When confronted clinically with the problem of tooth discolouration, the basic strategy is to first identify the aetiology of the discolouration, and then to apply the selected treatment, using the philosophy as much as required, but as little as necessary. For internal discolourations, green laser light from a KTP or argon laser is able to elicit photochemical reactions both within tooth structure and within a bleaching gel applied onto the labial surface. The unique optical and chemical interactions makes photochemical bleaching possible through promoting oxidation events in a controlled manner. This paper outlines a clinical approach to the diagnosis and management of patients with tooth discolouration, and summarises the technical and clinical aspects of the Smartbleach system for laser whitening. While extremely useful for routine in-surgery whitening treatments, the system is also able to treat severe tetracycline staining, to achieve pleasing improvements in appearance. A case is presented to illustrate the application of the Smartbleach system in these more challenging situations. A simple objective method for assessing tooth shade changes during laser whitening is also described.
Keywords: discolouration, whitening, KTP laser, argon laser, tetracycline