|Year : 2016 | Volume
| Issue : 1 | Page : 17-22
Radiation Protection Awareness and Practices in Cameroon Dental Health Care Facilities
Ashu Michael Agbor1, Clement Chinedu Azodo2
1 Department of Community Dentistry, Universite des Montagnes Dental School, Bagante, Cameroon
2 Department of Periodontics, University of Benin, Benin City, Edo, Nigeria
|Date of Web Publication||27-Jun-2016|
Clement Chinedu Azodo
Department of Periodontics, Prof. Ejide Dental Complex, University of Benin Teaching Hospital, P.M.B. 1111, Ugbowo, Benin City 300001, Edo
Source of Support: None, Conflict of Interest: None
Introduction: Strict adherence to the radiation exposure guidelines is mandatory when using X-rays for disease detection in order to minimize its harmful effects. The objective of this study was to determine the radiation protection awareness and practices in Cameroon Dental Health care facilities. Materials and Methods: This multiregional questionnaire-based study was conducted among dental clinics located in the capitals of the Littoral, Central, South West, and North West regions of Cameroon. Results: The majority 63 (90.0%) of the participants reported awareness of the adverse effects of radiation on patients and dental professionals. Only 22.9% reported awareness of the agency in-charge of X-ray protection and standardization in Cameroon. The majority of the X-ray machine were located inside the operating room of the dental clinic. The most vulnerable group to the effects of radiation reported was pregnant women while the most vulnerable part of the body to the effects of radiation reported was reproductive organs. The lead shield was the dominantly utilized radioprotective device among the participants. Six meters away from the direction of radiation was the most frequently adopted radioprotection positioning among the participants. Conclusion: Data from this study revealed that many aspects of radiation protection in dental radiology is suboptimal; hence, specific training in education and training in radiation protection is deemed necessary among dental health care professionals in Cameroon. It is recommended that Cameroon National Radiation Protection Agency should establish radiation protection guidelines in dental health care delivery.
Keywords: Awareness, dental radiology, knowledge, practices, radiation protection
|How to cite this article:|
Agbor AM, Azodo CC. Radiation Protection Awareness and Practices in Cameroon Dental Health Care Facilities. Indian J Oral Health Res 2016;2:17-22
|How to cite this URL:|
Agbor AM, Azodo CC. Radiation Protection Awareness and Practices in Cameroon Dental Health Care Facilities. Indian J Oral Health Res [serial online] 2016 [cited 2019 Jun 15];2:17-22. Available from: http://www.ijohr.org/text.asp?2016/2/1/17/184729
| Introduction|| |
Radiation from diagnostic X-rays constitutes the second largest source of whole body radiation exposure.  The diagnostic X-rays are classified into dental and medical X-rays based on the health care sector in which it is routinely performed. Dental X-rays are one of the most frequent diagnostic investigations accounting for nearly one-third of the total number of radiological examinations in developed countries.  Radiological examination is an integral part of clinical dental practice, offering incalculable benefits to the clinicians and patients. Its roles range from diagnosis, treatment planning, treatment guidance, prediction of prognosis to monitoring of treatment outcome.  The estimated average number of radiographs per examination across intraoral and panoramic procedures in the literature is 1.75-1.78. ,
The exposure to radiation from these diagnostic X-rays exerts adverse effects on humans, and these effects are classified as deterministic and stochastic effects. The various histopathological reactions of tissues and organs that follow localized tissue irradiation, and the radiation syndromes that follow total body irradiation, constitute the deterministic effects while genetic effects and carcinogenesis constitute the stochastic effects.  Although no threshold is assumed for stochastic effects, the probability of stochastic effects characteristically dose-dependent but the severity of the effects is independent of the dose.  The substantial reduction in radiation dose without compromising medical effectiveness is therefore necessary to reduce the stochastic radiation effects.  The optimization of radiation protection in order to minimize the effective dose exposure to patients and health care providers cannot be overemphasized.  The reason to optimize the radiation protection in dentistry is because the repeated exposures to the relatively low radiation doses of routine dental X-ray heightens the risk of adverse consequences from cumulative doses. A dental X-ray gives about 1 mrem, and a chest X-ray about 6 mrem, but nearly all other X-rays give far higher exposures: Pelvis, 90 mrem; abdomen, 150 mrem; spine, 400 mrem; and barium enema, 800 mrem.  The higher dental radiological exposure among the younger age groups may also allow enough time for the manifestation of the deterministic effects of radiation. A number of epidemiological studies have provided evidence of increased risk of brain, salivary gland, and thyroid tumors from dental radiography.  The potential risk of radiograph inducing a fatal cancer in an individual has been estimated to be approximately 1 in 4 million per millirem.  The estimate of the probability of fatal cancer by the International Commission on Radiological Protection is 4 × 10−2 per microsieverts (Sv) for a working population and 5 × 10−2 per Sv for the total population. 
