Stress analysis study of two treatment modalities rehabilitating distal extension cases with few remaining natural teeth

الملخص EN

distal extension base removable partial dentures exhibit composite type of support which leads to movement of the denture base under loading.

This movement leads to transmission of high amount of stresses to the abutment teeth.

Many methods were proposed to control and distribute these stresses.

Among which the use of different retainers and splinting of the abutment teeth.

An acrylic experimental mandibular cast of Kennedy class I with only lower anterior teeth remaining was constructed.

This model replicated all the anatomic features of the teeth, their investing structures and the mucosa covering the residual ridges.

Two removable partial dentures (RPDs) were constructed to rehabilitate this case.

The 1st one was extra coronal attachment retained RPD while the 2nd one was telescopic crowns retained RPD.

All the remaining natural anterior teeth were reduced and prepared to receive fixed crowns of the attachment retained RPD or primary copings of the telescopic crowns retained RPD.

The two dentures were having the same components except the direct retainers (either extra coronal attachments or telescopic crowns).

Strain gauge technology was used to assess micro strains induced to the denture supporting structures for the two treatment modalities.

By analyzing the data, the attachment retained RPD design showed more stresses transmitted to the abutment teeth than that of the telescopic crowns retained RPD design.

While more stresses were concentrated on the residual ridge with the telescopic crowns retained RPD design.