title: Clinical performance of provisional screw-retained metal-free acrylic restorations in an immediate loading implant protocol: a 242 consecutive patients' report.
abstract: OBJECTIVE
  To evaluate the clinical performance of provisional screw-retained metal-free acrylic restorations in an immediate loading implant protocol.
  
  
  METHODS
  Two hundred and forty-two consecutive patients were selected retrospectively, who received 1011 implants and 311 immediate provisional screw-retained implant restorations (2-4 h after implant surgery). The patients were monitored for a period of 2-3 months, until they were referred for a final restoration. The primary variables recorded include the survival time and the appearance of fractures in the provisional restoration, and the independent variables included age, sex, dental arch, type of restoration, type of attachment and components used, as well as cantilevers and opposing dentition. A survival analysis (Kaplan-Meier) and a Cox regression analysis were performed.
  
  
  RESULTS
  Twenty-three restorations in 20 patients (8.26%, 95% CI 4.8-11.7) showed at least one fracture (7.39%). More than half of the new fractures (52%, 12 cases) occurred in the first 4 weeks. The cumulative survival probability observed was greater in mandible (P=0.05) and non-cantilever restorations (P=0.001), and in those opposed by full restorations or natural teeth (P=0.001). With an opposing implant-supported prosthesis, the risk of fracture was multiplied by 4.7, and the use of cantilevers as well as the location of the restoration in the maxilla multiply the risk by 3.4-3.5.
  
  
  CONCLUSIONS
  Immediate provisional screw-retained metal-free implant-supported restorations can be considered a reliable restoration (92.6% remain intact) for the healing period of 3 months.
authors.affiliation: Section of Periodontology, Faculty of Dentistry and Medicine, University of Oviedo, Oviedo, Spain.
authors.forename: Jose-María
authors.initials: JM
authors.lastname: Suarez-Feito
authors.forename: Alberto
authors.initials: A
authors.lastname: Sicilia
authors.forename: Jorge
authors.initials: J
authors.lastname: Angulo
authors.forename: Subir
authors.initials: S
authors.lastname: Banerji
authors.forename: Isabel
authors.initials: I
authors.lastname: Cuesta
authors.forename: Brian
authors.initials: B
authors.lastname: Millar
mesh_terms: D000180:Acrylic Resins; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D015921:Dental Implants; D017268:Dental Prosthesis Retention / Q000295:instrumentation*; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003794:Dental Restoration, Temporary; D003799:Dental Stress Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D003765:Models, Dental; D016016:Proportional Hazards Models; D016896:Treatment Outcome
chemical_list: D000180:Acrylic Resins; D015921:Dental Implants