title: Bond Strength of Resin Composite to Dentin with Different Adhesive Systems: Influence of Relative Humidity and Application Time.
abstract: OBJECTIVE
  To investigate the influence of relative humidity and application time on bond strength to dentin of different classes of adhesive systems.
  
  
  METHODS
  A total of 360 extracted human molars were ground to mid-coronal dentin. The dentin specimens were treated with one of six adhesive systems (Syntac Classic, OptiBond FL, Clearfil SE Bond, AdheSE, Xeno Select, or Scotchbond Universal), and resin composite (Filtek Z250) was applied to the treated dentin surface under four experimental conditions (45% relative humidity/application time according to manufacturers' instructions; 45% relative humidity/reduced application time; 85% relative humidity/application time according to manufacturers' instructions; 85% relative humidity/reduced application time). After storage (37°C, 100% humidity, 24 h), shear bond strength (SBS) was measured and data analyzed with nonparametric ANOVA followed by Kruskal-Wallis tests and Mann-Whitney U-tests with Bonferroni-Holm correction for multiple testing (level of significance: α = 0.05).
  
  
  RESULTS
  Increased relative humidity and reduced application time had no effect on SBS for Clearfil SE Bond and Scotchbond Universal (p = 1.00). For Syntac Classic, OptiBond FL, AdheSE, and Xeno Select there was no effect on SBS of reduced application time of the adhesive system (p ≥ 0.403). However, increased relative humidity significantly reduced SBS for Syntac Classic, OptiBond FL, and Xeno Select irrespective of application time (p ≤ 0.003), whereas for AdheSE, increased relative humidity significantly reduced SBS at recommended application time only (p = 0.002).
  
  
  CONCLUSIONS
  Generally, increased relative humidity had a detrimental effect on SBS to dentin, but reduced application time had no effect.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Amsler
authors.forename: Anne
authors.initials: A
authors.lastname: Peutzfeldt
authors.forename: Adrian
authors.initials: A
authors.lastname: Lussi
authors.forename: Simon
authors.initials: S
authors.lastname: Flury
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; C489662:AdheSE cement; C438313:Clearfil SE Bond; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; C469607:OptiBond FL; D019279:Resin Cements; C078484:Syntac dentine adhesive; C487957:Xeno III; C041330:Scotchbond