divergence within the patient and therefore reduces the volume irradiated. Two standard focal source-to-skin distances used for intraoral radiography are 20 cm (8 inch) and 40 cm (16 inch).  In our study, 44% dentists preferred 8 inch collimator whereas 11% preferred the 16 inch collimator. This is concurrent with the results of Eskandarlou et al.  According to Gibbs et al., the use of 16-inch PID results in 10-25% overall dose reduction, 38-45% dose reduction to thyroid gland and 13% dose reduction to salivary glands, than 8-inch PID. 
For intraoral radiography, E-speed or F-speed film should be used rather than D-speed film to reduce the patient exposure.  Our study showed that E-speed radiographic film is used exclusively by 75% of Dentists and D-speed film by 2%. This has been in good agreement with the data presented by Kaviani et al.  who reported about 70% use of E-Speed intraoral films in private dental clinics. In the present study, 16% of the dental practitioners were not aware of the speed of films. In the study carried out by Ilgüy et al.,  65.8% of dental practitioners were not aware of film speed. The most sensitive intra-oral film generally used in dental practice is E-speed which results in a dose reduction of 40-50%, when compared with D-speed film. Among the respondents of this study, only 2% of the dental practitioners used F Speed. Dentists should be encouraged to shift from D and E speed films to the faster F-speed film to reduce 20% radiation dose to their patients.
It has been determined that digital imaging for intraoral radiography requires about half the exposure of E-speed film and produces images largely comparable with film images and thus is an acceptable alternative.  In the present study, the rate of digital radiography use was 14%, which is consistent with the results reported by Ilgüy et al.  and Kaviani et al. 
45% of the dental practitioners reported using film holders. Film holders should be used at all times,  which prevents the repetition of exposure and thus aids in radiation protection. 
To adhere to ALARA principles it is very important to avoid ordering unnecessary radiographs.  The use of standard and accurate techniques reduces the number of retakes and indirectly reduces patients 'unnecessary exposure. Nearly 80% of the dental practitioners preferred to use the bisecting angle technique which is convenient for the patient.  This is similar to findings in Turkey,  Uganda  and Belgium.  Nonetheless, many inherent variables while performing Bisecting angle technique can result in image distortion and reproducible views are not possible.  The paralleling technique has better performance and appropriate film holders are essential for the paralleling technique. 
Standing at a distance of an average 2.2 m from the patient while taking radiographs, seems to be a safe distance.  Nevertheless, there are strong variations, with 13% of the dentists (holding the film inside the patient's mouth) staying next to the patient. Most of these dental practitioners (88%) did not wear a lead apron. In this way, there are risks of both primary radiation to the dentist finger and secondary radiation caused by the patient's body. In general, more female dentists than male dentists wore lead aprons. A potential explanation for this difference could be that female dentists might have taken this habit to wear lead aprons during pregnancy, making them more aware of radiation protection measures.  As the gonadal doses and even doses to embryo is not significant in dental radiography, the use of lead aprons has been recommended on the grounds of patient reassurance. 
The thyroid gland, one of the most radiosensitive organs in the head and neck region, is frequently exposed to scattered radiation and occasionally to the primary beam during dental radiography.  Thyroid skin exposure can be reduced by 33-84% in adults and 63-92% in children by using thyroid shield. Therefore, thyroid shielding can be applied to patients especially children as an adjunct to the use of rectangular collimation and paralleling technique. 
In our study, none of the dental practitioners had the thyroid shield for the thyroid protection in while a study done in Turkey by Ilgüy et al. showed 3.7% dentists used thyroid shield. 
Manual processing was preferred amongst 92% of the dental practitioners. Similar results were obtained by studies of Greece (97%)  and Turkey (85%). Automatic processing has a number of advantages, the most important one being the time saved.  The rate of automatic processor use (4%) was concordant with Ilgüy et al.  and Kaviani et al.  This may be because automatic processing equipment is very expensive, needs running water and electricity supply and must be cleaned frequently.  In our opinion, automatic processing and the incorporation of digital technology would help to reduce the radiation dose used, since the errors which commonly occur with manual processing would disappear.  Furthermore, the use of time-temperature processing will prevent overexposure of the patient and under processing of the radiographs, optimal radiographs will be provided. 
The dentist should view radiographs under appropriate conditions for analysis and diagnosis. Radiographs are best viewed in a semi darkened room with light transmitted through the films, and all extraneous light should be eliminated.  In our study, 65% used a special X-ray viewing light attached to the dental chair and 32% of them used a viewing light box placed beside the dental chair. Consistent results were obtained in Ilgüy et al.  study wherein 64.7% dentists reported that they used view box to interpret radiograph.
The best way to ensure that personnel are following recommended safety protection measures is with the use of personal monitoring devices.  Several types of dosimeters including the thermo luminescence dosimeter, photoluminescence glass dosimeter, or optical stimulated luminescence dosimeter could be used to measure the exposure.  The results of the present study (40%) on the use of personal monitoring devices concur with the results of studies carried out by Kaviani et al. 
| Conclusion|| |
The results indicate that for minimizing any unnecessary radiation, attempts should be made to improve dentists' knowledge about radiation dose reduction techniques. One of the limitations of an investigation of this nature is the possibility of bias. It is possible that some answers may represent the ideal situations intended by the respondents, but adherence to these standards may be lax in other times or areas of practice. Thus, variation in standards may occur within dental clinics that are not reflected in our results. Continuing educational programs can help to improve the radiation safety for dental patients as well for the operators.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]