Dental radiation protection should be considered as a rule, which must be respected in order to protect health care providers, patients, and the environment. This should be in strict adherence to the as low as reasonably achievable (ALARA) concept which states that all exposure to radiation must be kept to a minimum.  All exposures to X-rays should be clinically justified and each exposure should be expected to give the patient a net positive benefit.  Proper radiation protection measures in dental radiology include shielding, the adoption of recommended distance, and position to avoid occupational exposure to X-radiation (primary radiation, leakage radiation, and scatter radiation). During X-ray exposure, thyroid collar, lead apron, fast film, and film holding devices are used to protect the patients from excess exposure to radiation. Proper selection of exposure factors and good technique are also used for patient protection. Quality assurance program plays an essential part in dental radiation protection by improving diagnostic yield and limiting repeat examinations.  Dental X-ray machine must be monitored for leakage radiation through the use of a film device that can be obtained from the dental X-ray equipment manufacturers. In developing countries, old and obsolete radiation equipment are usually used without monitoring, posing a high potential occupational radiation exposure from leakage radiation, which occurs from faulty dental X-ray tube head seal. 
Legislations for X-radiation protection of the environment and workers in industries and health care in developing countries are either nonexistent or unimplemented because of lack of concern, inadequate manpower, and logistics. In Cameroon, the agency responsible for radiation protection is the National Radiation Protection Agency (NRPA), which was in the news on their acquisition of new state of the art equipment for determining the levels of exposure to ionizing radiation to which hospital and industrial workers in the country are subject to.  The importance of radiographs in dentistry justifies the need for proper radiation protection. The objective of this study was to determine the radiation protection awareness and practices in Cameroon Dental Health care facilities.
| Materials and methods|| |
The protocol for this study was reviewed and approval granted by the Cameroonian Ministry of Higher Education and Scientific Research.
This cross-sectional study was conducted among dental clinics located in Douala, Yaounde, Buea and Bamenda, which are the regional capitals of the Littoral, Central, South West, and North West regions of Cameroon, respectively.
A total of 71 dental clinics were approached but seventy of them consented and participated giving a 98.6% participation rate. The authority of consenting clinics nominated a participant who is actively involved in exposing patients to X-rays. Informed consent was obtained from the nominated participant before the data collection.
Data collection tool
A pretested self-administered questionnaire designed by the authors was used for data collection and distributed to dental clinics with one nominated member of the dental team participating per clinic. The questionnaire was anonymous without identifiers. The questionnaire elicited information on professional status (dentist or dental auxiliary who are dental paraprofessionals), the frequency of radiograph daily, personnel involved in radiography, and area for taking radiographs. Other information obtained were the maintenance of X-ray machine, knowledge of the effects of radiation on patients and health care providers, measures taken to prevent radiation exposure to both patient and dental health care provider, and awareness of the existence of the National Radiation Agency in Cameroon.
Data collection procedure
The questionnaires were hand delivered to the appointed representatives of the studied dental clinics and collected after filling the same day.
Data were subjected to descriptive and nonparametric statistics in the form of frequencies, percentages, and cross tabulation using Epi-Info, version 3.5.2 (Center of Disease Control and Prevention, Atlanta, USA). Chi-square was used to assess the strength of association and P < 0.05 was considered significant.
| Results|| |
The response rate for the study (70/71) was 98.6%.
Demographic characteristics of the participants
The majority of the participants were males (57.1%) and dental auxiliaries (51.4%). The age range of the participants was 23-58 years, and their mean age was 38.5 ± 8.5 years. The government and private owned dental clinics recorded 40.0% each. Most of the participants (94.3%) indicated that they have received training in dental radiography. Only three (4.3%) participants claimed that they have digital X-ray units in their clinic. Twenty-one participants (30.0%) claimed that they shoot, on average, more than three radiographs on a daily basis. Only four (5.7%) of the participants reported that their clinic X-ray machine was checked regularly [Table 1].
|Table 1: Demographic characteristics and radiation awareness of the participants |
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Awareness of adverse effect of the radiation and Cameroon radiation regulatory agency
Although a majority 63 (90.0%) of the participants reported awareness of the adverse effect of the radiation on patients and dental professionals, only 22.9% reported awareness of any agency in-charge of X-ray protection/standardization in Cameroon [Table 1].
