In dentistry

In dentistry, radiographs are very helpful in detecting oral diseases, cavities, bone related problems, treatment planning. And it should be clinically justified to obtain maximum benefit and reduce further effects. (Awooda, 2016)

Dental radiation is considered of small dose, however cumulative exposures may lead to irreversible damage, it is also an integral part of clinical dentistry. As a result, radiographs are often referred as the clinician’s main diagnostic aid. Despite it carries a potential harm and the exposure to dental radiation should be minimized where practicable (Behal, 2016).

An official document done by IADMFR (International Association of Dentomaxillofacial Radiology) Association (2007) stated that: it is widely accepted that dental practitioners and dental radiography operators should not carry out a diagnostic x-ray exposure without having adequate training. Dental practitioners and dental radiography operators should complete training, including theoretical knowledge and practical experience in:
• Radiation production, radiation protection and statutory obligations relating to ionizing radiation as a relevant to their functions as a practitioners or operator and;
• Diagnostic radiology as significant to the specific area of practice.

2.3 CLASS LICENSE UNDER ACT 304 FOR DENTAL PRACTITIONERS
According to obtain class license under the Atomic Energy Licensing Act (ACT 304) from the Ministry of Health Malaysia, stated that person who operates the apparatus should be:
? A qualified radiographer, full time or part time.
? An x-ray operator currently employed in the clinics ; has trained in the orientation programme conducted by college of general practitioner’s society of Malaysia. He/she be restricted to procedures he/she has been trained to be; or
? A medical or dental practitioner.

2.4 KNOWLEDGE OF DENTAL RADIOLOGY

According to survey done by de-Azevedo-Vaz, et.al, (2013) on dental undergraduate’s knowledge of dental radiology, the obtained results demonstrated that Third and Fourth-year students showed less knowledge of the interpretation domain. These students are closest to entering the professional field and this lower knowledge should concern the clinical practice because a thorough knowledge of various available radiographic modalities, their application and accurate interpretation of the images and obtained data is necessary for the ethical and efficient practice of dentistry.
An evaluation study done by S ; A (2014) it shows that 5th year students have high percentage 73.9% of correct answers and possible explanation for this might be that they have been practicing three years on clinical field, so they obtained the fair amount of knowledge and experience of identifying the anatomical landmark such as maxillary sinus. In contrast, the 4th year students demonstrated that they have low percentage 63.6% than 5th year of correct answers although they have more experience in dental practicing than 3rd year.
The errors in periapical radiographs can be categorized into the followings: x-ray equipment, the image receptor, processing the patient, the operator and the radiographic technique. The most frequent errors were processing errors (23.5%), cone cut (20.2%) ; incorrect vertical angulation (15.1%). The processing errors revealed 9.6% in 4th year ; 43.7% in 5th year. A possible explanation for this might be a lack of adequate knowledge about the basic of processing. In addition, the 5th year students have a lot of clinical requirements to be finished. Therefore, they might attempt to finish the processing in hurry. On the other hand, crown not shown was found 0.8% in 5th year while 14.4% in 4th year. Therefore, it seems possible that these results are due to the 4th year students have less experience in radiographic practice (Almogbel, 2014)

Aydin Ü, (20014) revealed incorrect angulation done by under graduate students was most frequent in the maxillary molar region followed by maxillary premolar, maxillary anterior regions. Also, a study done by Almogbel, (2014) stated that same thing the incorrect vertical angulations were mostly detected in maxillary anterior (35.7%) followed mandibular premolar (27.8%) the possible explanation for high percentage at maxillary anterior is the anatomical angulation of jaw.

A study done by Scott McNab, (2015) stated that contrary to predictions, graduate dentists scored significantly higher than undergraduate dentists in the identification of pathology on panoramic radiographs (PRs), as mean score shows 4.7/10 vs 3.5/10. The result may indicate an area of the undergraduate curriculum that requires additional attention. Even though there are no comparative studies that have directly examined the ability of students or graduate dentists to diagnose pathology on panoramic radiographs.
According a study done by S. Elangovan, (2016) that there is reduction of improper vertical angulation (39%), film position error (33.4%) and improper horizontal angulation (27.6%) in taking and processing errors. As compared among 4th year and 5th year students, it shows that 5th year students (37.3%) outperformed than 4th year (13.2%). This clearly indicates that experience reduces the error occurrence frequency among students. Whereby a study done by Patel JR, (1986) seems opposite about the study, as he stated that the incorrect film placement followed by incorrect vertical angulation and cone cutting were most common errors in paralleling technique.

2.5 RADIATION PROTECTION AWARENESS

Radiation protection is to provide an appropriate level of protection for humans without unduly limiting the beneficial actions giving rise to radiation exposure. It is also to prevent the occurrence of harmful deterministic effects and to reduce the probability of occurrence of stochastic effect. (HORNER, 1994)

As stated by Swapna, et al., (2017) that there are guiding principles in radiation protection. Firstly, the principle of justification, in making dental radiographs this principle obligates the dentist to do more good than harm. Secondly guiding rule is the principle of optimization, this principle holds that dentists should use every means to reduce unnecessary exposure to their patient and themselves. Thirdly the principle is dose limitation, dose limits are used for occupational and public exposures to ensure that no individual are exposed to unacceptably high dose.

According to a study done by Enabulele ; Igbinedion (2013) stated poor knowledge of meaning of ALARA principle was observed as only 17.9% of the students knew what the acronyms meant. It can be deduced that these students who were unfamiliar with the term may not be able to apply the principle of ALARA in practice. Consequently, patients may receive unnecessary radiation dose if ALARA principle is not put into practice. Furthermore, none of the students knew the annual radiation dose limit for dentist.

According to a study done by Reddy, Krishnan, Ramesh, Krishna, ; Praveen, (2017) the percentage of dental students that always wore lead apron was 20% which is good increase compared to study carried out by Jacobs, Vanderstappen, ; Gijbels, (2004) where by only 12% of dental students wore lead apron while operating an x-ray unit. The reason for not wearing a lead apron among dental undergraduate students might be attributed to the non-availability of lead apron and increased weight of the apron (Behal, 2016)

The American Dental Association (ADA) , American Board of Oral ; Maxillofacial Radiology (ABOMR) ; North Carolina Regulations for Protection against Radiation (NCAC) recommend dentists perform radiographic examinations using optimal radiographic techniques to achieve radiation safety ; diagnostic image quality. ADA guidelines consider the dentist’s responsibility to follow the ” as low as reasonably achievable principle for radiographic practice (ALARA) prior to making the decision to obtain radiographic.

Jayasilan, (2015) conducted a survey in 2015 to access th knowledge of undergraduate dental students on radiation protection: 44% of students are not aware of ALARA. It shows that students are not well aware of radiation and it’s harmful effects and have not been implementing the safety precautions in practice. Poor knowledge of meaning of ALARA was observed, it can be deduced that these students who were unfamiliar with term may not be able to apply the principle of ALARA in practice.

A study done by Byung-Do Lee, (2013) showed that only 21.7% of dentists draped lead apron or thyroid collar cover patients, to point that a relatively high percentage of dentists were unaware of potential of thyroid exposure. Considering every reasonable precaution should be taken to minimize radiation exposure, protective thyroid collars and aprons should be used whenever needed.

As stated by R Jacobs, (2004) that the practitioner stands on average at 2.2m distance from the patient while taking radiographs, which seems to be a safe distance. However, there are strong variation with 8% of dentists holding the film inside the patient’s mouth, staying next to the patient. Most of these dentists (88%) do not wear lead apron, so there are risks of both primary radiation to dentist’s finger and secondary radiation caused by patient’s body.