title: 5-year follow-up of a prospective clinical study on various types of core restorations.
abstract: OBJECTIVE
  This study tested whether: (1) the survival rate of cast post-and-core restorations is better than the survival of direct post-and-core restorations and post-free all-composite cores; and (2)the survival of these buildup restorations is influenced by the remaining dentin height after preparation.
  
  
  METHODS
  In a clinical trial, 18 operators made 319 core restorations in 249 patients. The restorations involved were: (1) cast post-and-core restorations; (2) direct post and composite core restorations; and (3) post-free all-composite cores. All restorations were made under single porcelain-fused-to-metal crowns. Treatments were allocated after dentin height assessment using balanced drawing. Failures were registered during a 5-year period.
  
  
  RESULTS
  Fifteen restorations failed during the follow-up period. Five failures occurred during the first month; they were considered to be independent from clinical aging and excluded from further survival assessments. The overall survival was 96%+/-2%. No difference was found between the survivals of the different types of restorations. The factor "remaining dentin height" appeared to have a significant effect on the survival of post-and-core restorations (98%+/-2% survival for "substantial dentin height" vs 93%+/-3% for "minimal dentin height").
  
  
  CONCLUSIONS
  The type of post and core was not relevant with respect to survival. The amount of remaining dentin height after preparation influenced the longevity of a post-and-core restoration.
authors.affiliation: Department of Oral Function and Prosthetic Dentistry, College of Dental Science, University Medical Centre Nijmegen, University of Nijmegen, Nijmegen 6500 HB, The Netherlands. n.creugers@dent.umcn.nl
authors.forename: Nico H J
authors.initials: NH
authors.lastname: Creugers
authors.forename: Arno G M
authors.initials: AG
authors.lastname: Mentink
authors.forename: Wietske A
authors.initials: WA
authors.lastname: Fokkinga
authors.forename: Cees M
authors.initials: CM
authors.lastname: Kreulen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003188:Composite Resins; D003442:Crowns; D003735:Dental Casting Technique; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003804:Dentin / Q000033:anatomy & histology; D005260:Female; D005500:Follow-Up Studies; D017408:Guidelines as Topic; D006801:Humans; D015993:Life Tables; D008297:Male; D016876:Metal Ceramic Alloys; D008875:Middle Aged; D011176:Post and Core Technique; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D019231:Tooth Preparation, Prosthodontic
chemical_list: D003188:Composite Resins; D016876:Metal Ceramic Alloys