title: Retentive strength of two-piece CAD/CAM zirconia implant abutments.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the retention of two-piece computer-aided design (CAD)/computer aided manufacturing (CAM) zirconia abutments after artificial aging under simulated oral conditions using three different types of resin-based luting agents.
  
  
  METHODS
  Twenty-one CAD/CAM-generated zirconia copings (CERCON Compartis, Degudent, Hanau, Germany) were bonded to a prefabricated secondary titanium implant insert (XiVE Ti-Base, Dentsply Friadent, Mannheim, Germany), using three different types of resin-based luting agents: group A: Panavia 21 (Kuraray Co, Kurashiki, Japan); group B: Multilink Implant (Ivoclar Vivadent, Schaan, Liechtenstein); and group C: SmartCem2 (Dentsply DeTrey, Konstanz, Germany). The bonding surfaces of the titanium inserts and the zirconia ceramic copings were air-abraded and cleaned in alcohol. All specimens were stored in distilled water for 60 days and subsequently thermal-cycled 15,000 times (5-55 °C). The dislodging force of the copings along the long axis of the implant/abutment complex was recorded using a universal testing machine with 2 mm/min crosshead speed. Data were analyzed descriptively and by performing the Kruskal-Wallis test.
  
  
  RESULTS
  The mean retention values were 924.93 ± 363.31 N for Panavia 21, 878.05 ± 208.33 N for Multilink Implant, and 650.77 ± 174.92 N for SmartCem2. The Kruskal-Wallis test indicated no significant difference between the retention values of the tested luting agents (p = 0.1314). The failure modes of all tested two-piece abutments were completely adhesive, leaving the detached zirconia coping and titanium insert undamaged.
  
  
  CONCLUSIONS
  The use of resin-based luting agents in combination with air abrasion of titanium inserts and zirconia copings led to a stable retention of two-piece CAD/CAM abutments. The bonding stability of the investigated luting agents exceeded the general limits of fracture resistance of two-piece zirconia abutments. A notable difference between the mean retention values of the tested bond materials was shown. However, the statistical analysis revealed that this difference was not significant.
authors.affiliation: Ludwigshafen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Gehrke
authors.forename: Jochen
authors.initials: J
authors.lastname: Alius
authors.forename: Carsten
authors.initials: C
authors.lastname: Fischer
authors.forename: Kurt J
authors.initials: KJ
authors.lastname: Erdelt
authors.forename: Florian
authors.initials: F
authors.lastname: Beuer
mesh_terms: D017076:Computer-Aided Design; D000044:Dental Abutments; D001840:Dental Bonding / Q000379:methods*; D045662:Dental Etching / Q000379:methods; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry*; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D010710:Phosphates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D015921:Dental Implants; D003764:Dental Materials; C093719:Panavia TPN-S; D010710:Phosphates; D019279:Resin Cements; C502351:multilink adhesive system; D014867:Water; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide
keywords: bonding; computer assisted; titanium; two-piece CAD/CAM abutments; zirconia