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Year : 2008  |  Volume : 20  |  Issue : 2  |  Page : 45-48 Table of Contents   

Radiation protection protocol observed amongst dentist population in the union territory of Puducherry

Department of Oral Medicine and Radiology, Mahatma Gandhi Postgraduate Institute of Dental Sciences, Puducherry, India

Correspondence Address:
G Sitra
Postgraduate Student, Dept. of Oral Medicine and Radiology, Mahatma Gandhi Postgraduate Institute of Dental Sciences, Indira Nagar, Puducherry- 605006
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0972-1363.44363

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The risk involved with dental radiography is certainly small in comparison with many other risks that are a common part of everyday life. However, there is no basis to assume that it is zero. Though the radiation dose levels in dental practice are relatively low, one should consider the cumulative effect of repeated exposures. There should be a striving for implementation of radiation protection measures and selection criteria for radiography in private dental offices. This article presents the results of the survey conducted in the private dental offices in the Union territory of Puducherry to gain insight into the knowledge and attitude of the Puducherry dentists towards radiation protection.

Keywords: Private dental offices, Puducherry, radiation protection, radiography and survey

How to cite this article:
Sitra G, Daniel M J, Srinivasan S V, Prashad KV. Radiation protection protocol observed amongst dentist population in the union territory of Puducherry. J Indian Acad Oral Med Radiol 2008;20:45-8

How to cite this URL:
Sitra G, Daniel M J, Srinivasan S V, Prashad KV. Radiation protection protocol observed amongst dentist population in the union territory of Puducherry. J Indian Acad Oral Med Radiol [serial online] 2008 [cited 2023 Feb 5];20:45-8. Available from: http://www.jiaomr.in/text.asp?2008/20/2/45/44363

   Introduction Top

We live in a sea of radiations. We are constantly exposed to naturally occurring ionizing radiation i.e., background radiation and also exposed to ionizing radiation from man-made sources, mostly through medical procedures. On an average, doses from a diagnostic X-ray are much lower, in dose effective terms, [1] than the natural background radiation.

The primary risk from dental radiography is radiation induced cancer. [1] The literature on possible harmful effects of professional diagnostic exposure for dentists is not consistent. The risk involved with dental radiography is certainly small in comparison with many other risks that are a common part of everyday life, however, no basis exists to assume that it is zero. [1] Also, the biologic effects of ionizing radiation absorbed during dental radiography are uncertain. [2],[3]

Dental examinations rank among the most frequent radiographic procedures. The individual levels of exposure are low relative to other diagnostic procedures, but the high frequency and the youthfulness of the age groups predominantly exposed to them justify seeking a finer tuning of radiation protection. [4]

The regulatory bodies

International Commission for Radiation Protection (ICRP) is the regulatory body which lays down norms for radiation protection at the international level. In India, it is the Atomic Energy Regulatory Board (AERB), [5] which provides the norms for radiation protection.

Role of AERB

AERB recommends norms for permissible doses of radiation from X-ray tubes, the shielding required for the walls of an X-ray tube room, the lead equivalent shielding apparel to be worn by radiation workers and lays down safe dose limits for radiation workers and for the general public. [5]

Potential risks and benefits of exposure

Before undertaking any radiological examination, it is important that the provider understands the potential risks and the benefits of radiation. The risks can be stochastic (of which probability increases with dose) [1] and deterministic (of which severity increases with dose). [1] Cancer induction and genetic effects are stochastic effects and cataracts, blood dyscrasias and impaired fertility are examples of deterministic effects.

Principles of radiation protection

The current radiation protection standards are based on 3 general principles: Justification of a practice, optimization and dose limitation. [5],[6]

Although the radiation dose levels in dental practice are relatively low, one should consider the cumulative effect of repeated exposures. There should be a striving for radiation protection measures in the private dental offices.

With this background, we performed a survey in the private dental offices to gain insight in the knowledge and attitude of the Puducherry dentists towards radiation protection.

   Materials and Methods Top

A printed questionnaire was distributed in person among 60 private dental offices in Puducherry. They were selected and surveyed based on the use of intraoral radiographic equipment. The dentists were informed about the anonymous processing of the questionnaire.

