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. Panoramic imaging is done to visualize the status of impacted tooth. This type of imaging technique uses:
Diagnostic imaging with projection radiography and computed tomography use X-rays, a category of electromagnetic radiation that is ionizing in nature. 
Magnetic resonance imaging uses electromagnetic radiations of significantly lower energies than X-rays and at energies that are non-ionizing. 
High-energy electromagnetic radiations (gamma rays, γ) and high-energy particulate radiations (electron beams and protons) are used in cancer therapy. 
Reference: ORAL RADIOLOGY PRINCIPLES AND INTERPRETATION,8th EDITION, Stuart C. White,Michael J. Pharoah
Electromagnetic radiations which are ionizing in nature
Electromagnetic radiations which are non-ionizing in nature
High energy particulate radiations which are ionizing in nature
High energy particulate radiations which are non-ionizing in nature