BDA Radiography Exam – Dental Radiography Certification Study Guide & Practice Review
What are X-rays classified as in terms of radiation? - (ANSWER)X-rays are classified as ionising radiation.
What is the difference between X-rays and gamma rays? - (ANSWER)Gamma rays are naturally
occurring, while X-rays are man-made.
What are the four main ways X-ray photons can interact with matter? - (ANSWER)1. Transmission - pass
through matter without interaction. 2. Absorption - all energy is absorbed by matter.
3. Absorption and Scatter - deflected with energy loss.
4. Pure Scatter - deflected with no energy loss.
What are tissue reaction effects in the context of ionising radiation? - (ANSWER)Tissue reaction effects
(somatic, deterministic effects) result from high doses of radiation, where the severity of damage is
proportional to the dose.
What are stochastic effects of ionising radiation? - (ANSWER)Stochastic effects are chance effects that
can occur from any dose of radiation, with severity not related to the dose. A single X-ray photon can
potentially cause fatal cancer.
What is the main aim of radiation protection in dental radiography? - (ANSWER)To completely prevent
deterministic effects and limit the chances of stochastic effects to an acceptable level.
What is the nature of X-rays? - (ANSWER)X-rays are packets of energy called photons that travel in
straight lines and can travel in a vacuum.
How do X-rays interact with film emulsion? - (ANSWER)X-rays can blacken film emulsion to create an
image.
What is the significance of the phrase 'there is no such thing as a safe dose of radiation'? - (ANSWER)It
emphasizes that any exposure to radiation carries some level of risk.
,BDA Radiography Exam – Dental Radiography Certification Study Guide & Practice Review
What are the characteristics of X-ray photons? - (ANSWER)X-ray photons have a short wavelength and
high energy, originating and interacting at the atomic level.
What are the genetic effects of ionising radiation? - (ANSWER)Genetic effects occur in reproductive cells
(egg and sperm) and may affect future offspring.
What is the relationship between radiation dose and stochastic effects? - (ANSWER)Increasing the
radiation dose increases the chance of stochastic damage occurring.
What is the significance of the term 'ionising radiation'? - (ANSWER)Ionising radiation has enough
energy to remove tightly bound electrons from atoms, which can lead to tissue damage.
What is the potential risk associated with a single X-ray photon? - (ANSWER)Although very unlikely, it
has the potential to cause fatal cancer.
What is the role of physical methods in radiation protection? - (ANSWER)Physical methods are used to
reduce the level of risk involved with radiation exposure.
What is the nature of photons in the electromagnetic spectrum? - (ANSWER)Photons come in a wide
range of energies, with very low energy making up radio waves and medium energy visible as light.
What is the importance of understanding atomic interactions in X-ray production? -
(ANSWER)Understanding atomic interactions is crucial for explaining how X-rays are produced.
What are the basic features of dental X-ray generating equipment? - (ANSWER)Dental X-ray equipment
includes components like the tubehead, X-ray tube, step-up transformer, oil for heat removal, and a
spacer cone for aiming the beam.
What is the relevance of current recommendations and regulations concerning X-ray equipment? -
(ANSWER)Regulations ensure safety and effectiveness in X-ray usage, including specifications for
equipment design, operation, and exposure limits.
,BDA Radiography Exam – Dental Radiography Certification Study Guide & Practice Review
How do exposure variables kV, mA, and time affect dental X-ray images? - (ANSWER)kV controls the
energy and penetrating power of X-ray photons; mA and time control the quantity of X-ray photons
produced, affecting film blackening.
What is the effect of increasing kV on the contrast of a radiographic image? - (ANSWER)Increasing kV
decreases the contrast between light and dark parts of the radiographic image, summarized as 'kV kills
contrast'.
What happens to low-energy X-ray photons in the body? - (ANSWER)Low-energy X-ray photons tend to
be absorbed by soft tissues, which can cause damage.
What is the advantage of high-energy X-ray photons? - (ANSWER)High-energy X-ray photons pass
through soft tissues and hit the film, making them more diagnostically useful.
How can the most harmful, lowest-energy X-ray photons be removed? - (ANSWER)They can be removed
by passing the beam through an aluminium filter.
What is the function of the X-ray tube in dental X-ray equipment? - (ANSWER)The X-ray tube is a small
glass vacuum tube where X-rays are produced, containing a cathode and a tungsten target.
