title: Influence of whitening on the degree of conversion of dental adhesives on dentin.
abstract: The aim of this study was to analyze the extent of polymerization of different adhesive systems on whitened dentin. One adhesive of each class was investigated: Adper Scotchbond Multi Purpose (3M ESPE); One-Step (Bisco); Clearfil Protect Bond (Kuraray); and Xeno III (Dentsply DeTrey). Dentin disks were treated with Opalescence Xtra Boost (Ultradent) for 30 min and bonded immediately after 24 h or after 14 d of storage in 100% humidity at 37 degrees C. Unbleached dentin disks were prepared as controls. The extent of polymerization of bonded interfaces was obtained with differential scanning calorimetry (DSC) at 20, 40 and 60 s, and the data were statistically analyzed. The extent of polymerization obtained from DSC exotherms of adhesives applied immediately after whitening was significantly lower compared with controls. An increased extent of polymerization after storage was confirmed for all adhesives, and no difference with controls was found after 14 d. A prolonged irradiation time increased the curing rate for all the tested adhesives. This study supports the hypothesis that polymerization of the adhesive is reduced after dentin whitening and that delayed adhesive application reverses the polymerization inhibition. Prolonged polymerization intervals may counteract the inhibition of polymerization caused by the whitening procedure. Nevertheless, further in vivo studies should validate this issue.
authors.affiliation: UCO of Dental Sciences, Department of Biomedicine, University of Trieste, Trieste, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Cadenaro
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Breschi
authors.forename: Francesca
authors.initials: F
authors.lastname: Antoniolli
authors.forename: Annalisa
authors.initials: A
authors.lastname: Mazzoni
authors.forename: Roberto
authors.initials: R
authors.lastname: Di Lenarda
mesh_terms: D000293:Adolescent; D000328:Adult; D002152:Calorimetry, Differential Scanning; D001840:Dental Bonding; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004338:Drug Combinations; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D016877:Oxidants / Q000627:therapeutic use*; D010545:Peroxides / Q000627:therapeutic use; D011108:Polymers / Q000737:chemistry; D011145:Polyvinyls / Q000627:therapeutic use; D019279:Resin Cements / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D014508:Urea / Q000031:analogs & derivatives / Q000627:therapeutic use
chemical_list: C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; C503075:Clearfil Protect Bond; D017220:Dentin-Bonding Agents; D004338:Drug Combinations; D008689:Methacrylates; D016877:Oxidants; D010545:Peroxides; D011108:Polymers; D011145:Polyvinyls; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C487957:Xeno III; C093177:tooth-bleaching agent, Opalescence; D014508:Urea