10 - Removable devices and facial epithesis prostheses

Abstract

Although fixed prosthodontics plays an important role in rehabilitation of partially edentulous jaws, there is still the need for conventional removable partial dentures and complete dentures as well as maxillofacial prostheses. The majority of removable dentures are made from acrylic resin of polymethylmethacrylate (PMMA). The importance of using removable dentures will become even greater in the coming decades due to a progressive demographic ageing of the population with the need for transitional and long-term provisional prosthodontic devices. Age-related changes of the masticatory system include wear of teeth, loss of teeth, and changes of the oral mucosa and bone structures. All these are in relation to the capability of wearing removable dentures and to the potential technical failures of denture constructions due to changes in fit of the dentures and formation of stress concentrations in the denture, which can break the denture. Denture base and denture teeth resin materials will age and their physical properties change over time. This in combination with continuous dynamic loading conditions provokes denture failures, which are typically fatigue fractures of denture bases and loosening of denture teeth. Also impact types of denture failures may occur when the denture is accidentally dropped on a hard surface.