Teeth Whitening is a cosmetic dentistry procedure where discoloured teeth are ‘whitened’ to a lighter shade using certain safe-to-use chemicals. Results of the treatment typically depend on how sever the discolouration is. For example, individuals with teeth shade A2 or lower show the most improvement with teeth whitening treatments and the results are easily visible. Both front and posterior teeth can be whitened. The procedure is completely safe when carried out under professional supervision and can sometimes take several visits to complete depending on what treatment option is chosen.