3D scanning and 3D printing can be treated as opposite directions of the same workflow: scanning moves a physical object into the digital world, while printing turns digital geometry back into a physical object.
Scanning is usually the beginning, not the finished model
Raw scan data often contains noise, holes, unwanted background geometry and inconsistent topology. It can be excellent reference material, but most production uses require cleanup before the mesh is ready for rendering, measurement, modification or printing.
Decide what accuracy you actually need
A decorative object, a mechanical replacement part and a visualization asset do not need the same workflow. Sometimes preserving surface irregularities matters; in other cases the scan is only a dimensional guide for rebuilding cleaner geometry.
Mesh cleanup and reconstruction
Typical steps include removing disconnected fragments, filling holes, correcting normals, simplifying overly dense areas and rebuilding parts that scanned poorly. For hard-surface objects, retopology or direct remodeling can often produce a cleaner and more editable result than trying to repair every scan triangle.
Preparing the model for printing
A printable model should be watertight, have appropriate wall thickness and avoid problematic self-intersections. Scale must also be verified, because a model that looks correct on screen can still fail physically if dimensions or tolerances are wrong.
Where this workflow is useful
Scanning and printing can support prototyping, reverse engineering, replacement parts, preservation, custom fittings, miniatures, decorative objects and visualization. The most efficient workflow depends on whether the final goal is measurement, editing, rendering or physical production.