title: Catastrophic failure of a monolithic zirconia prosthesis.
abstract: Recently, monolithic zirconia restorations have received attention as an alternative to zirconia veneered with feldspathic porcelain to eliminate chipping failures of veneer ceramics. In this clinical report, a patient with mandibular edentulism received 4 dental implants in the interforaminal area, and a screw-retained monolithic zirconia prosthesis was fabricated. The patient also received a maxillary complete removable dental prosthesis over 4 anterior roots. At the 18-month follow-up, all of the zirconia cylinders were seen to be fractured, and the contacting abutment surfaces had lost structural integrity. The damaged abutments were replaced with new abutments, and a new prosthesis was delivered with a computer-assisted design and computer-assisted manufacturing fabricated titanium framework with denture teeth and denture base resins. At the 6-month recall, the patient did not have any problems. Dental zirconia has excellent physical properties; however, care should be taken to prevent excessive stresses on the zirconia cylinders when a screw-retained zirconia restoration is planned as a definitive prosthesis.
authors.affiliation: Clinical Assistant Professor, Department of Dentistry, Yong-In Severance Hospital, College of Medicine, Yonsei University, Yong-In, Korea.
authors.forename: Jae-Seung
authors.initials: JS
authors.lastname: Chang
authors.affiliation: Graduate student, Department of Prosthodontics, Gangnam Severance Dental Hospital, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Woon
authors.initials: W
authors.lastname: Ji
authors.affiliation: Graduate student, Department of Prosthodontics, Gangnam Severance Dental Hospital, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Choi
authors.affiliation: Associate Professor and Chairman, Department of Prosthodontics, Gangnam Severance Dental Hospital, College of Dentistry, Yonsei University, Seoul, Korea. Electronic address: sunjai@yuhs.ac.
authors.forename: Sunjai
authors.initials: S
authors.lastname: Kim
mesh_terms: D000368:Aged; D003188:Composite Resins / Q000737:chemistry; D017076:Computer-Aided Design; D059605:Dental Implant-Abutment Design; D003764:Dental Materials / Q000737:chemistry*; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003819:Denture Bases; D003779:Denture Design; D003826:Denture, Complete, Lower; D003828:Denture, Overlay; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019233:Retreatment; D014025:Titanium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide