Earlier posts have discussed the difference in light and color properties between natural tooth structure (enamel & dentin) and their corresponding composite replacements. The difference in translucency, opacity and how the thickness of each layer impacts these properties and others like chroma and value become a challenge chairside when we try and replicate nature. One of the ways to understand and maximize the properties of the composite you are using is a simple bench top exercise. First create a silicone lingual matrix from a model of a patients upper anterior teeth. Next using the current composite that you would employ for a class four or anterior veneer you simply need to create a few teeth and play with the layers and their relative thicknesses.
I always layer from the lingual to the labial, starting with a .5mm layer of enamel composite. Next add in the dentin layers. If you are trying to create a natural chroma gradient for a tooth that will ultimately be A1, place an increment of A3 sloping from the gingival to the incisal. Next a layer of A2 that begins more incisally then the last and slopes to the incisal and lastly a layer of A1 that ends in dentinal lobes based on the age of the tooth you are creating.
This is also a great way to play with adding incisal effects like opal composites, or characterization for craze lines or decalcification spots between the dentin layer you have created and the final enamel layer. Finish with a layer of enamel and the interproximal enamel. With a single matrix you can make a number of composite incisors varying the way you layer the composite to create a gradient or monchromatic result, with no or lots of effects and characterization.
This time at the bench will take what you can accomplish for your patients to the next level and give you a working knowledge of the composite you are using.