X-rays are taken when necessary to perform a dental procedure. For example, with a crown, the standard is that an x-ray be taken immediately prior to the procedure to confirm the tooth is still healthy. This is because e.g. infections can exist without any symptoms. After the procedure, an x-ray is taken to confirm that the crown is properly seated. These standards are established by state regulatory agencies, insurance companies and professional associations. If you have any additional questions and concerns, please feel free to speak to a clinical team member or the doctor.