China
Africa
Explore chapters and articles related to this topic
Chemicals from Non-hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Finally, one of the most important groups of hydrogen compounds is the acids. Common inorganic acids include hydrochloric acid (HCl), sulfuric acid (H2SO4), nitric acid (HNO3), phosphoric acid (H3PO4), hydrofluoric acid (HF), and boric acid (H3BO3). Although not a typical hydrogen acid, hydrogen peroxide (H2O2) is a weak acid, but is a strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials. In keeping with the strong oxidizing properties, hydrogen peroxide is a powerful bleaching agent that is mostly used for bleaching paper, but has also found use as a disinfectant and as an oxidizer. Hydrogen peroxide in the form of carbamide peroxide (a solid composed of equal amounts of hydrogen peroxide and urea (H2NCONH2)), which is a white crystalline solid that dissolves in water to give free hydrogen peroxide is widely used for tooth whitening (bleaching), both in professionally administered and self-administered products.
Household and Personal Care Products: Cleaning up and Looking Good
Published in Richard J. Sundberg, The Chemical Century, 2017
Toothpastes contain several ingredients including abrasives, surfactants, humectants, thickeners, and specific varieties also include fluoride, tartar control agents, whiteners, antibacterials, flavors, and colors. The abrasives assist removal of adhering material, particularly a thin proteinaceous film called the pellicle. Surfactants disperse plaque and other material loosened by brushing. The humectants keep the paste fluid and contribute to taste. Tartar and calculus are hardened material built up from deposits of calcium salts. Inhibition of tartar build-up is one of the goals of toothpaste and tooth-brushing. The most common agents for this purpose are pyrophosphate salts. They seem to function by inhibiting the hardening of the initial amorphous deposits and this effect can be modeled in vitro. A combination of NaF and pyrophosphate can attain about 25% inhibition of tartar build up and a combination of pyrophosphate with (methyl vinyl ether)–maleic acid copolymer (PVM–MA) achieves a 50% reduction.11 Whitening agents are usually either hydrogen peroxide or the hydrogen peroxide precursor carbamide peroxide.12 They are applied in such a fashion as to minimize contact with the gum. Table 6.8 lists examples of the types of major ingredients.
Mass Transfer in Binary Systems without Bulk Flow: Steady-State Examples
Published in İsmail Tosun, Fundamental Mass Transfer Concepts in Engineering Applications, 2019
4.12 Tooth color is an important aspect of aesthetics. In that respect, dental whitening is a frequently used method to obtain sparkling white teeth. Dental whiteners are bleaching agents, such as hydrogen peroxide or carbamide peroxide, that diffuse into the tooth and react with stain molecules.
Regulatory compliance of online vendor selling dental whitening products in New Zealand
Published in Journal of the Royal Society of New Zealand, 2023
Christina Oude-Alink, Haizal Mohd Hussaini, Benedict Seo, Fiona Firth
Tooth whitening involves bleaching tooth surfaces using either hydrogen or carbamide peroxide (Carey 2014). At-home tooth whitening using 10% carbamide peroxide with custom trays is the most common bleaching procedure prescribed by dentists (Demarco et al. 2009). To meet the demand of patients wanting a fast, cheap and straightforward way to get a whiter smile, a large variety of over-the-counter (OTC) whitening products have become available on the market, predominantly via the internet (Castro et al. 2015). Most companies selling unsupervised OTC tooth whitening kits online market peroxide-containing gels along with universal mouth trays (Demarco et al. 2009).