Trimming Appliances

Using the Essix Mayo scissors, trim away the excess plastic leaving tabs on the lingual and the labial. Then using the Essix Lab knife or Trim-Rite® electric knife, trim away the distal ends.

No matter which tool is used, make sure to start cutting from the incisal edge and cut toward the base.

Make sure all the plastic is removed from the distal end. Then, pulling the lingual and labial tabs at the same time, the cast will drop out of the plastic.

Take a look at this diagrammatic to see how the appliance should look from all sides after final trimming.

In order for the patient to remove the appliance, the disto-gingival should be trimmed away. Again, using the Mayo scissors, cut straight from canine to canine on the lingual. Then cut across the labial, approximately 1cm onto the gingiva. cut up towards the incisal edge of the canine, rounding out the edges.

The full arch appliance is a little trickier to remove without breaking the cast. Most importantly, cut away the distal third of the terminating molar using the Trim-Rite electric knife. Depending on the plastic being used, the Trim-Rite knife should be set properly. If the tool is too hot, the plastic will fray, leaving a very rough edge that will need to be trimmed again with scissors.

To cut the outline of the appliance, directly on the model, use the Essix wheel saw, on the lingual and labial, trimming approximately 1cm onto the gingival. Or use the Trim-Rite knife to trim the same way – 1cm onto the gingival. Use the Essix cast-removing instrument to gently pry the plastic from the cast, working from the molars toward the canines. Inspect the trimmed edges; if they feel too rough try smoothing them out with Raintree's border polishers. Keep in mind, however, that fingertips are much more sensitive than gums. So, what feels rough to the clinician, may not in the patient's mouth.

For clinicians concerned with full coverage appliances inducing an open bite, eliminate high spots on the appliance. Have the patient bite down on double-sided articulating paper with the appliance seated. Using the Raintree trimming bur, grind away the marked high spots.

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