title: Composite vs ceramic computer-aided design/computer-assisted manufacturing crowns in endodontically treated teeth: analysis of marginal adaptation.
abstract: OBJECTIVE
  To compare the marginal adaptation between ceramic and composite CEREC crowns in endodontically treated teeth restored with endocrowns or with a short or a long post.
  
  
  METHODS
  Forty-eight intact maxillary incisors were used. After endodontic treatment, the crowns were sectioned 2 mm coronally to the cemento-enamel junction, which provided a ferrule of 2 mm. The prepared teeth were divided randomly into six groups (n=8). Group 1 was restored with a large fiberglass post, composite core, and ceramic full-coverage computer-aided design/computer-assisted manufacturing (CAD-CAM) crown. Group 2 was restored with a short fiberglass post, composite core, and ceramic full-coverage CAD-CAM crown. Group 3 was restored with a large fiberglass post, composite core, and composite full-coverage CAD-CAM crown (LPCpr). Group 4 was restored with a short fiberglass post, composite core, and composite full-coverage CAD-CAM crown (SPCpr). Groups 5 and 6 were restored with ceramic and composite CEREC machined endocrowns, respectively (EndoCer and EndoCpr). The restored teeth were loaded thermomechanically in a computer-controlled chewing machine. Impressions of each restoration were made in a polyvinylsiloxane material before and after loading. Gold-coated epoxy replicas were prepared for scanning electron microscopy examination at 200× magnification.
  
  
  RESULTS
  Loading had a statistically significant effect (p<0.05) on the percentage of "continuous margin" in all groups. The LPCpr, SPCpr, and EndoCpr groups showed the highest percentage of continuous margin initially and after loading. The effect of the different post lengths on marginal adaptation was not significant (p>0.05).
  
  
  CONCLUSIONS
  CAD-CAM crowns fabricated from millable composite resin blocks (Paradigm MZ100) offer a superior option to all-ceramic crowns (IPS Empress CAD).
authors.forename: A
authors.initials: A
authors.lastname: Ramírez-Sebastià
authors.forename: T
authors.initials: T
authors.lastname: Bortolotto
authors.forename: M
authors.initials: M
authors.lastname: Roig
authors.forename: I
authors.initials: I
authors.lastname: Krejci
mesh_terms: D003188:Composite Resins / Q000627:therapeutic use*; D017076:Computer-Aided Design; D003442:Crowns; D003776:Dental Porcelain / Q000627:therapeutic use*; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor; D012390:Root Canal Therapy / Q000379:methods
chemical_list: D003188:Composite Resins; D003776:Dental Porcelain