What is the function of a prophy angle in dental procedures?

The function of a prophy angle in dental procedures is specifically designed for polishing teeth using a prophy cup. A prophy angle attaches to the dental handpiece and holds a rubber or soft prophy cup that is filled with a polishing paste. When the prophy angle is activated, it rotates the cup, allowing it to effectively smooth and polish the surfaces of the teeth. This polishing process is important for removing plaque, surface stains, and preventing dental caries by creating a smoother surface on the teeth where bacteria are less likely to adhere.

The other choices do not accurately describe the function of a prophy angle. Extracting teeth requires different specialized instruments, applying local anesthetic involves syringes and specific techniques, and removing calculus typically uses hand instruments such as scalers or ultrasonic devices rather than a prophy angle. Thus, polishing teeth with a prophy cup is the correct and primary function of this dental tool.