cosmetic dentistry_ beauty & science

38 I I industry report _ direct composite resin restorations _The ability to create highly aesthetic direct composite resin restorations in a simplified manner haslongbeenagoalfordentists.Inthepast,difficul- tieswithdirectcompositeresinshaveincludedshade matching, handling properties, premature setting under operatory lights, and overall ease of use. This articlewilldescribeacompositeresinsystem(Amaris, VOCO) that has demonstrated desirable properties for use in both posterior teeth and especially in the aestheticzone.Thereafter,acasereportdemonstrat- ing the use of the material will be presented. _Two-step shade matching concept Toothcolour,withitsvaryingshadesandtranslu- cencies, is difficult to achieve between composite systems; for example, resins based on the porcelain VITA Classical shade guide (Vident) cannot achieve the desired results with consistency. Most compos- ite systems work on the principle of matching com- posite to the basic shade ranges found in dentine and enamel. In order to create the polychromatic effect found in natural enamel and dentine, several things must happen. To mimic the optical properties of hydroxyap- atite enamel rods, composite resin must create the illusion of the way light is reflected in the natural tooth. Dentine is by nature opaque, providing teeth with their basic shades of yellow, brown, gray and blue. Enamel is by nature a white–translucent shade, providing teeth with their natural value. cosmeticdentistry 4_2011 Fig. 1_Pre-op situation: maxillary anterior teeth were discoloured, fractured and sensitive. Fig. 2_Stained enamel was removed and a scalloped margin prepared. Fig. 3_Margins were created at the interproximal surfaces of both teeth. Fig. 4_A dual-cure, self-etching bonding agent (Futurabond DC) was applied. Simplifying direct composite resin restorations in the aesthetic zone Author_ Dr Ian E. Shuman, USA Fig. 4Fig. 3 Fig. 2Fig. 1