A precisely accurate model is one of the most important steps in creating an appliance/retainer that properly fits. Because an invisible retainer adapts so closely to your patient's teeth, it's very important that the model you send to us meticulously represents the patient's dentition/anatomy. This cannot be stressed enough: we can only make an appliance/retainer to fit the model you send us. Any flaws in the model will show up in the finished retainer, resulting in an improper fit.
If at all possible, please send us the model instead of an impression. Discrepancies between the patient's actual anatomy and the impression may not be readily visible in the impression itself— only upon the doctor's inspection of the poured model does the accuracy, or lack of, become more apparent.
Of course, we will pour your models if necessary, but there is a charge for that. In fact, the more time we must spend preparing your models, the more we must charge you.
Trim style refers to both the cut of the retainer's arch length and its shape around the tissue and teeth.
The arch length can be cut to the full arch, 3 to 3, or 4 to 4. The latter two are considered "Essix-style."
You may want the retainer cut straight across the labial surface and scalloped around the gingival margin on the lingual side. Some of our customers prefer a sub-gingival trim on the lingual side.
Up to .040" thickness is suitable for upper and lower arches. The plastic sheets from which we vacuum-form our retainers are available in .020", .025", .030", .035", and .040" thicknesses, depending on the type of material.