cosmetic dentistry_ beauty & science

36 I I industry report _ Tetric EvoCeram _A very close inspection of dental enamel reveals its intricate fabric. Reproducing these fine structures and shade nuances seems a daunting task.Owingtotheresearchanddevelopmentefforts of dental composite manufacturers over the past few years, materials are now available that greatly facilitate the placement of restorations. Neverthe- less, the appearance of composite resin restora- tions is often marred by a greyish shimmer. The fol- lowing clinical case shows a way to avoid this problem and realise the natural-look- ing results envisioned by the patient. An 11-year-old male pa- tient presented to our sur- gery with a fractured central incisor (Fig. 1). The clinical examination revealed that the tooth was sensitive to temperature and percus- sion. A fracture close to the pulp was diagnosed (Fig. 2). Clinical evidence of a pe- riodontal trauma was not found. I recommended that the tooth be reconstructed by layering composite resin using a minimally invasive and conservative restorative technique. _Shade selection I determined the shade in daylight at the begin- ning of the treatment before the teeth were dried. I used the shade guide of the com- posite resin, which I sub- sequently used during the restorative procedure (Tetric EvoCeram,IvoclarVivadent). In order to check the select- ed tooth colour, I applied a composite layer to a tooth and polymerised it. For the cervical area, I chose dentine shade A2 and for the incisal area, enamel A1. _The mock-up The treatment area was locally anaesthetised and the tooth was reconstructed free-handedly using a composite resin (deviating from the tooth colour), without preparation or the application of an adhesive. I decided to use an easily recognisable shade, in this case A4 (Fig. 3). After polymerisation, the shape and exact position of the margin and the occlusion were refined. Finally, a silicone matrix of the palatal surface and the margin was fabricated with a putty impression material. This matrix would facilitate the subsequent layering procedure. After thefabricationofthesiliconematrix,theprovisional restoration (mock-up) was removed. Later, a com- posite resin in the desired tooth colour would be placed. _The cementation protocol When the adhesive is applied to the restoration, it is important to ensure that the tooth surface is not too wet. The placement of a rubber dam with ligatures is standard procedure. The rubber dam provides an unobstructed view of the treatment field and increases the safety and comfort of the practitioner and the patient. Thetoothsubstancewaspreparedwithafeather edge in the labial enamel. This preparation design ensures tight sealing and forms the basis for an unobtrusive transition between the natural tooth structure and the composite resin (Fig. 4). The enamel and dentine were cleaned with a 0.2 % mix- ture of pumice and pure chlorhexidine (PAROEX, GUM). Next, Telio CS Desensitizer (Ivoclar Vivadent) was applied. Owing to the wide enamel edge, the Total Etch technique(IvoclarVivadent)wasusedinthepresent case. That is, the tooth was etched with phosphoric acidbeforetheadhesivewasapplied.Therefore,the enamel was etched for 30 seconds and the dentine cosmeticdentistry 4_2011 Anterior tooth restoration― An exciting experience Author_ Dr David Hacmoun, France Fig. 2 Fig. 3 Fig. 1 Fig. 4 Fig. 1_Pre-op view, showing fractured central incisor. Fig. 2_Considerable loss of dental enamel; fracture line near the pulp. Fig. 3_Mock-up made of composite resin (A4) for the palatal silicone matrix. Fig. 4_Preparation of a feather edge under rubber dam isolation.