title: Effect of selective enamel etching on clinical performance of CAD/CAM partial ceramic crowns luted with a self-adhesive resin cement.
abstract: OBJECTIVE
  This study was conducted to evaluate a self-adhesive resin luting cement [RelyX Unicem 3MESPE-RXU] for luting partial ceramic crowns (PCCs) with and without selective enamel etching in a prospective, randomized clinical trial.
  
  
  METHODS
  Thirty-four patients had received the intended treatment. Two PCCs (Vita Mark II; Cerec 3D; Sirona) had been placed in a split-mouth design: one with RXU without enamel etching (RXU), the other with RXU with selective enamel etching (RXU + E). Restorations were evaluated at baseline (BL) and after 12, 24, and 36 months (USPHS criteria). For statistical analysis, the Chi-square test was applied (α = 0.05). Clinical survival of all restorations (n = 68) after 3 years was determined using Kaplan-Meier analysis.
  
  
  RESULTS
  Twenty three patients (12 male/11 female) were available for clinical evaluation after 3 years. 19 RXU-PCCs were placed in molars, four in premolars, 18 RXU + E-PCCs in molars, five in premolars. Concerning clinical changes, no significant differences were found between luting strategies RXU/RXU + E at all recalls. Statistically significant changes over time were observed for marginal adaptation and marginal discoloration between BL and 36 m for RXU and RXU + E. For RXU + E, postoperative hypersensitivities decreased significantly from BL (n = 6) to 36 m (n = 0). Of the 68 restorations originally included, eight RXU and four RXU + E restorations failed. At 3 years, Kaplan-Meier survival of RXU was 72.9 %, that of RXU + E 87.6 %. Survival rates were not statistically significant different.
  
  
  CONCLUSIONS
  Although clinical survival of RXU + E is slightly better at 3 years, restorations of both groups perform similar with respect to clinical changes over time as evaluated by modified USPHS criteria.
  
  
  CONCLUSIONS
  The self-adhesive resin cement RXU can be used in conjunction with selective enamel etching, because survival rates of PCCs in the RXU + E group were not lower but, as a trend, even better than without enamel etching.
authors.affiliation: Department of Operative Dentistry and Periodontology, Dental School, University of Regensburg, Franz Josef Strauss Alle 11, 93053, Regensburg, Germany, marianne.federlin@klinik.uni-regensburg.de.
authors.forename: Marianne
authors.initials: M
authors.lastname: Federlin
authors.forename: Karl-Anton
authors.initials: KA
authors.lastname: Hiller
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schmalz
mesh_terms: D000134:Acid Etching, Dental; D002516:Ceramics; D003188:Composite Resins; D003442:Crowns; D003738:Dental Cements; D003743:Dental Enamel; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies
chemical_list: D003188:Composite Resins; D003738:Dental Cements