CDE0111

08 I I clinical technique _ fractured maxillary central incisors cosmeticdentistry 1_2011 _Diagnostic wax-up and silicone index At the next appointment the following week, the gingivitis had resolved but the composite build-up on the left central incisor had detached from the remaining tooth substrate (Figs. 5–7). In order to prevent sensitivity and bacterial in- vasion, the exposed dentine on the left central incisorwasetchedwith37%phosphoricacidfor 20 seconds and immediately sealed with a den- tine-bonding agent (OptiBond Solo Plus, Kerr). The gingival condition had improved follow- ing prophylaxis and oral-hygiene instruction, and upper and lower impressions were taken using an accurate, soft, distortion-free material (AlgiNot FS, Kerr). Concurrently, reference pho- tographs were taken with VITA Classic and VITA 3D Shade Guides (VITA) for shade analysis (Figs. 8 & 9). The impressions were cast with hard plaster forthediagnosticwax-up.Thepatientwasasked to supply photographs of his teeth prior to the accident (Fig. 10), which are an invaluable guide for assessing tooth anatomy and for guiding the dental technician during the wax-up process. The patient displayed a large overjet of 7 mm, which obviously places the central incisors in a precarious situation, highly susceptible to traumatic injury (Fig. 11). In the dental laboratory, the preoperative models of the fractured incisors were waxed-up to the proposed facial and palatal morphology (Figs. 12–17). An index was fabricated, using a heavy body, addition silicone impression ma- terial and sectioned at the incisal edge, ensuring that a ledge was present at the incisal edge to support the intra-oral composite build-up (Figs. 18 & 19). _Composite build-up on the left central incisor Choice of composite The two basic criteria for selecting an appro- priate composite filling material are satisfaction of function (resilience, mechanical and thermal properties) and aesthetics (replicating enamel, dentine and characteristics such as translu- cency, opalescence and fluorescence). In this instance, the new Herculite XRV Ultra (Kerr) was chosen for its superior mechanical and op- tical properties. Herculite XRV Ultra is a nano- hybrid composite, updated from its predecessor Herculite XRV, which was introduced over two decades ago. The endearing feature of nano-composites is the very small particle size of the filer, 25 to 75nmsmallerthaninmicro-hybrids.Thereduced filler size particles confers superior aesthetics by allowing excellent surface gloss after polish- ing, as well as advantageous optical properties, such as opalescence and fluorescence. In ad- dition, Herculite XRV Ultra offers favourable wear resistance, compressive strength, fracture toughness and flexural strength with good adaptability, sculptability and thixotropic prop- erties. Furthermore, it is available in a large range of enamel, dentine and incisal shades for Fig. 14_Facial view of diagnostic wax-up. Fig. 15_Right lateral view of diagnostic wax-up. Fig. 16_Left lateral view of diagnostic wax-up. Fig. 17_Incisal view of diagnostic wax-up. Fig. 18_Facial view of diagnostic wax-up with silicone index in situ. Fig. 19_Facial view of diagnostic wax-up and palatal aspect of silicone index, showing the palatal anatomy with incisal ledge to support the intra-oral composite build-up. Fig. 15 Fig. 16Fig. 14 Fig. 18 Fig. 19Fig. 17