A 26 year old male presented to the dental clinic with pain in the right lower back tooth region. On examination, it was evident that pericoronitis is present with #48. The inherent filtration of the machine used is 3 mm of Aluminium operating at 70 kVp. By the use of this machine, the surface exposure:

Filtration results in decreased patient exposure with no loss of radiographic information.   When an X-ray beam is filtered with 3 mm of aluminum, the surface exposure is reduced to approximately 20% of the exposure with no filtration.   Reference: ORAL RADIOLOGY PRINCIPLES AND INTERPRETATION,8th EDITION, Stuart C. White,Michael J. Pharoah