Figure 1. Before and after tooth whitening. Tooth whitening or tooth bleaching is the process of lightening the color 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 color of the tooth enamel.[2] The chemical degradation of the chromogens within or on the tooth is termed as blea
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