Periodontal problems associated with use of distal extension removable partial dentures--a matter of construction?

It is commonly assumed that a distal extension partial removable dentures rotates around the supporting rests when the saddle is occlusally loaded and that this rotation may expose the abutment teeth to a distal torque believed to be potentially harmful to their periodontal tissues. Attempts are therefore often made to counteract this effect through the denture construction. However, a review of relevant literature does not appear to substantiate an unqualified acceptance of the above mentioned assumptions, nor of the beneficial effect of special denture constructions designed to reduce the abutment loading. On the other hand, well controlled longitudinal studies seem to indicate that a favourable periodontal prognosis may be expected in such cases provided the following conditions are satisfied: Periodontal problems should be treated and an adequate oral hygiene established prior to the insertion of the denture; The periodontal health and oral hygiene should be maintained through regular recalls. During these recalls possible prosthodontic defects should be diagnosed and necessary measures implemented.