Radiogpaphic Evaluation of Residual AlveolaP Ridges Under Distal-Extension Bases of Removable Partial Oentul'es RecoPded by Two DiffePent lmppession Techniques;Mucostatic and MucocompPessive (Aitered-Cast Technique)

Abstract

The disparity of support is the main problem facing the success or failure of distal-extension removable partial dentures. This problem gave rise to various philosophies, one of which is the functional basing.

Twenty partially edentulous patients were chosen, according to definite criteria of patients' selection, to have lower bilateral distal­ extension residual ridges opposing upper completely edentulous ridges.

After thorough oral examination and mouth preparation, a lower metallic distal-extension removable partial denture opposing an upper acrylic one were constructed for each patient.

The steps of denture construction were the same for all patients except that of secondary impression technique. In one group of patients, the mandibular arch was recorded with mucostatic technique using alginate impression material. In the other group, the distal-extension ridges were recorded following Applegate's altered-cast procedure with rubber base impression material.

The biologic effect of using two different secondary impression techniques was studied by radiographic evaluation of the supporting bone at two sites; under distal-extension bases and proximal to the principal abutment teeth.

Periapical radiographing (parallel technique) of the patients was made at the delivery time (the base line) and after; six, twelve and eighteen months of denture wear.