Model preparation for 3D scanning and computer assisted design (CAD)
For 3D scanning the followings are required:
1. Gypsum model - see the bellow conditions that must be meet
2. Bite registration impression - if the initial bite registration impression is not complete or insufficient, take a bite registration in laboratory using the articulated models (maxillary and mandibular). please do not cut the bite registration impression.
3. Antagonist - the gypsum cast model must have full base, should not be varnished, must be clean.
Preparation for gypsum model that will be scanned.
To allow a precise 3D scan of the gypsum model, this must meet the following:
1. the model must have a base (from plastic, resin, gypsum) and the arch must be mounted on pins (to enable the removable of the neighbours and work abutments). IMPORTANT: the neighbours and work abutments must be removable from the base. Bellow there is an example of a model prepared for 3D scan (gypsum base, pins, anti-rotation retentions).
2. if the models were articulated, the model (just the model base and arch) must be easy to remove from the articulation base.
3. models must be clean
4. the abutments must be separated and individually removable
5. the marginal line must be highlighted (avoid a very thin line, do not use marker, pens, etc. to highlight the marginal line).
6. do not cover the work abutments with spacer, wax etc.
7. do not varnish the models.
8. the neighbours must be removable.
9. the abutments must be retention free (on the insertion axis),specially minimum 1 mm above the marginal.
10. in case of bridges, the insertion axis of the bridge must assure unobstructed insertion of the bridge (retention free), in case there is a insertion issue, this must be fixed before sending the model to be scanned.
Example of a model prepared for 3D scan (pins, anti-rotation retentions)