Dental Radiography: Techniques, Procedures, And Safety Measures

1. List at least ten measures that can be taken to miinimise radiation for patients, operators and others?

2. List and describe at least five patient requirements that should be considered when taking a dental radiograph.

3. Explain, using your own words how you would position an x-ray film to take a periapical x-ray of maxillary molars. Include in your answer a suggested film size, and what your x-ray will show. Once the x-ray has been taken, what steps do you take to label and mount the film?

4. What are the requirements for the operator when using the bisected angle technique? Include in your answer your understanding of using a periapical film holder.

5. What is the Radiation Act and Code of Practice for radiation protection in dentistry? Explain, in your own words, the main objective of the Act, who the Code applies to and the requirements for radiation protective measures.

Measures to Minimize Radiation Exposure

Q1) List at least ten measures that can be taken to minimise radiation for patients, operators and others?

Measures to be considered to minimise the radiation for patients, operators and others are as follows (Arpansa.gov.au, 2019):

• Unnecessary people should not be allowed in the radiation room before exposure.
• The patient and the operator must wear a protective apron before undergoing any kind of exposure. The apron should be made up of lead with thickness of 0.5mm.
• Specifically designed Lead-infused thyroid collar should be used by the patient to protect the thyroid gland from excessive radiation.
• In order to cover the reproductive organ of the patient Lead-infused leather or vinyl aprons should be used.
• The aprons should be checked regularly for any tear or cracks to minimise the chance of any risk.
• Excluding the patient and the operator, any third person in the room must stand behind a protective barrier.
• The apron should be stored and hung properly as any creases in the apron will generate a crack.
• The apron, gloves or any other items used in the radiation room must be removed in that specific room.
• Fast image receptors must be used for reducing the exposure level.
• The patient must use proper immobilization method.

Q2) List and describe at least five patient requirements that should be considered when taking a dental radiograph.

The requirement of the patient to be considered when taking a dental radiograph are explained as follows (Humanhealth.iaea.org 2019):

1. Age of the patient: Dental radiography is done for people of all ages including youngsters, adult and elder people. The sensitization level of the radiograph is different for different age of people, as the intensity of X-ray used for adults cannot be used for adolescent.
2. The current oral health problem: The doctor should have a clear idea of the patient’s problem so that the doctor can decide which type of radiography technique has to be used.

• Symptoms of Oral problem: This is the most important factor to be considered before taking up the dental radiography. The doctor should know exactly what kind of oral disease is the patient suffering.

1. History of gum or oral diseases: If the patient is suffering from any particular history of gum disease then the treatment approach will be different for such patients.
2. Safety measures of the patient: Proper safety measures should be explained to the patient before the patient takes up the dental radiograph.

Q3) Explain, using your own words how you would position an x-ray film to take a periapical x-ray of maxillary molars. Include in your answer a suggested film size, and what your x-ray will show. Once the x-ray has been taken, what steps do you take to label and mount the film?

X-ray film is placed over the palate. Initiate the process by dorsally placing the palate to the target teeth. Place the tube at 45-degree angle to the face. The X-ray film is positioned in the mouth diagonally from inside the maxillary teeth opposite to the side of the image location. Position the patient in such a way that the target teeth is on the top and parallel to the film hence, the positioning of the film and the teeth should be reproducible.

The suggested film size for taking a periapical X-ray of maxillary molars will be size 2 (31*41 mm) which is the standard size of the film (Choudhary et al. 2018). The X-ray report will show any kind of wear or failure of dental fillings and a detail view of the maxillary molar teeth from its crown to beyond the root where the teeth is attached to the jaw.

After X-ray has been taken, film mounting is done by placing the film in a supporter or holder with a raised bump to label the film. Once it is done radiograph is obtained which is analysed later.

Q4) What are the requirements for the operator when using the bisected angle technique? Include in your answer your understanding of using a periapical film holder.

Bisecting angle technique is used for taking periapical films and is used as an alternative method for performing periapical radiography (Sanghvi et al. 2018). The main requirements for the operator for using a bisecting angle technique is:

• Positioning of the patient- The patient should be positioned properly and should remove glasses or any kind of appliances. The patient should be provided with lead apron and thyroid collar.
• Film placement- Periapical film holder is used for either placing or supporting the film in the patient mouth. Periapical film holder helps the patient to avoid any kind of irradiation in their fingers if the patient is holding the film directly.
• Horizontal angulation- It is done by the operator with all his effort to place the film properly.
• Vertical angulation- Vertical angulation is done for both maxillary and mandibular teeth including both upper and lower teeth’s.
• Point of entry- The operator should decide the point of entry for the X-ray film using a periapical film holder.

Q5) What is the Radiation Act and Code of Practice for radiation protection in dentistry? Explain, in your own words, the main objective of the Act, who the Code applies to and the requirements for radiation protective measures.

Patient Requirements for Dental Radiography

Radiation act and code of practice for radiation protection is quoted in the Code of Practice for Radiation Protection in Dentistry (2005). The group members of Radiation Health Committee prepared this safety code. Radiation Health Committee established under the ARPANS act (1998) are responsible for making policies, preparation of draft which will include the code and basic standards for radiation protection (Arpansa.gov.au, 2019).

The main objective of the act was to prepare the code, which will establish different practices and procedures for the use of radiation in dentistry, which will have certain guidelines to be followed for reducing the risk of radiation exposure to the patient, the dentist and any other person involved in the process.

