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Tooth whitening or tooth bleaching is the process of lightening the colour of human teeth. [1] Whitening is often desirable when teeth become yellowed over time for a number of reasons, and can be achieved by changing the intrinsic or extrinsic colour of the tooth enamel. [2]
Teeth whitening strips are easy-to-use, peel-and-stick strips that you wear on your teeth for 15 to 30 minutes each day. "Most kits come with a 30-day supply and are relatively easy to use," says ...
The molecules of such solvents readily donate protons (H +) to solutes, often via hydrogen bonding. Water is the most common protic solvent. Conversely, polar aprotic solvents cannot donate protons but still have the ability to dissolve many salts. [1] [2] Methods for purification of common solvents are available [3]
Adhesive dentistry is a branch of dentistry which deals with adhesion or bonding to the natural substance of teeth, enamel and dentin.It studies the nature and strength of adhesion to dental hard tissues, properties of adhesive materials, causes and mechanisms of failure of the bonds, clinical techniques for bonding and newer applications for bonding such as bonding to the soft tissue. [1]
The general notation for hydrogen bonding is Dn−H···Ac, where the solid line represents a polar covalent bond, and the dotted or dashed line indicates the hydrogen bond. [6] The most frequent donor and acceptor atoms are nitrogen (N), oxygen (O), and fluorine (F), due to their high electronegativity and ability to engage in stronger ...
Teeth bleaching agents release reactive oxygen species which can degrade enamel. [27] To prevent this, nano-hydroxyapatite can be added to the bleaching solution to reduce the impact of the bleaching agent by blocking pores within the enamel. [27] This reduces sensitivity after the bleaching process. [28]
Exchange rates are a function of two parameters: solvent accessibility and hydrogen bonding. Thus an amide which is part of an intramolecular hydrogen bond will exchange slowly if at all, while an amide on the surface of protein hydrogen bonded to water will exchange rapidly. Amides buried from the solvent but not hydrogen bonded may also have ...
Like water, hydrogen bonding results in a high melting and boiling point compared to the other pnictogen hydrides, although 26% is lost on melting, another 7% as the liquid is heated to boiling, and the remaining 67% upon boiling. Other effects of hydrogen bonding are a high dielectric constant as well as low values of density, viscosity, and ...