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Antecedentes: Los agentes blanqueadores oxidantes tales como los peróxidos generan daños irreversibles en el esmalte dental y afectan químicamente el componente orgánico e inorgánico del esmalte. Se reportan en la literatura sustancias alternativas que pueden mejorar el color del esmalte, sin causarle daño. Objetivo: Identificar las sustancias blanqueadoras tipo remineralizante reportadas en la literatura y su efecto en el color del esmalte dental. Métodos: Se consultaron las bases de datos PubMed, ScienceDirect, Embase, Scielo, Lilacs y Scopus, las palabras clave empleadas para la búsqueda fueron dental enamel, tooth bleaching, bleaching, calcium phosphate, hidroxyapatite, apatite, biomimetic, biomimetics, conectadas por el operador booleano AND y OR de diferentes maneras. Los criterios de elegibilidad de los artículos que harían parte de la revisión fueron que no incluyeran peróxidos de hidrógeno y carbamida con adición fluoruros y fosfatos de calcio y adicionalmente que emplearan un método de medición de color. Resultados: El resultado de la búsqueda arrojó 7 artículos, las sustancias encontradas de tipo remineralizante fueron hidroxiapatita sintética, fosfatos de calcio y el hexametafosfato de sodio. Según los criterios de evaluación definidos solo 4 de ellos tuvieron un nivel de evidencia alto, uno nivel medio y dos bajos. Todos los estudios reportan con los tratamientos probados, la capacidad de generar cambios en el color del esmalte dental. Conclusión: Las sustancias blanqueadoras remineralizantes encontradas, tienen la capacidad de producir cambios en el color del esmalte dental, lo cual se evidencia con modificación en las diferentes escalas de medición empleadas.

Background: Oxidizing bleaching agents such as peroxides generate irreversible damage to dental enamel and chemically affect the organic and inorganic component of the enamel. Alternative substances that can improve the color of the enamel without damaging it are reported in the literature. Purpose: To identify the remineralizing bleaching substances reported in the literature and their effect on the color of the dental enamel. Methods: The databases PubMed, ScienceDirect, Embase, SciELO, Lilacs and Scopus were consulted, the keywords used for the search were dental enamel, tooth bleaching, bleaching, calcium phosphate, hydroxyapatite, apatite, biomimetic, biomimetics, connected by the Boolean operator AND and OR in different ways. The eligibility criteria of the articles that would be part of the review were not to include hydrogen peroxide and carbamide peroxides with addition of fluorides and calcium phosphates and additionally using a color measurement method. Results: The result of the search yielded 7 articles, the substances found of remineralizing type were synthetic hydroxyapatite, calcium phosphates and sodium hexametaphosphate. According to the evaluation criteria defined, only 4 of them had a high level of evidence, one medium level and two low. All studies report with proven treatments the ability to generate changes in tooth enamel color. Conclusions: The remineralizing whitening substances found have the ability to produce changes in the color of the dental enamel, which is evidenced with modification in the different measurement scales used.

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A new tetranuclear copper(II) complex which mimics the active site of catechol oxidase was synthesized and characterized by IR, CHN, electronic spectroscopic and (1)H NMR methods. The title complex [Cu(2)(mu-OH)(bpbpmp-NO(2))](2)[ClO(4)](2) was employed in the construction of a novel biomimetic sensor and used in the determination of chlorogenic acid by square wave voltammetry. The performance and optimization of the resulting biomimetic sensor were studied in detail. The best response of this sensor was obtained for 75:15:10% (w/w/w) ratio of the graphite powder:nujol:Cu(II) complex, 0.1 mol L(-1) phosphate buffer solution (pH 7.0), with frequency, pulse amplitude, and scan increment at 30 Hz, 100 mV, and 3.0 mV, respectively. The chlorogenic acid concentration was linear in the range of 5.0x10(-6) to 1.45x10(-4)mol L(-1) (r=0.9985) with a detection limit of 8.0x10(-7)mol L(-1). This biomimetic sensor demonstrated long-term stability (250 days; 640 determinations) and reproducibility, with a relative standard deviation of 10.0%. The recovery study of chlorogenic acid in coffee samples gave values from 93.2% to 106.1% and the concentrations determined showed good agreement when compared with those obtained using capillary electrophoresis at the 95% confidence level.

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The fabrication of supramolecular structures from the tetraruthenated porphyrin-containing phosphines, {TPyP[RuCl3(dppb)]4}, RuTPyP, is demonstrated with Langmuir and Langmuir-Blodgett films. The surface pressure-molecular area isotherms (pi-A) point to an edge-on arrangement for the RuTPyP molecules in the condensed state. Weak aggregation in the Langmuir films was indicated by non-zero surface potentials at large areas per molecule and a slight red shift in the ultraviolet-visible absorption spectrum in comparison to the spectrum in solution. Further aggregation occurs in the Z-type Langmuir-Blodgett films, which was confirmed with ultraviolet-visible spectroscopy of the deposited films. Fourier transform infrared and Raman spectroscopic data for powder and Langmuir-Blodgett films indicate that the RuTPyP molecules are chemically stable in Langmuir-Blodgett films regardless of the contact with water during film fabrication. The nanostructured nature of the Langmuir-Blodgett films was manifested in cyclic voltammetry due to the high sensitivity of the metallic centers in RuTPyP. Electrodes modified with Langmuir-Blodgett films exhibit an anodic peak at 100 mV and a cathodic peak at 7 mV, which is assigned to RuIII/RuII redox processes. Furthermore, Langmuir-Blodgett films from RuTPyP showed electrocatalytic activity for oxidation of benzyl alcohol, illustrated by a large shift of 100 mV in the anodic peak at 400 mV, while electropolymerized and cast films of the same compound displayed smaller and no activities, respectively.

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