title: Photoelastic stress analysis in a pier retainer of an anterior resin-bonded fixed partial denture.
abstract: BACKGROUND
  A clinical situation may arise with 2 edentulous spaces and a single intact pier tooth. A dentist may restore these edentulous spaces with a long span resin-bonded fixed partial denture using the pier and the 2 terminal abutments for bonding.
  
  
  OBJECTIVE
  This study analyzed the stresses induced in a pier retainer of an anterior resin-bonded fixed partial denture and determined the effect on a pier abutment.
  
  
  METHODS
  Photoelastic materials were selected to represent the relative stiffness of 3- and 5-unit resin-bonded fixed partial dentures. The models were scaled to x2.5 to enhance visual analysis of the stress pattern.
  
  
  RESULTS
  Isochromatic fringes indicated a stress magnitude at the proximolingual areas of the pontic in the 3-unit resin-bonded fixed partial denture. In the 5-unit resin-bonded prosthesis, the stress pattern appeared to involve the entire surface of the pier retainer.
  
  
  CONCLUSIONS
  The use of pier abutments should be avoided and it is more favorable to use 3-unit resin-bonded fixed partial dentures.
authors.affiliation: University Dental School and Hospital, University College Cork, Cork, Ireland.
authors.forename: H M
authors.initials: HM
authors.lastname: Ziada
authors.forename: J F
authors.initials: JF
authors.lastname: Orr
authors.forename: I C
authors.initials: IC
authors.lastname: Benington
mesh_terms: D000044:Dental Abutments / Q000706:statistics & numerical data; D003799:Dental Stress Analysis / Q000379:methods* / Q000706:statistics & numerical data; D003779:Denture Design / Q000379:methods* / Q000706:statistics & numerical data; D016379:Denture, Partial, Fixed, Resin-Bonded / Q000706:statistics & numerical data; D004548:Elasticity; D006801:Humans; D008027:Light; D003765:Models, Dental; D013696:Temperature