Model Examples
Examples of a model that may cause an appliance to not fit.
Note: Stone models are preferred over plaster as they are less likely to break during shipping.
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Potential Causes
- Alginate pulled away from tray
- Tray removed before alginate completely set up
- Use enough material in tray for accurate impression of teeth
- Impression removed from tray before alginate was completely set up
- Void in alginate material caused by not enough alginate in the tray
- Impression tray moved before alginate was completely setup
- Alginate not mixed thoroughly
Example of a good model.
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- Minimal chips, bubbles, or porosity on the occlusal surface
- No Narrowing or pinched appearance of incisal, buccal, or lingual cusps