title: Susceptibility of enamel surfaces to demineralization after application of fluoridated carbamide peroxide gels.
abstract: The aim of the present study was to evaluate the effect of experimental, fluoridated carbamide peroxide gels on formation of erosively induced demineralization of enamel. Seventy-five bovine enamel specimens were polished for microhardness determination and evenly distributed among 5 groups (A-E). The specimens were treated with 10% carbamide peroxide gel (8 h) and subjected twice to remineralization for 2 h in artificial saliva and demineralisation for 90 s in 1% citric acid, pH 2.2. The cycles of treatment with carbamide peroxide and twofold re- and demineralization were repeated three times. The carbamide peroxide gels were different in pH and fluoride content. Gel A (pH 7.0) and gel B (pH 5.7) were fluoridated (0.5% F), gel C (pH 7.0) and gel D (pH 5.7) were not fluoridated. In control group E the samples were not treated with a gel, but stored in 100% humidity for 8 h instead. Knoop microhardness of the specimens was assessed directly after polishing, and after each carbamide peroxide treatment and demineralization. All specimens showed a loss of microhardness at the end of the experiment. After 3 days, the controls revealed a significantly lower hardness loss compared to the specimens treated with the carbamide peroxide gels. Surface softening was significantly lower for the specimens of group A compared to the remaining groups (B-D), which were not significantly different among each other. It is concluded that treatment with either fluoridated or unfluoridated carbamide peroxide gels, at either neutral and acidic pH, renders enamel more susceptible to demineralization. Use of a fluoridated neutral gel decreases the degree of surface softening compared to the other gels investigated.
authors.affiliation: Department of Operative Dentistry, Preventive Dentistry and Periodontology, Georg August University Göttingen, Göttingen, Germany. thomas.attin@med.uni-goettingen.de
authors.forename: T
authors.initials: T
authors.lastname: Attin
authors.forename: M
authors.initials: M
authors.lastname: Kocabiyik
authors.forename: W
authors.initials: W
authors.lastname: Buchalla
authors.forename: C
authors.initials: C
authors.lastname: Hannig
authors.forename: K
authors.initials: K
authors.lastname: Becker
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000077463:Carbamide Peroxide; D002327:Cariostatic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002417:Cattle; D019343:Citric Acid / Q000009:adverse effects; D003743:Dental Enamel / Q000187:drug effects*; D003747:Dental Enamel Solubility / Q000187:drug effects; D004338:Drug Combinations; D005459:Fluorides / Q000008:administration & dosage / Q000627:therapeutic use*; D005782:Gels; D006244:Hardness; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D016877:Oxidants / Q000627:therapeutic use*; D010545:Peroxides / Q000627:therapeutic use*; D012464:Saliva, Artificial / Q000627:therapeutic use; D013696:Temperature; D013997:Time Factors; D017001:Tooth Demineralization / Q000139:chemically induced*; D014077:Tooth Erosion / Q000139:chemically induced; D014089:Tooth Remineralization; D014508:Urea / Q000031:analogs & derivatives / Q000627:therapeutic use*
chemical_list: D002327:Cariostatic Agents; D004338:Drug Combinations; D005782:Gels; D016877:Oxidants; D010545:Peroxides; D012464:Saliva, Artificial; D019343:Citric Acid; D000077463:Carbamide Peroxide; D014508:Urea; D005459:Fluorides