When you have a deleted mandibular ridge, you may end up with a thin tray buccolingually. You can prevent breakage by adding a spine of acrylic along the crest of the ridge, extending the spine right to the handle. This strengthens the tray and also lifts your finger preventing it from becoming part of the denture impression.

10. Notice how the additional acrylic on the right side strengthens the tray and "lifts" the finger away from the tray borders.

If your finger is too close to the tray border (not even touching it), then the impression material will follow around your finger, making a circular and obviously incorrect impression.

	10. Note imprint where fingers were placed to seat the tray.
	10. Note small white pointer showing area of distortion on right distobuccal border.
	10. Enlarged view of  right distobuccal border.

©1999 by Julius Rosen, D.D.S.