Objective To discuss the unsuccessful reasons and the preventive methods of the unsuccessful clinic cases.Meth- ods The retrospective analysiswas carried on the 80 prosthesis in 70 patients from 1994 to 2001 whichwere sufferedwith unsuc- cessful results after the restoration of the metal crowns and bridges.Results Therewere 68 teethwhich had collapsed or broken. 20 teeth had the post loosing or shedding. Root breaking, food impaction, unharmony colors of porcelain and the changing color of gingival were 3,3,6 and 2 teeth.Conclusion It is necessary to select suitable repairing materials and operate correctly for pre- venting the occurring of the unsuccessful results in the porcelain-fused-to-metal-corwns and bridges.
