Impressions for Retainers
Usually you are taking impressions for study models at the same time as removing the patinets removable appliance. In this case it is not normally necsaary to take seperate impressions for the appliance.
However, if you are taking an impression only for the construction (or repair) of a retainer appliance. You only need to take an impression of the arch for which the retainer is being fitted.
There are 3 types of retainers in common use:
- Hawley retainer - you need a good impression of the arch to be retained
- Essix retainer - you need good buccal and lingual sulcus depth on the impression
- Bonded retainer - you must ensure good detail is recorded of the lingual/palatal surface of the teeth to be bonded