Final answer:
In a pulpotomy, a high-speed handpiece is used to remove the coronal portion of the pulp to treat decay that has reached the pulp but not the root.
Step-by-step explanation:
During a pulpotomy, the coronal portion of the pulp is removed with a high-speed handpiece. This dental procedure is typically used to treat tooth decay that has extended to the pulp but has not yet infected the root. The purpose of a pulpotomy is to remove the affected pulp tissue, disinfect the area, and preserve the remaining healthy pulp and tooth structure. A high-speed handpiece is preferred because it allows for precise removal of the diseased tissue quickly and effectively, while minimizing damage to the surrounding tooth structure.