title: Cleaning Methods for Zirconia Following Salivary Contamination.
abstract: OBJECTIVE
  To determine the best method of cleaning saliva-contaminated zirconia in preparation for resin bonding.
  
  
  METHODS
  Flat blocks of zirconia were particle abraded with aluminum oxide and divided into eight groups (n = 10). Groups 1 to 4 were first treated with one coat of an MDP primer (Z-prime Plus) and groups 5 to 8 were left untreated. A thin coat of fresh whole saliva was painted on all specimens (except the control, group 1) and left in contact for 3 minutes. The specimens were then cleaned by rinsing with water for 20 seconds (groups 2 and 5), or cleaned with 35% phosphoric acid for 20 seconds and rinsed (groups 3 and 6), or cleaned with a zirconia cleaning solution (Ivoclean) for 20 seconds and rinsed (groups 4 and 7), or abraded with aluminum oxide particles and rinsed (group 5). Following the cleaning procedure, groups 5 to 8 were treated with one coat of Z-prime Plus. A 2.5 mm diameter tube was filled with composite (Z100), affixed to the zirconia surface, and light-cured. Specimens were stored in water (37°C for 24 hours) followed by thermocycling (5°C to 55°C for 10,000 cycles). Shear bond strength testing was performed at a crosshead speed of 1 mm/min. Bond strength values were compared to the control using a Dunnett's test (alpha = 0.05). Contact angles of the zirconia specimens with and without Z-prime Plus were measured with water using a goniometer.
  
  
  RESULTS
  Groups 2, 5, and 8 were not significantly different from the control. Application of Z-prime made the zirconia surface more hydrophobic.
  
  
  CONCLUSIONS
  If salivary contamination occurs after MDP application, rinsing off the saliva with water will preserve bond strength. If salivary contamination occurs prior to MDP application, particle abrasion or cleaning with Ivoclean will preserve bond strength.
authors.affiliation: University of Alabama at Birmingham School of Dentistry, Restorative Sciences, Division of Prosthodontics, Birmingham, AL.
authors.forename: Pattarika
authors.initials: P
authors.lastname: Angkasith
authors.affiliation: University of Alabama at Birmingham School of Dentistry, Clinical and Community Sciences, Division of Biomaterials, Birmingham, AL.
authors.forename: John O
authors.initials: JO
authors.lastname: Burgess
authors.affiliation: Indiana University School of Dentistry, Biomedical and Applied Sciences, Division of Dental Biomaterials, Indianapolis, IN.
authors.forename: Marco C
authors.initials: MC
authors.lastname: Bottino
authors.affiliation: University of Alabama at Birmingham School of Dentistry, Clinical and Community Sciences, Division of Biomaterials, Birmingham, AL.
authors.forename: Nathaniel C
authors.initials: NC
authors.lastname: Lawson
mesh_terms: D001840:Dental Bonding; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D015040:Zirconium
chemical_list: D019279:Resin Cements; D015040:Zirconium; C028541:zirconium oxide
keywords: Ivoclean; MDP; Zirconia; phosphoric acid; saliva contamination