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  2. Nitrite test - Wikipedia

    en.wikipedia.org/wiki/Nitrite_test

    A nitrite test is a standard component of a urinary test strip. A positive test for nitrites in the urine is called nitrituria. This test is commonly used in diagnosing urinary tract infections (UTIs). A positive nitrite test indicates that the cause of the UTI is a Gram-negative organism, most commonly Escherichia coli. The reason for nitrites ...

  3. Azo coupling - Wikipedia

    en.wikipedia.org/wiki/Azo_coupling

    In organic chemistry, an azo coupling is an reaction between a diazonium compound (R−N≡N +) and another aromatic compound that produces an azo compound (R−N=N−R’).In this electrophilic aromatic substitution reaction, the aryldiazonium cation is the electrophile, and the activated carbon (usually from an arene, which is called coupling agent), serves as a nucleophile.

  4. Tooth polishing - Wikipedia

    en.wikipedia.org/wiki/Tooth_polishing

    The purpose of polishing is to remove extrinsic stains, remove dental plaque accumulation, increase aesthetics and to reduce corrosion of metallic restorations. [ 1 ] [ 2 ] Tooth polishing has little therapeutic value and is usually done as a cosmetic procedure after debridement and before fluoride application. [ 3 ]

  5. Azo compound - Wikipedia

    en.wikipedia.org/wiki/Azo_compound

    Azo compounds are organic compounds bearing the functional group diazenyl (R−N=N−R′, in which R and R′ can be either aryl or alkyl groups).. IUPAC defines azo compounds as: "Derivatives of diazene (diimide), HN=NH, wherein both hydrogens are substituted by hydrocarbyl groups, e.g. PhN=NPh azobenzene or diphenyldiazene.", where Ph stands for phenyl group. [1]

  6. Tooth discoloration - Wikipedia

    en.wikipedia.org/wiki/Tooth_discoloration

    The stained teeth of a regular betel chewer in Burma. Extrinsic discolorations are common and have many different causes. [10] The same range of factors are capable of staining the surface of restorations (e.g., composite fillings, porcelain crowns). [10] Some extrinsic discolorations that are allowed to remain for a long time may become ...

  7. Enamel microabrasion - Wikipedia

    en.wikipedia.org/wiki/Enamel_microabrasion

    Enamel microabrasion is a procedure in cosmetic dentistry used to improve the appearance of the teeth. Like tooth whitening it is used to remove discolorations of the tooth surface but microabrasion is both a mechanical and chemical procedure.

  8. Tooth whitening - Wikipedia

    en.wikipedia.org/wiki/Tooth_whitening

    The nicotine and tar in tobacco, combined with oxygen, turns yellow and over time will absorb into the pores of enamel and stain the teeth yellow. The dark brown to black stains along the gum line of the teeth are the result of the porous nature of calculus immediately picking up the stains from nicotine and tar. Betel chewing. [12] Betel ...

  9. Dental plaque - Wikipedia

    en.wikipedia.org/wiki/Dental_plaque

    It is commonly found between the teeth, on the front of teeth, behind teeth, on chewing surfaces, along the gumline (supragingival), or below the gumline cervical margins (subgingival). [1] Dental plaque is also known as microbial plaque, oral biofilm, dental biofilm, dental plaque biofilm or bacterial plaque biofilm.