An oral examination and oral x-rays are required when the back teeth are empty. If x-rays show a large crown defect but the pulp floor is intact, a digging spoon can be used to scrape away large pieces of decay, carefully search for the root canal opening, extract the infected and necrotic pulp, thoroughly rinse and disinfect the root canal, complete the root canal filling, utilize one or two of the root canals to fabricate a stump core for fixation, and then complete a porcelain or all-porcelain crown restoration. If X-rays show perforation of the pulp chamber floor of the molar and separation of the roots, the root with lesions at the root tip can be extracted, the robust residual root can be retained, and after completing the root canal treatment, the tooth can be prepared together with the neighboring teeth to fabricate a joint crown restoration. If the posterior teeth have been loosened and recurrent infections have occurred, they can be extracted under local anesthesia and then restored at a later date.