Oral radiographs should be taken and pulp vitality tests performed when a cavity in a tooth is large. If the cavity is close to the pulp cavity and the pulp vitality is normal, you can use a spatula to scrape away the large pieces of decayed material, switch to a low-speed ball drill to slowly remove the decayed tooth tissue, place calcium hydroxide near the pulp for cushioning, use clove oil and zinc oxide to temporarily close the cavity, and observe the cavity for 1-2 weeks, and then proceed to filling and repairing when the tooth is not in severe pain. If the tooth keeps aching and the X-ray shows that the pulp angle is exposed in the cavity, it is necessary to remove the pulp under local anesthesia, complete the root canal treatment, and fabricate the inlay and full crown restoration to avoid splitting the tooth. If the X-ray shows that the cavity destroys the pulp chamber floor and the root is separated, the tooth needs to be extracted and then restored.