title: Veneer fracture in implant-supported metal-ceramic restorations. Part I: Overall success rate and impact of occlusal guidance.
abstract: OBJECTIVE
  The aims of the presented study were to define the fracture rate of implant-supported metal-ceramic restorations delivered in private practice, and to identify if a restoration's contact during eccentric mandible movements has any influence on ceramic fracture rates.
  
  
  METHODS
  Within the period from 2005 to 2008, 251 patients, namely 105 men (42%) and 146 women (58%), received 775 dental implants which later were restored with metal-ceramic restorations. Data was gathered and analyzed in the form of a specially-designed electronic questionnaire. In total, 251 patients were rehabilitated with 350 prostheses consisting of 151 single crowns, 208 fixed partial dentures of various extents and 21 full-arch restorations. The method for retention of prostheses included cement-, screw-, or hybrid cement-screw retained prosthetic devices. The patients were recalled and examined for the presence of mechanical complications, namely ceramic fractures. Fractures were distinguished as adhesive or co-adhesive. The follow-up time was registered.
  
  
  RESULTS
  The mean ceramic fracture rate was 6.7%, as fracture occurred in 24 restorations. In the single crown group, the fracture rate was 1.3%, in the fixed partial denture division it was 6.7%, and the full-arch metal-ceramic restorations experienced 38.1% chipping. The mean follow-up period of prostheses was 9.5 months, ranging from 1 to 42 months. The analysis revealed that 66 prostheses had contact in protrusive and/or lateral mandibular movements, constituting 17.4% of all restorations; while 13 restorations had ceramic fractures, composing 19.7% of all guiding prostheses.
  
  
  CONCLUSIONS
  Within the limitations of this trial, it can be noted that ceramic veneer fracture rate was 6.7% in 380 restorations, and a conclusion that a restoration's contact during eccentric excursions may significantly enlarge fracture rates can be made.
authors.affiliation: Institute of Odontology, Faculty of Medicine, Vilnius University, Zalgirio str. 115, LT-08217, Vilnius, Lithuania. linktomo@gmail.com
authors.forename: Tomas
authors.initials: T
authors.lastname: Linkevicius
authors.forename: Eugenijus
authors.initials: E
authors.lastname: Vladimirovas
authors.forename: Simonas
authors.initials: S
authors.lastname: Grybauskas
authors.forename: Algirdas
authors.initials: A
authors.lastname: Puisys
authors.forename: Vygandas
authors.initials: V
authors.lastname: Rutkunas
mesh_terms: D000328:Adult; D000368:Aged; D003442:Crowns; D003766:Dental Occlusion; D017268:Dental Prosthesis Retention / Q000379:methods; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003801:Dental Veneers; D003824:Denture, Complete; D003830:Denture, Partial, Fixed; D005260:Female; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys; D008875:Middle Aged; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D016876:Metal Ceramic Alloys