Vulnerable groups to effect of radiation
Pregnant women, children, and the aged were reported as the most vulnerable group to effects of the radiation in descending order. There is no statically significance association between type of hospital, knowledge of vulnerable groups to effect of radiation, awareness of the adverse effect of the radiation, and Cameroon radiation regulatory agency (P > 0.05) [Table 1].
Vulnerable organs to effect of radiation
Reproductive organs were reported as the most vulnerable part of the body to effects of the radiation followed by the thyroid gland. However, about one-third 23 (32.9%) stated no knowledge. There was a statistically significant association between the location of the dental clinic and the most vulnerable part of the body to effects of the radiation (P = 0.01) [Table 2].
Location of X-ray machine, radioprotection device, and positioning
In terms of geographical location of the X-ray machine, majority of the machine were inside the clinic [Table 3]. The lead shield was the dominantly utilized radioprotection device among the participants. Six meters away from the direction of radiation was the most frequently adopted radioprotective positioning among the participants. One-fifth of the participants utilized perpendicular position to the ray of radiation. There is no statically significance association between type of hospital, clinic X-ray machine position, radioprotection positioning, and device among the participants (P > 0.05) [Table 3].
|Table 3: Clinic X-ray machine position, radioprotection positioning, and device among the participants |
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| Discussion|| |
The implications of the young age of the participants are on the radiosensitive nature of tissues of younger people and that their prospective lifespan is likely to exceed the latent period of ionizing radiation. Added to this is the cumulative radiation exposure as 48.6% and 30.0% among the participants exposes 1-3 radiographs and more than three radiographs on the average daily, respectively.
Radiation protection agency in any country whether developed or developing country is expected to ensure that radiation safety legislation, established to protect the patient, operator, and the general public from radiation hazards are strictly adhered to. In this study, 63 (90.0%) of the participants reported awareness of the adverse effect of the radiation on patients and dental professionals but only 22.9% were aware of the agency in charge of radiation in Cameroon, NRPA. This indicates that radiation control in dental practice may be poorly controlled due to the nonactive and functionality of agency in charge of monitoring and evaluation. This can be explained by reports of previous studies which stated that dentists who considered the laid down regulations by their country's National Institute of Radiation Protection as wholly adequate had a high care attitude and dentists with high concern about radiation hazards, restricted their use of X-ray examinations.  The anecdotal information on many X-ray equipment used in Cameroon are fairly used, noncompliant with international standard, and have few engineers to effect repair thereby necessitating the need for Cameroon radioprotection agency to take a proactive step. Report of a study in Uganda revealed that most of the X-ray equipment in that country were more than 30-year-old and only 15% of dentists knew when the equipment was last serviced.  There is therefore a need to increase radiation knowledge among oral health workers in Cameroon and improve collaboration between National Agency for Radiation Control and the Oral Health care workforce.
Long-term effects are associated with small amounts of radiation absorbed repeatedly over a long period. Repeated low levels of radiation exposure are linked to the induction of cancer, birth abnormalities, and genetic defects. Individual risks in dental radiography are small but are greater in the younger individuals below 30 years who are most frequently exposed. The regulation 6(1)(e) of IR(ME)R 2000 prohibits the carrying out of a medical exposure on a female of child-bearing age without an enquiry as to whether they are pregnant.  Such an enquiry will not normally be necessary in dental radiography except in vertex occlusal projection because the primary X-ray beam is likely to irradiate the pelvic area. If the examination is undertaken, the fetal dose must be kept to a minimum consistent with the diagnostic purpose, and the use of a lead apron is advised, principally because of the reassurance, it provides. In this study, pregnant women were considered as the most vulnerable group to the effects of radiation followed by children and the aged. The well-documented embryological effect of radiation with obvious congenital defect in the literature may be the reason for this information among the participants. It is recognized that dental radiography is often avoided if the patient is known to be pregnant, essentially for psychological reasons. For the vast majority of dental projections, the pelvic area is not irradiated, and an acceptable course of action would be to explain to the pregnant patient that a dental radiograph delivers such a small dose to the fetus that the associated risk can be regarded as negligible. However, because of the emotive nature of radiography during pregnancy, the patient could be given the option of delaying the radiography. Children are susceptible to radiation damage than adults with the developing fetus being more vulnerable. The aged as rightly indicated by the participants are the least vulnerable based on the fact that latency period of radiation effect may outlive their life span.
Disease detection is one of the most important uses of dental radiographs. X-radiation is harmful to living tissues but because the benefit of disease detection outweighs the risk of biologic damage, it has remained a part of daily dental practice. However, more radiation damage is known to occur with high doses because a rapid delivery of radiation does not allow time for cellular damage to be repaired. Extensive radiation injury also occurs when large areas of the blood are exposed because of the damage to the blood-forming tissues. Critical organs exposed during dental radiographic procedures in the head and neck region include the following: Skin, thyroid gland, lens of the eye, and bone marrow. The most vulnerable part of the body to effects of the radiation was identified as thyroid by 10% with better knowledge obtained from the South West region while the majority of the participants reported reproductive organs. Although the sensitivity of reproductive organs to effect of radiation is linked to their replication rate, their exposure in dental radiographs is minimal. The thyroid gland has been identified as a critical organ in dental radiology because its damage diminishes the quality of life of the affected person.  The noted geographical difference in knowledge of most vulnerable part of the body to effects of the radiation is in consonance with geographical differences in health practices among health workers. Despite the noted knowledge about the most vulnerable part of the body among the participants, one-third (32.9%) lacked knowledge of vulnerable part of the body. This general lack of knowledge is cause for concern, not only because of the standard of radiation protection that is being practiced for the patients' benefits, but also for their own protection. About one-third (32.9%) of the participants gave do not know responses which collaborated the high level of "don't know" responses reported in a survey among Ugandan dentists. 
Although radiographs are indispensable diagnostic tools, the increased effective doses of common intraoral and extraoral imaging techniques are high enough to warrant reconsideration of means to reduce patients' exposure.  Adequate shielding can greatly reduce the occupational exposure in dental radiology. Protective barriers that absorb the primary beam can be incorporated into the office design, thus protecting the operator from primary and scatter radiation. Whenever possible, the dental radiographer should stand behind a protective barrier such as a wall during X-ray exposure. Most dental offices incorporate adequate shielding in walls through the use of several thickness of common construction materials such as a dry wall.
However, in this study, most of the X-ray machines were located inside the dental clinic making shielding a priority in radiation hazard protection. Lead protection of the abdomen has little relevance to dental radiation protection; however, thyroid shielding has some value.  Exposure reduction by the shielding varied from 5% to 56% for a complete-mouth survey, 2-18% for a bitewing survey, and 10-79% for a panoramic survey. In a study, thyroid skin measured were 63-92% lower on children and 33-84% lower exposures on adults in offices in which shields were used as compared to offices in which they were not used.  The use of thyroid protection collars is an effective preventive measure against exceeding occupational organ dose limits which considerably reduces the effective dose. Therefore, thyroid protection collars should be a required component of dental X-ray protection in accordance with the ALARA principle. , However, lead apron and thyroid shield was the most and rarely used radioprotection device, respectively, in this study. In comparison, leaded aprons in 95% for extraoral films and thyroid collars in 85% for intraoral films were among the radiation dose-reducing strategies adopted in the North American Dental Schools.  Personal lead shielding devices significantly reduce gonadal dose in the case of accidental exposure.  Dose estimation revealed significantly larger effective dose per year in some dentists is explainable by lower lead aprons use.  The general poor knowledge and practices regarding radiation protection may lead some dentists and patients to receive considerably higher radiation doses than those recommended by the International Commission on Radiology protection unknowingly.
One of the most effective ways for the operator to avoid the primary beam and limit X-radiation exposure is distance. The dental radiographer must stand at least 6 feet away from the X-ray tube head during X-ray exposure. When maintaining this distance is not possible, the protective barrier must then be used. Another important way for the operator to avoid the primary beam is to maintain proper positioning during X-ray exposure. To avoid the primary beam, which travels in a straight line, the dental radiographer must be positioned perpendicular to the primary beam, or at 90° to 135° angle to the beam. About one-third of the participants (31.4%) stand at least 2 m square in the direction of radiation, 20.0% perpendicular to the direction the ray of radiation, 37.1% at least 6 m away from the direction of radiation, and 10.0% in the direction of the radiation. A study in Belgium  showed that the distance of the dentist to the radiation tube during exposure was on the average 2.2 m, although 8% of the dentists assisted in holding the image receptor inside the patient's mouth.
| Conclusion|| |
Data from this study revealed that many aspects of radiation protection in dental radiology is suboptimal; hence, specific training in education and training in radiation protection is deemed necessary among dental health care professionals in Cameroon. It is recommended that Cameroon NRPA should establish radiation protection guidelines in dental health care delivery.
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[Table 1], [Table 2], [Table 3]