What is a clinical method to decrease the object-to-receptor distance?

• A. Increase exposure time
• B. Place the receptor close to tooth
• C. Use a larger receptor
• D. Move the receptor farther from the tooth

Answer: (B)

Decreasing the object-to-receptor distance improves image sharpness and reduces magnification in dental radiography. The practical way to achieve this is to place the receptor as close to the tooth as possible, with the receptor positioned parallel to the tooth and the x-ray beam perpendicular to both. Increasing exposure time changes brightness and dose but not geometry. Using a larger receptor does not shorten the gap, and moving the receptor farther away increases the distance and magnification. So, placing the receptor close to the tooth is the effective method.