The questions related to radiation protection were composed in such a way that they would allow assessment of the compliance of the dental offices to the AERB recommendations; Information was obtained on the type of image receptor-analogue or digital, exposure settings, number of exposures, distance from the radiation source and the presence and composition of shielding wall.

   Results Top

The response rate among the dentists was 100%, of which 36 were male and 24 were female. Eighty percent of dentists had less than 10 years of experience; 82.5% were general dental practitioners and 17.5% were specialists. 52.5% were below 29 years of age [Figure 1].

Characteristics of the radiographic equipment

In 80% of the equipments, radiation tubes of 65-70 kVp were used. The tube current of most users (87.5%) were 10 mA. About 57.5% of the dentists used electronic timer.

72.5% of dentists claimed to adjust exposure time according to the tooth location, patient characteristics, kVp and film speed. The exposure time varied between 0.01 s and 1.5 s, with an average of 0.64 s [Figure 2].

Radiographic film and collimation

Digital radiographic receptors were used by only 10% of dentists with median exposure time of 0.4 s. Analogue radiographs were mostly of the higher speed class i.e., E speed (67.5%). About 17.5% dentists used both D/E speed and only 5% of dentists still using the D-speed film [Figure 3].

Most of the dentists using faster analogue film speed classes made an effort to reduce the exposure time and statistically significant difference was observed (Kruskall - Wallis test, P <0.05). Less effort was made by the dentists to reduce the exposure time when they used higher kVp equipment. This observation was found to be statistically insignificant (Kruskall - Wallis test, P >0.05).

50% of dentists claimed to use aiming devices; whereas 12.5% of dentists assisted in holding the film inside the patient's mouth for almost every exposure.

Rectangular radiation collimators were used by 7.5% dentists, cylindrical collimators by 77.5% and pointed collimators by 15% dentists.

Radiographs made per month

On an average, 60% of dentists took less than 40 radiographs per month, 27.5% took 40-80 radiographs and 12.5% of dentists took more than 80 radiographs per month.

There was no statistical significance between the exposure time/kVp and radiographs made per month (Chi Square test; χ2 = 3.77 and 2, respectively; P >0.05).


The average distance of the dentists from the radiation tubehead was 5.48 ft. About 12.5% of dentists held the film inside the patient's mouth and none of them wore lead aprons.


About 42.5% of dentists stood behind a protective wall during radiation exposure. Spearman rank correlation showed no statistically significant difference between age and the use of a protective wall ( R = -0.0506, P >0.05) or between gender and the use of a protective wall (Spearman rank correlation, R = -0.0053, P >0.05).

The wall was made of hard bricks (15%), concrete (15%), plaster work (12.5%) and other materials e.g., glass (42.5%).

Relative position from patient and radiation tube

Most of the dentists (67.5%) varied their position according to the position of the radiation tube during exposure.

The relationship between age and their relative position and that between gender and their relative position were found to be statistically insignificant (Spearman Rank correlation: R =0.0613, P >0.05 and R = -0.0504, P >0.05, respectively).

   Discussion Top

When analyzing the exposure parameters of the intraoral radiographic equipment, it was found that most dentists used kVp settings between 65 and 70 kVp which is in accordance with the guidelines.

The increased use of E-speed film is encouraging. Some difference in exposure time settings between different film speed classes was observed. The fact that the radiation dose could be reduced by 50% when changing from D to E-speed film [8] is thus put into practice in many of the dental offices.

The increased use of electronic timer is reassuring, as higher precision could be reached, especially in short exposure time ranges.

The difference in exposure time between analogue (0.64 s) and digital receptors (0.4 s) is 62.5% in the present study. The Belgian survey [7] and Norwegian [8] survey showed 55% reduction in exposure time.

The fact that film holders are being used by 50% of dentists deserves some attention. This number is comparable with the results of surveys conducted among Belgian dentists [7] and Syrian dentists [9] where about 60 and 43% of responders, respectively used film holders.

Even more important was the relatively large percentage (12.5%) of dentists who held the film inside the patient's mouth while exposing. This points to a general underestimation of the potential risks of radiation exposure. Among them, only 6% of dentists wore lead apron. Thus, there are risks of both primary and secondary radiation to the dentist's finger.

