title: Effect of fluoridated carbamide peroxide gels on enamel microtensile bond strength.
abstract: The aim of this study was to examine the resin bond strength on enamel treated with different fluoridated bleaching agents. Forty-eight bovine incisors were divided into four groups to receive bleaching treatments, over a 14-d period, as follows: no treatment; 10% carbamide peroxide (CP) bleaching; 10% CP containing 0.11% fluoride; and 10% CP containing 0.37% fluoride. Immediately, and 7 and 14 d after bleaching, the enamel surfaces were respectively bonded with composite and sectioned to create resin-enamel beams. These beams were subjected to the microtensile bond strength (microTBS) test, then assessed for failure mode under scanning electron microscopy. The results showed that the 0.37% fluoridated group demonstrated a microTBS equivalent to that of the unbleached group at all stages. Non-fluoridated and 0.11% fluoridated groups showed a weaker microTBS after bleaching but regained the bond strength after 14 or 7 d of storage, respectively. In the non-fluoridated group, adhesive failure was the predominant fracture pattern that comprised the enamel prism demineralization change and widely dispersed voids on the resin-enamel interfaces. No evident enamel erosion and fewer microporosities were found in the 0.37% fluoridated group. Accordingly, treatment with 0.37% fluoridated CP maintained the microTBS as effectively as the unbleached enamel. Additional fluoride in the bleaching agents may facilitate subsequent restorative treatment by inhibiting enamel demineralization.
authors.affiliation: Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan. sfchuang@mail.ncku.edu.tw
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Chuang
authors.forename: Hui-Ping
authors.initials: HP
authors.lastname: Chen
authors.forename: Chih-Han
authors.initials: CH
authors.lastname: Chang
authors.forename: Jia-Kuang
authors.initials: JK
authors.lastname: Liu
mesh_terms: D000268:Adhesiveness; D000818:Animals; D000077463:Carbamide Peroxide; D002327:Cariostatic Agents / Q000737:chemistry*; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D004338:Drug Combinations; D005459:Fluorides / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D016877:Oxidants / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry*; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D002327:Cariostatic Agents; D003188:Composite Resins; D004338:Drug Combinations; C444701:Filtek Z250; D016877:Oxidants; D010545:Peroxides; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; D000077463:Carbamide Peroxide; D014508:Urea; D012969:Sodium Fluoride; D005459:Fluorides