title: Self-adhesive Luting of Partial Ceramic Crowns: Selective Enamel Etching Leads to Higher Survival after 6.5 Years In Vivo.
abstract: OBJECTIVE
  To investigate the influence of selective enamel etching on long-term clinical performance of partial ceramic crowns (PCCs) luted with a self-adhesive luting material (RXU: RelyX Unicem).
  
  
  METHODS
  At baseline, 34 patients received the intended treatment: two PCCs (Vita Mark II; Cerec 3D) for the restoration of extended lesions with multiple-cusp coverage were placed in a split-mouth design with a self-adhesive luting material, one without (RXU) and one with selective enamel etching (RXU+E). Patients were evaluated clinically (modified USPHS criteria) at baseline and up to 6.5 years (70 to 88 months). The chi-square test was used for statistical analyses (α=0.05). Clinical survival of all restorations (n=68) after 6.5 years was evaluated by Kaplan-Meier analysis.
  
  
  RESULTS
  After 6.5 years, 18 patients (9 male, 9 female; median age 41, range 25 to 59 years) with 36 RXU and RXU+E restorations were available for clinical assessment (patient recall rate: 53%), with 13 RXU and 14 RXU+E PCCs placed in molars and 5 RXU and 4 RXU+E PCCs in premolars. Clinically, no statistically significant differences between the luting procedures were detected. Both RXU and RXU+E revealed significant changes over time with respect to marginal adaptation (significant deterioration) and marginal discoloration (significant increase). RXU revealed no cases of postoperative hypersensitivity and RXU+E only did so at baseline (n=5). Kaplan-Meier analysis showed a cumulative survival for RXU of 60% and for RXU+E of 82%, indicating a significantly higher survival rate for RXU+E.
  
  
  CONCLUSIONS
  Clinically, RXU and RXU+E perform similarly. In PCC restorations with multiple-cusp coverage, lack of retention due to adhesive preparation, and little dentin available for adhesion caused by extensive core buildups or cavity linings, selective enamel etching is recommended.
authors.forename: Katharina
authors.initials: K
authors.lastname: Baader
authors.forename: Karl-Anton
authors.initials: KA
authors.lastname: Hiller
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Buchalla
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schmalz
authors.forename: Marianne
authors.initials: M
authors.lastname: Federlin
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000328:Adult; D003116:Color; D003442:Crowns; D001840:Dental Bonding / Q000379:methods*; D003743:Dental Enamel / Q000648:ultrastructure*; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D003807:Dentin Sensitivity / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D055115:Light-Curing of Dental Adhesives / Q000379:methods; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019279:Resin Cements / Q000737:chemistry*; D013499:Surface Properties; D016019:Survival Analysis; D019231:Tooth Preparation, Prosthodontic / Q000379:methods
chemical_list: C483701:Rely X Unicem; D019279:Resin Cements; C082340:Vita Mark II; D003776:Dental Porcelain; D006858:Hydrofluoric Acid