cosmetic dentistry_ beauty & science

34 I I industry report _ tooth whitening _A dazzling white smile has been a symbol of beauty, health and vitality for hundreds of years. Discolouration, especially when the front teeth are affected, means a significant disturbance of aesthetics and can decrease a patient’s self esteem. SDI’s latest in-office tooth-whitening product, Pola Office+, is one of the fastest systems on the market. Its powerful hydrogen-peroxide-based gel and ease of use characteristics along with the clini- cal procedure for whitening of non-vital teeth and the beautiful results of this minimally invasive technique are described in this article (cases I & II). Deepdiscolorationofnon- vitalteethcanbeduetointra- pulpal haemorrhage after trauma. Brown stains, for ex- ample, can be the result of Fe+2 ions reacting with hy- drogensulphide.Additionally, some endodontic filling ma- terials can cause orange-red discolouration and grey-black staining is known to be caused by the corrosion of silver posts. Possible treatment options are discussed below. Thermo-catalystbleachingmethod Thebleachinggelisplacedintothepulpchamber followed by application of a heating source such as a specially designed heating lamp or by using hot instruments directly in the pulp chamber or on the lingual–buccal surface of the tooth. The gel is re- peatedlyappliedandheated.Anuncontrolledrisein temperaturebearstheriskofunwantedsideeffects such as cervical resorption. Therefore, this method is no longer in practice. Walkingbleachtechnique The root filling is removed approximately 2 mm under the dentine–cement line and the bleach- ing mixture is placed in the pulp chamber, sealed and left in situ for several days. A fresh peroxide mixture then replaces the previous mixture in the chamber and the chamber is resealed. This is repeated until the desired result is obtained. This technique is widely accepted and delivers good results. Modernin-officetoothwhiteningtechnique IncaseI(Figs.1&2),PolaOffice+wasusedasin- office bleach. The gel was placed into the chamber and onto the surface of the tooth for the recom- mended time. The gel was then removed and fresh gelre-applied.Thisstepwasrepeatedseveraltimes. Please note: The bleaching gel does not stay in the tooth for several days as is done with the walking bleach technique. The clinical advantages of this technique are discussed in detail below. _Preparation and lingual entry of the cavity The following are the contra-indications for in- ternal tooth whitening: cosmeticdentistry 4_2011 Fig. 1_Pre-treatment, case I. Fig. 2_Post-treatment, case I. Fig. 3_Pre-treatment, case II. Fig. 4_Drawing of the lingual entry of the cavity. Professional in-office whiteningofnon-vitalteeth Author_ Dr Ludwig Hermeler, Germany Fig. 3 Fig. 2 Fig. 1 Fig. 4