Although the rectangular collimator of radiation beam which limits the exposure area by a factor of three to four [3],[10] is recommended, it is used only by 7.5% of dentists. The pointed collimators, which produces more scattered radiation is used by 15% of dentists. The Belgian survey [7] showed only 6% use of rectangular collimators and the Damascus survey [9] showed even a total absence of its use.

The dentists stood at an average distance of 3m from the patient while taking radiographs, which seems to be a safe distance. [1],[11]

It should be mentioned that in 55% of cases, dentists are standing behind a wall made of plaster, glass and wood. Of course, this behavior may create a false feeling of protection.

The position of the practitioner to the radiation tube and the patient in most cases is determined by physical constraints of the design of the dental office. In our study, about 67.5% of dentists changed their position according to the direction of radiation tube, which shows their knowledge regarding radiation protection.

   Conclusion Top

The current survey emphasizes on the need for further implementation of radiation protection principles among general dental practitioners in the private dental offices in Puducherry. Though many of the dentists adapted the exposure time to faster film speed classes, the decreased use of rectangular collimators, shielding wall and other protective measures are disappointing.

Imaging examinations are performed to get maximum information at lowest possible dose to both the patient and the provider. So, practitioners should be aware of the possible hazards involved with use of X-rays and should strive hard to implement the various protective measures into practice.

   References Top

1.Frederiksen NL. Health physics. In: White SC, Pharoah MJ. Oral radiology, Principles and interpretation. 5th ed. Missouri: Mosby-year book; 2004.  Back to cited text no. 1    
2.Freeman JP, Brand JW. Radiation doses of commonly used dental radiographic surveys. Oral Surg Oral Med Oral Pathol 1998;77:285-9.  Back to cited text no. 2    
3.White SC. Assessment of radiation risk from dental radiography. Dentomaxillofac Radiol 1992;21:118-26.  Back to cited text no. 3  [PUBMED]  
4.Aroua A, Buchillier-Decka I, Dula K, Nedjadi Y, Perrier M, Vader JP, et al. Radiation exposure in dental radiology: A 1998 Nationwide survey in Switzerland. Dentomaxillofac Radiol 2004;33:211-9.  Back to cited text no. 4  [PUBMED]  [FULLTEXT]
5.Grover SB, Kumar J, Gupta A, Khanna L. Protection against radiation hazards: Regulatory bodies, safety norms, dose limits and protection devices. Indian J Radiol Imaging 2002;12:157-67.  Back to cited text no. 5    Medknow Journal
6.2006 recommendations of the International Commission on Radiological Protection. Draft for consultation. Available from: http://www.icrp.org/docs/2006-recs-CONSULTATION-Draft.pdf.  Back to cited text no. 6    
7.Jacobs R, Vanderstappen M, Bogaerts R, Gijbels F. Attitude of the Belgian dentist population towards radiation protection. Dentomaxillofac Radiol 2004;33:334-9.  Back to cited text no. 7  [PUBMED]  [FULLTEXT]
8.Wenzel A, Moystad A. Experience of Norwegian general dental practitioners with solid state and storage phosphor detectors. Dentomaxillofac Radiol 2001;30:203-8.  Back to cited text no. 8    
9.Salti L, Whaites EJ. Survey of dental radiographic services in private dental clinics in Damascus, Syria. Dentomaxillofac Radiol 2002;31:100-5.  Back to cited text no. 9  [PUBMED]  [FULLTEXT]
10.Underhill TE, Chilvarquer I, Kimura K, Langlais RP, McDavid WD, Preece JW, et al. Radiologic risk estimation from dental radiology, Part I: Absorbed doses to critical organs. Oral Surg Oral Med Oral Pathol 1998;66:111-20.  Back to cited text no. 10    
11.Langland OE, Langlais RP. Radiologic health and protection. In: Langland OE, Langlais RP, editor. Principles of dental imaging. Philadelphia: Lippincott Williams and Wilkins; 1994.  Back to cited text no. 11    


  [Figure 1], [Figure 2], [Figure 3]


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