According to federal regulations, dental x-rays must be collimated to what maximum size?

The correct answer is based on the regulations that aim to minimize patient exposure to radiation. Federal guidelines, specifically those set by the National Council on Radiation Protection and Measurements (NCRP), dictate that dental x-rays should be collimated to a maximum size of 2.75 inches for adult patients. This size ensures that the x-ray beam is adequately focused on the area of interest while reducing unnecessary exposure to surrounding tissues.

Collimation is a crucial practice in radiology to improve image quality and enhance safety by limiting the area exposed to radiation. In dental radiography, adhering to the 2.75-inch collimation requirement helps maintain compliance with safety standards and reflects best practices in radiation protection.

Other sizes mentioned are not aligned with the established federal regulations, which specify that 2.75 inches is the maximum allowable size for dental x-ray collimation in adults.