According to an embodiment, a method for designing a virtual 3D model of a dental restoration is disclosed. The method includes obtaining a digital 3D representation of a set of teeth of a patient, said digital 3D representation comprising a section corresponding to a target site; determining an insertion path for the dental restoration to the target site; determining a limiting volume of the digital 3D representation. The limiting volume includes a boundary that provides an indication of a space available for the dental restoration when moving along the insertion path. The virtual 3D model of the dental restoration is designed such that virtual 3D model is confined within the limiting volume or within a predetermined offset from the limiting volume.