title: Computer-assisted design/computer-assisted manufacturing zirconia implant fixed complete prostheses: clinical results and technical complications up to 4 years of function.
abstract: OBJECTIVE
  To report the clinical results and technical complications with computer-assisted design/computer-assisted manufacturing (CAD/CAM) zirconia, implant fixed complete dental prostheses (IFCDPs) after 2-4 years in function.
  
  
  METHODS
  Fourteen consecutive edentulous patients (16 edentulous arches) were included in this study. Ten of the patients were women and four were men, with an average age of 58 years (range: 35-71). Ten mandibular and six maxillary arches were restored with porcelain fused to zirconia (PFZ) IFCDPs. Of the 16 arches, 14 received one-piece and 2 received segmented two-piece IFCDPs, respectively. The mean clinical follow-up period was 3 years (range: 2-4). At the last recall appointment, biological and technical parameters of dental implant treatment were evaluated.
  
  
  RESULTS
  The implant and prosthesis survival rate following prosthesis insertion was 100% up to 4-year follow-up. The prostheses in 11 of the 16 restored arches were structurally sound, exhibited favorable soft tissue response, esthetics, and patient satisfaction. Five IFCDPs (31.25%) in four patients exhibited porcelain veneer chipping. Chipping was minor in three prostheses (three patients) and was addressed intraorally with polishing (one prosthesis) or composite resin (two prostheses). One patient with maxillary and mandibular zirconia IFCDP exhibited major porcelain chipping fractures which had to be repaired in the laboratory. Function, esthetics, and patient satisfaction were not affected in three of the four fracture incidents. Median crestal bone loss was 0.1 mm (0.01-0.2 mm). The presence of parafunctional activity, the IFCDP as opposing dentition, and the absence of occlusal night guard were associated with all the incidents of ceramic chipping.
  
  
  CONCLUSIONS
  CAD/CAM zirconia IFCDPs are viable prosthetic treatment after 2-4 years in function, but not without complications. The porcelain chipping/fracture was the most frequent technical complication, with a 31.25% chipping rate at the prosthesis level. Despite the technical complications, increased patient satisfaction was noted.
authors.affiliation: Division of Prosthodontics, Columbia University College of Dental Medicine, New York, NY 10032, USA. pp2229@columbia.edu
authors.forename: Panos
authors.initials: P
authors.lastname: Papaspyridakos
authors.forename: Kunal
authors.initials: K
authors.lastname: Lal
mesh_terms: D000328:Adult; D000368:Aged; D017076:Computer-Aided Design; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003824:Denture, Complete; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D011861:Radiography, Dental; D018570:Risk Assessment; D012307:Risk Factors; D012984:Software; D015996:Survival Rate; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide