What is the minimum total aluminum filtration required for dental x-ray machines operating above 70 kVp?

Dental x-ray machines that operate above 70 kVp are required to have a minimum total aluminum filtration of 2.5 mm. This regulation is in place to ensure the safety and effective use of radiography equipment. Filtration serves to reduce the amount of low-energy radiation produced, which is less useful for imaging and contributes to unnecessary radiation exposure for patients.

Higher energies in the x-ray beam generally require more filtration to adequately remove these lower-energy photons while allowing higher-energy, more penetrating photons to pass through. Since x-ray machines operating at this higher voltage produce more penetrating X-rays, the requirement for increased filtration ensures that the patient is exposed only to the necessary dose to achieve diagnostic quality images. This standard was established based on research that balances image quality and patient safety, making the use of 2.5 mm of aluminum the minimum requirement for such equipment.