title: Influence of Different Types and Concentrations of Chemical Catalysts on Dental Bleaching Efficiency.
abstract: The objective of this study was to evaluate the effects of different types and concentrations of chemical catalysts on the efficiency of 35% hydrogen peroxide gel on dental bleaching. Enamel-dentin disks were obtained from bovine incisors and the initial color was assessed. The groups were divided according to the type and concentration of catalyst added to an experimental gel: ferrous sulphate (FS) (0.001, 0.002 and 0.003%); ferrous gluconate (Fg) (0.01, 0.02 and 0.03%); ferric chloride (FC) (0.01, 0.02 and 0.03%); manganese gluconate (MG) (0.01, 0.02 and 0.03%); and manganese chloride (MC) (0.01, 0.02 and 0.03%). The positive control (PC) group received the bleaching gel without any catalyst, while in the negative control (NC) the specimens remained in artificial saliva. Three applications of the bleaching gels were performed for 10 minutes each, repeated after 7 days. Color assessments were performed 7 days after the first session and 7 days after the second. The specimens were stored in artificial saliva and assessed again after 1 year. The data were analyzed by parametric analysis of variance and Tukey's test. Some of the chemical catalysts tested were effective in reducing the yellowish color of the samples in relation to the positive control group after 1 and 2 applications and diminished the color relapse over time. After 1 year, the FS was the most effective catalyst tested. We concluded that some chemical catalysts increased the efficiency of dental bleaching.
authors.affiliation: Associate Professor, Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University, Sao Paulo, Brazil, Phone: 55 12 3947-9376, e-mail: carlosrgt@gmail.com.
authors.forename: Carlos
authors.initials: C
authors.lastname: Rocha Gomes Torres
authors.affiliation: Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University, Sao Paulo, Brazil.
authors.forename: Carolina Anne
authors.initials: CA
authors.lastname: Guimarães
authors.affiliation: Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University, Sao Paulo, Brazil.
authors.forename: Zulene Eveline Abreu
authors.initials: ZE
authors.lastname: Ribeiro
authors.affiliation: Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University, Sao Paulo, Brazil.
authors.forename: Alessandra Bühler
authors.initials: AB
authors.lastname: Borges
mesh_terms: D000818:Animals; D002417:Cattle; D003743:Dental Enamel; D003804:Dentin; D006861:Hydrogen Peroxide; D012464:Saliva, Artificial; D013997:Time Factors; D014073:Tooth Bleaching; D058205:Tooth Bleaching Agents
chemical_list: D012464:Saliva, Artificial; D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide
keywords: Catalyst; Color; Dental bleaching; Esthetic; Hydrogen peroxide