Clinical Evaluation of the New Prosthesis

Maxillary Denture Retention

Retention of the upper denture can be assessed by two methods. When the denture is grasped by the incisors and pulled downward between thumb and forefinger, there should be resistance to displacement. Placing fingers on the palatal surface and pulling forward is a second method for checking retention. Again, there should be resistance to displacement. However, if the denture begins to drop but then holds well, this indicates that air is being trapped under the denture base upon placement. A likely cause for this action is overextension, which if left uncorrected, will cause ulceration within a matter of hours or days or a complaint that the denture drops when smiling or when opening the mouth widely.
To check lateral stability, the operator should place light pressure on the occlusal surfaces of one quadrant of posterior teeth to determine if the denture dislodges on the opposite side. Poor stability may not be able to be corrected if the maxillary posterior teeth had to be set buccal to the ridge crest for anatomic, esthetic, or occlusal reasons. The dentist needs to anticipate this and caution the patient to chew bilaterally whenever possible.

Retention of the Mandibular Denture

The retention of the lower denture is assessed by gently pushing posteriorly against the facial surfaces of the mandibular incisors. The denture should not become dislodged.
Pressure indicator paste should be used to recheck the adaptation to the bearing tissues of both upper and lower prostheses, even if retention seems acceptable. Small areas of excess pressure can disrupt occlusal harmony or lead to ulceration that erodes patient acceptance of the prosthesis.