Long term research data on dental porcelain veneers have demonstrated the need to retain as much enamel as possible during the preparation phase. With this in mind, the preparation process has evolved through 3 distinct generations. 1) Arbitrary controlled depth cuts of the remaining tooth substance: but this inevitably extends through to dentin creating potential predictable long term bonding issues. 2) Wax up the desired new tooth form extending slightly labially (0.25mm) and develop silicone indices/matrices to evaluate controlled intra-enamel preparation relative to new position- ing of teeth: a good system but time consuming and complex. 3) Use of a wax up and silicone stent to develop a trial smile directly in the mouth: allows evaluation of function and esthetics.