Given these clinical assumptions, dentists periodically need to evaluate the fit of their patients’ removable prostheses. A key criterion to be employed in such an examination is the evaluation of the prosthesis for "maximal intimate contact of the denture base and its basal seat."² Other factors that also need to be taken into consideration include the patient’s medical and dental histories, assessment of the clinical stability and retention of the prosthesis, health of the basal tissues, status of existing denture-base resin and dentures, vertical dimension, and cosmetic, functional, and physiological considerations.³

As a general practice dentist who provides periodic examinations for the patients of two full-time dental hygienists, I have found that I sometimes need to be able to accurately and quickly assess the accuracy of fit of my patients’ existing removable partial and complete dentures. Clinical experience has taught me that if I wait until the patient complains of a "loose" prosthesis, I have waited too long.

For instances in which I am unsure if a reline is indicated, I have devised a simple, inexpensive, quick technique to accurately determine the fit between the denture base and its basal seat. This technique also is extremely useful as a patient education tool, as patients can readily see if their dentures fit their oral tissues well.

TECHNIQUE
When I determine that the fit of a denture base to the basal tissues needs to be examined, I explain to the patient that it is important for the health of his or her oral tissues to have well-fitting dentures.

With the patient’s consent, I take a reline-type impression inside the questionable prosthesis using a low-viscosity, hydrophilic, fast-setting vinyl polysiloxane, or VPS, impression material. (I prefer to use a light body material that sets rapidly.) To ensure that cleanup is easy, I do not use adhesive impression materials. I also do not adjust the denture base before the impression material is placed. This is not a final impression for a reline; instead, it is a diagnostic impression that I use to assess the fit of the denture base against the basal tissues (Figure).

View larger version (105K): [in this window] [in a new window]   Figure. Photograph of a rapidly obtained diagnostic impression.

To determine if this is a valid diagnostic test, on several occasions I have checked the fit of a prosthesis on delivery of the reline or a couple of weeks after the reline is delivered. I also have used this technique to test relatively new prostheses that were performing very satisfactorily for the patient. In both situations, I found that this diagnostic reline impression technique is a valid way to evaluate the fit of the prosthesis to the oral tissues.

CONCLUSION
I have been using this technique for one year and have found it to be well-tolerated by my patients. It allows me to determine accurately whether patients will benefit from a reline of their existing prostheses without a large investment of time or materials.

DO YOU HAVE A TIP TO SHARE?
Do you have a time- or work-saving clinical technique to share with your colleagues? Submit it to JADA’s Clinical Directions department. A Clinical Directions item should be a maximum of two double-spaced typed pages and should include no more than one figure or illustration. Submit items to Clinical Directions, JADA, 211 E. Chicago Ave., Chicago, Ill. 60611.