What is the primary purpose of the collimator in intraoral radiography?

What is the primary purpose of the collimator in intraoral radiography?

• A. Increase exposure
• B. Focus the beam
• C. Restrict beam diameter
• D. Increase beam energy

Answer: (C)

The main idea is beam restriction. The collimator shapes and limits the x-ray beam so it only covers the size of the dental receptor being used. By restricting beam diameter in intraoral radiography, you minimize radiation to surrounding tissues, reduce off‑axis exposure, and cut down on scatter that can fog the image. The collimator doesn’t focus the beam, increase exposure, or raise energy—it simply narrows the field that is irradiated. That’s why restricting beam diameter is the best answer.

The main idea is beam restriction. The collimator shapes and limits the x-ray beam so it only covers the size of the dental receptor being used. By restricting beam diameter in intraoral radiography, you minimize radiation to surrounding tissues, reduce off‑axis exposure, and cut down on scatter that can fog the image. The collimator doesn’t focus the beam, increase exposure, or raise energy—it simply narrows the field that is irradiated. That’s why restricting beam diameter is the best answer.