title: The influence of dentin and/or metal surface treatment on the retention of cemented crowns in teeth with an increased taper.
abstract: OBJECTIVE
  To evaluate the effect of dentin and/or metal surface treatments on retention of cast crowns cemented to preparations with compromised retention.
  
  
  METHODS
  Cast crowns (n=105) were fabricated on extracted molars prepared to 40 degrees convergence and standard height. 60 teeth were randomly divided into: (A) cemented with zinc phosphate cement; (B-D) cemented with resin cement (Compolute, 3M) with either no surface treatment (B), dentin etched and bonded (EBS multi, 3M) (C), or dentin etched and bonded, and metal tribochemically treated (Co-Jet, 3M) (D); 45 teeth were randomly divided and crowns cemented with another resin cement (Rely-X Arc, 3M) with either no surface treatment (E), dentin etched and bonded (Single Bond, 3M) (F), or dentin etched and bonded and metal tribochemically treated (G). Teeth were stored in 100% humidity for 3 months and thermocycled 5000 cycles. Crowns were dislodged from the preparations and retention (MPa) was calculated.
  
  
  RESULTS
  Group D showed significantly higher retention (3.52+/-1.3 MPa) compared to Group C (2.26+/-0.9 MPa), Group B (0.85+/-0.4 MPa), and Group A (1.22+/-0.4 MPa). Group G exhibited significantly higher retention (5.4+/-1.4 MPa) compared to F (2.6+/-1.2 MPa) and E (2.0+/-0.6 MPa). Higher retention corresponded with more cohesive cement type of failure.
  
  
  CONCLUSIONS
  Cast crowns with compromised retention cemented by resin cement should undergo combined tribochemical metal treatment and dentin bonding. The crucial link is the interaction of different brands of resin cements with the metal tribochemically treated.
authors.affiliation: Department of Oral Rehabilitation, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. pilo99@netvision.net.il
authors.forename: Raphael
authors.initials: R
authors.lastname: Pilo
authors.forename: Israel
authors.initials: I
authors.lastname: Lewinstein
authors.forename: Tal
authors.initials: T
authors.lastname: Ratzon
authors.forename: Harold S
authors.initials: HS
authors.lastname: Cardash
authors.forename: Tamar
authors.initials: T
authors.lastname: Brosh
mesh_terms: D000134:Acid Etching, Dental; D000537:Aluminum Oxide / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002484:Cementation; D003442:Crowns; D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D045662:Dental Etching; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D003804:Dentin / Q000033:anatomy & histology*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012824:Silicic Acid / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: C418025:Compolute; D003722:Dental Alloys; D017220:Dentin-Bonding Agents; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; D012821:Silanes; C115612:single bond; D012824:Silicic Acid; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D015036:Zinc Phosphate Cement; D000537:Aluminum Oxide