Abstract: A dental preparation block guide comprises a chamber that is customized to receive at least one tooth of a patient for a shape-optimized restoration of the at least one tooth; and a channel formed in a surface of the block guide at a location selected relative to the shape-optimized restoration to be performed, the channel comprising an aperture extending through the surface to the chamber such that a dental handpiece can be inserted into and guided within the channel while a tool of the dental handpiece can interact with the at least one tooth in the chamber through the aperture to form a shape-optimized preparation in the at least one tooth to receive the shape-optimized restoration. Related methods and system, as well as other devices, also are disclosed.