title: Influence of treatment modalities of prepared teeth on retention of cast metal copings bonded with self-adhesive resin cements.
abstract: OBJECTIVE
  To evaluate the influence of different conditioning methods of prepared teeth on the retention of cast metal copings bonded with two self-adhesive resin cements.
  
  
  METHODS
  Mandibular first molars (n = 80) were prepared to receive metal copings. Sixteen molars were stored in water without interim copings as a control group (CG), while 64 molars were covered with interim copings. Eighty cast copings were laboratory fabricated from Ni-Cr alloy. Interim copings were removed, and 64 molars were cleaned and divided into four groups (n = 16) according to pretreatment methods of prepared molars: no pretreatment (T-NT) and conditioning with self-etching adhesive (T-SE), polyacrylic acid (T-PA), or ethylenediaminetetraacetic acid (EDTA) (T-ED). Each group was further subdivided into two subgroups (n = 8) according to luting cements. RelyX Unicem and seT self-adhesive resin cements were used for cementation of copings. Specimens were stored in water at 37°C for 6 months and then cyclically loaded and thermal cycled. Retentive stress in N was recorded for each specimen. Statistical analyses were conducted with two- and one-way ANOVA and Tukey HSD test.
  
  
  RESULTS
  Retentive stress ranged from 526.7 to 692.9 N for RelyX Unicem and 339.8 to 492.3 N for seT. There were no statistically significant differences between the mean retentive stress of the CG, T-SE, and T-PA groups (P > .05). The mean retentive stress of group CG was significantly higher than mean retentive stress of groups T-NT and T-ED (P < .05). The mean retentive stress of the control and test groups bonded with RelyX Unicem was significantly higher than the mean retentive stress of the same groups bonded with seT.
  
  
  CONCLUSIONS
  Conditioning of prepared teeth using polyacrylic acid or self-etching adhesive significantly increased the retentive stress of cast metal copings.
authors.affiliation: Department of Conservative Dentistry and Fixed Prosthodontics, Faculty of Dentistry, Mansoura University, Mansora, Egypt. aattia@mans.edu.eg
authors.forename: Ahmed
authors.initials: A
authors.lastname: Attia
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000180:Acrylic Resins / Q000737:chemistry; D002484:Cementation / Q000379:methods; D002858:Chromium Alloys / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003442:Crowns; D000044:Dental Abutments; D001840:Dental Bonding / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry; D017268:Dental Prosthesis Retention; D003794:Dental Restoration, Temporary / Q000379:methods; D004492:Edetic Acid / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008963:Molar / Q000473:pathology; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D002858:Chromium Alloys; D003188:Composite Resins; D003764:Dental Materials; C498353:G-Bond; D008689:Methacrylates; D011140:Polyurethanes; C483701:Rely X Unicem; D019279:Resin Cements; D014867:Water; C029824:urethane dimethacrylate luting resin; C006903:carbopol 940; D004492:Edetic Acid