Size of the bur for preparing lingual rest seat for a RPD is: (A) 1/10 inch, (B) 1/4 inch, (C) 1/2 inch, (D) 1 inch
Answer is B. To prepare the lingual rest in enamel, a safe side 1/4 inch diamond disk should be used.
Occlusal rest seats in sound enamel may be prepared with diamond points of approximately the size of No. 6 and round burs.