Abstract
Current tooth lightening systems use hydrogen peroxide or carbamide peroxide which releases hydrogen peroxide as the bleaching agent. In vitro and in vivo studies, mostly comparing different bleaching systems, have demonstrated the efficacy of vital and non-vital tooth bleaching. Bleaching treatments are affected by a number of factors including the actual cause of tooth discoloration. All in-surgery bleaching agents are chemically activated and, whilst better results are possible with lights, these are not essential. Shade change can be evaluated subjectively and may be observed after only a few nights with Night Guard Vital Bleaching (NGVB). Objective methods of shade evaluation are used in most randomized controlled trials. There are a number of methods used to bleach teeth but NGVB using 10% carbamide peroxide in trays produces the optimal result with the least side-effects. The ‘inside/outside’ bleaching technique using 10% carbamide peroxide is the most effective and safest method of bleaching non-vital teeth. Although more than 90% success has been reported, regression of the colour change is a common problem in vital and non-vital tooth bleaching and retreatment is necessary in many cases, usually after 1–3 years. The overwhelming evidence indicates that tooth bleaching is effective if supervised by a dentist.
