Ultimately, true smile designers must be masters of many principles including mathematic, physical, chemical, biological and technical. If any one of these is either neglected or miscalculated, it will affect the final result in some way ranging from color to shape to durability. Many dentists who perform cosmetic dentistry have not been properly trained or do not have the sufficient amount of experience to predictably perform any and all smile design and full mouth rehab cases on anyone. That's how they get in trouble with cases that fail prematurely, never look right from the beginning and are never comfortable. That is why we post the most comprehensive gallery of before and after cases online and have some of the best reviews online unsolicited.