Effect of fluoridated carbamide peroxide gels on enamel microtensile bond strength.
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.
Chuang
Shu-Fen
SF
Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan. sfchuang@mail.ncku.edu.tw
Chen
Hui-Ping
HP
Chang
Chih-Han
CH
Liu
Jia-Kuang
JK
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
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