title: Photoelastic analysis of the influence of residual ridge inclination in conjugated class I mandibular prostheses with different attachment systems.
abstract: OBJECTIVE
  The aim of this study was to evaluate the stress distribution in mandibular free-end removable partial dentures (RPD) associated with FPD in the abutment teeth considering different inclinations of the residual ridge: (1) horizontal and (2) distal descending ridges and two designs of free-end RPD with different attachment systems were tested: (1) clasp and (2) system ERA.
  
  
  METHODS
  Axial loads (100 N) were applied on the teeth of the RPD. The images were recorded and the stress distribution was evaluated through photoelastic fringes.
  
  
  RESULTS
  In general, the distal descending ridge presented more photoelastic fringes in the region of the roots of the abutment teeth while the horizontal ridge exhibited higher compression in the base of the prosthesis. In the horizontal ridge, the denture with clasp presented more favourable stress distribution than the denture with the system ERA. In the distal descending ridge, the denture with the system ERA relieved the region of the abutment teeth and overloaded the residual ridge.
  
  
  CONCLUSIONS
  The horizontal ridge presented more favourable performance; the dentures with clasp exhibited better performance for both ridges evaluated; the denture with the system ERA presented better results in the distal descending ridge.
authors: Araçatuba Dental School, São Paulo State University-UNESP, São Paulo, Brazil.
authors: Renato
authors: R
authors: Ferraço
authors: Eduardo Piza
authors: EP
authors: Pellizzer
authors: Bianca Piccolotto
authors: BP
authors: Tonella
authors: Rosse Mary
authors: RM
authors: Falcón-Antenucci
authors: Fellippo Ramos
authors: FR
authors: Verri
authors: Stefan Fiúza de Carvalho
authors: SF
authors: Dekon
authors: Marcelo Coelho
authors: MC
authors: Goiato
mesh_terms: D000044:Dental Abutments; D003799:Dental Stress Analysis; D008341:Mandibular Prosthesis