title: Microleakage of porcelain veneer restorations bonded to enamel and dentin with a new self-adhesive resin-based dental cement.
abstract: Cementation technique of bonded ceramic restorations is a time-consuming and technique-sensitive procedure critical to long-term success.
  
  
  OBJECTIVE
  Evaluate the performance of a self-adhesive, modified-resin dental cement (Rely-X UniCem, 3M-ESPE) for the cementation of ceramic veneer restorations without previous conditioning of the tooth surface, and in combination with a one-bottle adhesive and a self-etching adhesive.
  
  
  METHODS
  Thirty-six premolars received a veneer preparation that extended into dentin. Leucite-reinforced pressed glass ceramic (Empress 1) veneers were cemented following manufacturers' instructions, according to the following treatment groups (n=9): (1) Variolink-Excite Ivoclar-Vivadent (V+E control), (2) Unicem+Single Bond 3M-ESPE (U+SB), (3) Unicem+Adper Prompt L-Pop 3M-ESPE (U+AP), (4) Unicem 3M-ESPE (U). After 24h storage at 37 degrees C, teeth were thermocycled (2000 cycles) at 5 and 55 degrees C, immersed in ammoniacal silver nitrate for 24h, placed in a developer solution overnight and sectioned using a slow-speed saw. Three 1mm longitudinal sections were obtained from each tooth and evaluated for leakage with a microscope (1x to 4x). Imaging software was used to measure stain penetration along the dentin and enamel surfaces.
  
  
  RESULTS
  ANOVA with SNK (alpha=0.05) revealed that on dentin, U had significantly less leakage than U+SB and U+AP, but no different than V+E; on enamel U had leakage values that were significantly greater than the groups with adhesives.
  
  
  CONCLUSIONS
  The self-adhesive cement U gave low leakage on dentin that was comparable to the cement that employed an adhesive for sealing dentin, whereas this cement benefits from use of an adhesive when cementing to enamel.
authors.affiliation: School of Dentistry, Department of Restorative Dentistry, University of Washington, Seattle, WA 98195-7456, USA. gibarra@u.washington.edu
authors.forename: Gabriela
authors.initials: G
authors.lastname: Ibarra
authors.forename: Glen H
authors.initials: GH
authors.lastname: Johnson
authors.forename: Werner
authors.initials: W
authors.lastname: Geurtsen
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Vargas
mesh_terms: D000134:Acid Etching, Dental; D000538:Aluminum Silicates / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002484:Cementation; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003763:Dental Leakage / Q000145:classification*; D003776:Dental Porcelain / Q000737:chemistry*; D003801:Dental Veneers; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D016622:Silver Staining; D013696:Temperature; D013997:Time Factors
chemical_list: D000538:Aluminum Silicates; D017220:Dentin-Bonding Agents; C420130:Excite cement; C075815:IPS-Empress ceramic; D008689:Methacrylates; C408584:Prompt L-Pop; C483701:Rely X Unicem; D019279:Resin Cements; C115612:single bond; D003776:Dental Porcelain; C078519:leucite; C103502:Variolink; D017438:Bisphenol A-Glycidyl Methacrylate