title: A 3-year study of inlays milled from machinable ceramic blocks representing 2 different inlay systems.
abstract: OBJECTIVE
  The aim of this study was to evaluate the clinical performance of ceramic inlays made from machinable ceramic blocks.
  
  
  METHODS
  The 2 inlay systems involved computer-aided design and computer-aided machining (Cerec Cos 2.1) or copy-milling technique (Celay). The study comprised 15 Celay inlays and 15 Cerec inlays placed in 17 patients. The inlays were evaluated clinically at baseline (1 week) as well as 1 and 3 years later (modified California Dental Association quality evaluation system).
  
  
  RESULTS
  One Celay inlay fractured after 1 year of service, and 2 Cerec inlays were replaced, 1 after 6 months and 1 after 1 year, because of pulpal pain and persisting hypersensitivity. One Celay inlay lost retention after 2 years. At the 3-year evaluation, chipping and hairline cracks were seen in 2 Celay inlays. Progressive disintegration of the marginal luting cement was seen for both Celay and Cerec inlays. The remaining 25 inlays performed satisfactorily throughout the 3-year period.
  
  
  CONCLUSIONS
  Because of their relatively high failure rate, these inlays should be reserved for esthetic indications.
authors.affiliation: Department of Dental Pathology, Operative Dentistry and Endodontics, Royal Dental College, University of Aarhus, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Thordrup
authors.forename: F
authors.initials: F
authors.lastname: Isidor
authors.forename: P
authors.initials: P
authors.lastname: Hörsted-Bindslev
mesh_terms: D002484:Cementation; D002516:Ceramics; D016009:Chi-Square Distribution; D017076:Computer-Aided Design; D003775:Dental Polishing / Q000379:methods; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D007284:Inlays; D008137:Longitudinal Studies; D018709:Statistics, Nonparametric
chemical_list: C078572:Celay; D003776:Dental Porcelain; C074543:Cerec