This Code is applied to the person who is responsible for the test and to the person carrying out or supporting the dental radiographic examination such as dentists, radiographers, dental counsellors, dental hygienists and dental supporters with prolonged responsibilities in dental training, and to the person who is supplying, repairing, and fixing or installing the dental X-ray equipment (Arpansa.gov.au, 2019). This is required to be sure that the patient and the operator are safely handling the radiation tool.

Q6) Explain how you would set up the radiographic imaging equipment for an OPG?

An Orthopantogram (OPG) gives a panoramic view of the lower face, all the teeth of the upper and lower jaw is displayed in a single film (Claudia et al. 2018). Teeth’s, which are not yet erupted or surfaced, are explained using this method. Any problem related to the jawbone or with the joint that fixes the jawbone with the head is revealed by an OPG. The radiographic imaging equipment is set for taking up the procedure when the patient is standing with his face relaxing on a minor shelf by biting mildly on a disinfected mouthpiece in order to make his head steady (Bijwaard et al. 2018). The correct positioning of the patient is the most important criteria for setting up the radiographic imaging in OPG with head and neck straight. Three beams of light is required for this process which includes mid saggital, canine position and Frankfort. A correct orientation of the labelled cassettes should be placed with the tube of the cassettes facing the patient.

Q7) List and briefly explain different processing procedures for wet processing?

The different radiography processing techniques used for processing are describes as follows (Humanhealth.iaea.org 2019):

• Exposure- In this method latent image is created. Deposits of the free or ionized silver ions that is not detected by any known physical test create latent image.The free silver ions remain attached on the X-ray film by the time it is changed to a visible silver image through chemical processing method (Ibrahim 2018).
• Development- Development is defined as the chemical process, which intensifies the latent image to an observable silver pattern. In this process, a chemical solution known as developer is used (AgBr + X-ray photons = Ag+ + Br-).
• Rinsing- A mild and continuous rinsing is required after developing process. The rinsing will take place in water for 30 seconds in order to remove any kind of alkali activators.
• Fixing- Fixing is done to toughened the film emulsion by using a chemical solution known as fixer.
• Washing- It is considered as an important step because this process removes all the leftover chemicals present in the emulsions.
• Drying- Before mounting and viewing the film, it must be air-dried in a dust-restricted area under room temperature.

Q8) How do you ensure quality assurance measures for exposed dental radiographs. List three possible errors that may affect the quality of the x-ray?

Quality assurance is the most important factor for any kind of exposure with dental radiography. The quality assurance procedures for conventional and digital radiography are as follow (Zenobio et al. 2018):

• Comparison of radiographs with the x-ray film used.
• Replace the processing solution, which is used for a longer time.
• Proper and routine temperature checks should be done for processing solution.
• Routine visual inspection of the wiring and casing in case of CCDs/ CMOS should be done.
• Visual inspection of any scratches in the aprons or lead collar should be done on a regular basis.
• The exposure chart should be checked properly with calibration of the X-ray machine.

The possible errors that may affect the quality of the X-ray are classified into three different groups (Rockenbach, Morosolli and Dias 2018):

1. Technique and projection error- This error includes the patient positioning error and the improper film placement error.
2. Exposure error- This includes the error caused due to the inappropriate exposure, which leads to blank image, low-density image and high-density image.

• Processing error- This includes the chemical and the film handling errors while conducting the process of dental radiograph.

References:

Arpansa.gov.au 2019. [online] Arpansa.gov.au. Available at: https://www.arpansa.gov.au/sites/default/files/legacy/pubs/rps/rps10.pdf [Accessed 19 Feb. 2019].

Bijwaard, H., Scheurleer, J., Roding, T. and de Vries, G., 2018. Digital imaging and radiographic practise in diagnostic radiography: An overview of current knowledge and practice in Europe.

Choudhary, S.H., Kale, L.M., Mishra, S.S., Supe, N.B., Zaidi, N.S. and Pandey, N.D., 2018. Modified occlusal technique using intraoral periapical film: An alternative approach. Journal of Indian Academy of Oral Medicine and Radiology, 30(2), p.193

Claudia, A., Barbu, H.M., Adi, L., Gultekin, A., Reiser, V., Gultekin, P. and Mijiritsky, E., 2018. Relationship between third mandibular molar angulation and distal cervical caries in the second molar. Journal of Craniofacial Surgery, 29(8), pp.2267-2271.

Humanhealth.iaea.org 2019. [online] Humanhealth.iaea.org. Available at: https://humanhealth.iaea.org/HHW/MedicalPhysics/TheMedicalPhysicist/Studentscorner/HandbookforTeachersandStudents/Chapter_10.pdf [Accessed 20 Feb. 2019].

Ibrahim, F., 2018. Assessment of Knowledge of Occupational Health Hazards and Safety Practices among Radiographers in the Greater Accra Region, Ghana (Doctoral dissertation, University of Ghana).

Rockenbach, M.I.B., Morosolli, A.R.C. and Dias, V.S.C., 2018. Periapical radiographic technique errors made with digital sensors. Journal of Pharmaceutical and Biological Sciences.

Sanghvi, S., Rao, A., Karuna, Y.M., Shetty, K. and Nayak, A., 2018. Image Distortion of the Roots of Maxillary Deciduous Molars on Iopa’s Recorded with Bisecting Angle or a Modified Paralleling Technique. Biomedical & Pharmacology Journal, 11(2), p.1039.

Zenóbio, E.G., Zenóbio, M.A., Azevedo, C.D., Nogueira, M.D.S., Almeida, C.D. and Manzi, F.R., 2018. Assessment of image quality and exposure parameters of an intraoral portable X-rays device. Dentomaxillofacial Radiology, 47(xxxx), p.20180329