Porcelain braces should be the correct term for metal porcelain crowns, metal porcelain crowns within the tooth pain is generally caused by cementum dissolution, pulpitis, occlusal trauma, etc., the treatment methods were reclosed, root canal treatment, adjusting the grinding change, as follows. 1. Reclosure: the cementum is dissolved, the edge of the metal porcelain crown loses its sealing effect, which may lead to the loosening of the restoration to produce mechanical stimulation of the dentin to cause toothache, and should be added to the cementum material to re-closure of the edge of the metal porcelain crown. 2. Root canal therapy: spontaneous pain caused by pulpitis, after a clear diagnosis can be removed from the metal porcelain crown root canal therapy, if you need the original porcelain crown to maintain the aesthetic and functional, can be punched in the porcelain crown for endodontic treatment, to be endodontic treatment is completed after the removal of the original crown to be made again. 3. Fitting and grinding: toothache caused by occlusal trauma can be relieved by fitting and grinding. There may be other reasons for toothache in metal porcelain crowns, so it is recommended to go to the hospital in time.