Ultra-thin porcelain veneers look primarily at the restorative space, so-called restorative space is made for the creation of restorations. If the patient bites deep coverage, like this if the bite is less than, simply change the color, is not required to grind the teeth. Of course, some teeth, such as fluorosis, if you do ultra-thin veneers, you need to gently sand off the yellow plaque of coloring on the surface of the teeth, and then take the model to make it after it is sanded off. So depending on the teeth, depending on the color or the bite, different patients can choose whether or not they need tooth preparation.