What role does the step-up transformer play in X-ray equipment? - (ANSWER)It converts ordinary mains
voltage (240V) to the high voltage (70,000V or 70kV) required to produce X-rays.
Why is oil used in the tubehead of X-ray equipment? - (ANSWER)Oil helps remove heat produced during
an exposure.
What is the process of X-ray production in dental equipment? - (ANSWER)X-rays are created when high-
speed electrons collide with the tungsten target in the X-ray tube.
What determines the overall energy of the X-ray photons produced? - (ANSWER)The overall energy
depends on the speed of the electrons, which is determined by the size of the high voltage 'push' or 'kV'.
, BDA Radiography Exam – Dental Radiography Certification Study Guide & Practice Review
What is the efficiency of the X-ray production process? - (ANSWER)The process is very inefficient, with
only 1% of the electrons' energy converted into X-rays; the rest is converted to heat.
What are the operating ranges for kV in dental X-ray equipment? - (ANSWER)The operating range is
typically between 60-70kV.
What thickness of aluminium filter is required for X-ray sets under 70kV? - (ANSWER)A 1.5mm thick
aluminium filter is required for X-ray sets under 70kV.
What thickness of aluminium filter is required for X-ray sets over 70kV? - (ANSWER)A 2.5mm thick
aluminium filter is required for X-ray sets over 70kV.
What are somatic stochastic effects of X-ray exposure? - (ANSWER)Somatic stochastic effects are
random effects that can occur from radiation exposure, such as cancer, with no safe dose.
What is indirect damage caused by X-rays? - (ANSWER)Indirect damage occurs when X-ray photons
ionize other molecules, like water, producing toxic substances such as hydrogen peroxide.
What are the potential consequences of high doses of radiation? - (ANSWER)High doses can cause
severe damage or even death, but typical dental radiation doses are not high enough for deterministic
effects.
What is the main concern regarding radiation doses used in dentistry? - (ANSWER)The main concern is
somatic stochastic effects, as even small doses can potentially lead to fatal cancer.
What is the function of a spacer cone in dental X-ray equipment? - (ANSWER)The spacer cone is used to
aim the X-ray beam accurately.
What is the maximum diameter for circular collimators in dental X-ray equipment? - (ANSWER)The
maximum diameter for circular collimators is 60mm.
What are X-rays classified as in terms of radiation? - (ANSWER)X-rays are classified as ionising radiation.
What is the difference between X-rays and gamma rays? - (ANSWER)Gamma rays are naturally
occurring, while X-rays are man-made.
What are the four main ways X-ray photons can interact with matter? - (ANSWER)1. Transmission - pass
through matter without interaction. 2. Absorption - all energy is absorbed by matter.
3. Absorption and Scatter - deflected with energy loss.
4. Pure Scatter - deflected with no energy loss.
What are tissue reaction effects in the context of ionising radiation? - (ANSWER)Tissue reaction effects
(somatic, deterministic effects) result from high doses of radiation, where the severity of damage is
proportional to the dose.
What are stochastic effects of ionising radiation? - (ANSWER)Stochastic effects are chance effects that
can occur from any dose of radiation, with severity not related to the dose. A single X-ray photon can
potentially cause fatal cancer.
What is the main aim of radiation protection in dental radiography? - (ANSWER)To completely prevent
deterministic effects and limit the chances of stochastic effects to an acceptable level.
What is the nature of X-rays? - (ANSWER)X-rays are packets of energy called photons that travel in
straight lines and can travel in a vacuum.
How do X-rays interact with film emulsion? - (ANSWER)X-rays can blacken film emulsion to create an
image.
What is the significance of the phrase 'there is no such thing as a safe dose of radiation'? - (ANSWER)It
emphasizes that any exposure to radiation carries some level of risk.
,BDA Radiography Exam – Dental Radiography Certification Study Guide & Practice Review
What are the characteristics of X-ray photons? - (ANSWER)X-ray photons have a short wavelength and
high energy, originating and interacting at the atomic level.
What are the genetic effects of ionising radiation? - (ANSWER)Genetic effects occur in reproductive cells
(egg and sperm) and may affect future offspring.
What is the relationship between radiation dose and stochastic effects? - (ANSWER)Increasing the
radiation dose increases the chance of stochastic damage occurring.
What is the significance of the term 'ionising radiation'? - (ANSWER)Ionising radiation has enough
energy to remove tightly bound electrons from atoms, which can lead to tissue damage.
