A tooth is bad to do a few porcelain teeth, depending on the degree of damage to the affected tooth and the size of the retention force may do one or three porcelain teeth. 1. Do a porcelain tooth: general dental caries do root canal treatment, need to do pile core crown repair, dental defects less generally do a crown can achieve the requirements of retention. 2. Do two to three porcelain teeth: when the affected tooth after root canal treatment if the crown is too short enough to place a crown is recommended to add a crown to enhance the retention force. If the tooth is damaged to the extent that it needs to be extracted, making a porcelain tooth restoration requires the neighboring teeth on both sides to be the abutment, and three crowns are needed at this time. Dental implants can also be considered at this time. A broken tooth to do a few porcelain teeth specific need to go to the hospital to check according to the degree of damage to the teeth to determine.