What is the potential risk associated with a single X-ray photon? - (ANSWER)Although very unlikely, it
has the potential to cause fatal cancer.
What is the role of physical methods in radiation protection? - (ANSWER)Physical methods are used to
reduce the level of risk involved with radiation exposure.
What is the nature of photons in the electromagnetic spectrum? - (ANSWER)Photons come in a wide
range of energies, with very low energy making up radio waves and medium energy visible as light.
What is the importance of understanding atomic interactions in X-ray production? -
(ANSWER)Understanding atomic interactions is crucial for explaining how X-rays are produced.
What are the basic features of dental X-ray generating equipment? - (ANSWER)Dental X-ray equipment
includes components like the tubehead, X-ray tube, step-up transformer, oil for heat removal, and a
spacer cone for aiming the beam.
What is the relevance of current recommendations and regulations concerning X-ray equipment? -
(ANSWER)Regulations ensure safety and effectiveness in X-ray usage, including specifications for
equipment design, operation, and exposure limits.
,BDA Radiography Exam – Dental Radiography Certification Study Guide & Practice Review
How do exposure variables kV, mA, and time affect dental X-ray images? - (ANSWER)kV controls the
energy and penetrating power of X-ray photons; mA and time control the quantity of X-ray photons
produced, affecting film blackening.
What is the effect of increasing kV on the contrast of a radiographic image? - (ANSWER)Increasing kV
decreases the contrast between light and dark parts of the radiographic image, summarized as 'kV kills
contrast'.
What happens to low-energy X-ray photons in the body? - (ANSWER)Low-energy X-ray photons tend to
be absorbed by soft tissues, which can cause damage.
What is the advantage of high-energy X-ray photons? - (ANSWER)High-energy X-ray photons pass
through soft tissues and hit the film, making them more diagnostically useful.
How can the most harmful, lowest-energy X-ray photons be removed? - (ANSWER)They can be removed
by passing the beam through an aluminium filter.
What is the function of the X-ray tube in dental X-ray equipment? - (ANSWER)The X-ray tube is a small
glass vacuum tube where X-rays are produced, containing a cathode and a tungsten target.
What role does the step-up transformer play in X-ray equipment? - (ANSWER)It converts ordinary mains
voltage (240V) to the high voltage (70,000V or 70kV) required to produce X-rays.
Why is oil used in the tubehead of X-ray equipment? - (ANSWER)Oil helps remove heat produced during
an exposure.
What is the process of X-ray production in dental equipment? - (ANSWER)X-rays are created when high-
speed electrons collide with the tungsten target in the X-ray tube.
What determines the overall energy of the X-ray photons produced? - (ANSWER)The overall energy
depends on the speed of the electrons, which is determined by the size of the high voltage 'push' or 'kV'.
, BDA Radiography Exam – Dental Radiography Certification Study Guide & Practice Review
What is the efficiency of the X-ray production process? - (ANSWER)The process is very inefficient, with
only 1% of the electrons' energy converted into X-rays; the rest is converted to heat.
What are the operating ranges for kV in dental X-ray equipment? - (ANSWER)The operating range is
typically between 60-70kV.
What thickness of aluminium filter is required for X-ray sets under 70kV? - (ANSWER)A 1.5mm thick
aluminium filter is required for X-ray sets under 70kV.
What thickness of aluminium filter is required for X-ray sets over 70kV? - (ANSWER)A 2.5mm thick
aluminium filter is required for X-ray sets over 70kV.
What are somatic stochastic effects of X-ray exposure? - (ANSWER)Somatic stochastic effects are
random effects that can occur from radiation exposure, such as cancer, with no safe dose.
What is indirect damage caused by X-rays? - (ANSWER)Indirect damage occurs when X-ray photons
ionize other molecules, like water, producing toxic substances such as hydrogen peroxide.
What are the potential consequences of high doses of radiation? - (ANSWER)High doses can cause
severe damage or even death, but typical dental radiation doses are not high enough for deterministic
effects.
What is the main concern regarding radiation doses used in dentistry? - (ANSWER)The main concern is
somatic stochastic effects, as even small doses can potentially lead to fatal cancer.
What is the function of a spacer cone in dental X-ray equipment? - (ANSWER)The spacer cone is used to
aim the X-ray beam accurately.
What is the maximum diameter for circular collimators in dental X-ray equipment? - (ANSWER)The
maximum diameter for circular collimators is 60mm.
