title: Digital image correlation analysis on the influence of crown material in implant-supported prostheses on bone strain distribution.
abstract: OBJECTIVE
  A digital image correlation (DIC) method for full-field surface strain measurement was used to analyze the effect of two veneering materials for implant supported crowns on the strain distribution within the surrounding bone.
  
  
  METHODS
  An epoxy resin model of a bone block was made by housing acrylic resin replicas of a mandibular first premolar and second molar together with threaded implants replacing the second premolar and first molar. Porcelain-veneered (G1 and G3) and resin-veneered (G2 and G4) screw-retained splinted crowns were fabricated and loaded with (G1 and G2) and without (G3 and G4) the presence of the second molar replica. A 2-dimensional DIC measuring system was used to record surface deformation of the bone block model at a frequency of 1.0 Hz during application of a 250-N load.
  
  
  RESULTS
  Maximum compressive strains (ɛ(XX), %) were found for the following regions: between molars, G1 (-0.21), G2 (-0.18), G3 (-0.26), and G4 (-0.25); between implants, G1 (-0.19), G2 (-0.13), G3 (-0.19), and G4 (-0.14). The magnitude of strains in the simulated bone block with the resin-veneered crowns was lower than that with porcelain-veneered crowns, irrespective of the presence or absence of the second molar.
  
  
  CONCLUSIONS
  The softer resin veneer helped to spread the load more evenly amongst the supporting teeth and implants, thus reducing the strains in the simulant bone block. Conversely, using the harder porcelain veneer resulted in the load being concentrated within one or two teeth or implants, thus leading to higher strain values in the bone block.
authors.affiliation: Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Av. do Café, s/n-Monte Alegre, Ribeirão Preto, São Paulo 14040-904, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Tiossi
authors.forename: Lianshan
authors.initials: L
authors.lastname: Lin
authors.forename: Heather Joan
authors.initials: HJ
authors.lastname: Conrad
authors.forename: Renata C S
authors.initials: RC
authors.lastname: Rodrigues
authors.forename: Young Cheul
authors.initials: YC
authors.lastname: Heo
authors.forename: Maria da Gloria Chiarello
authors.initials: Mda G
authors.lastname: de Mattos
authors.forename: Alex Sui-Lun
authors.initials: AS
authors.lastname: Fok
authors.forename: Ricardo Faria
authors.initials: RF
authors.lastname: Ribeiro
mesh_terms: D001842:Bone and Bones / Q000502:physiology*; D003442:Crowns; D015921:Dental Implants; D003764:Dental Materials; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods*; D003801:Dental Veneers; D003830:Denture, Partial, Fixed; D006801:Humans; D012117:Resins, Synthetic; D013314:Stress, Mechanical
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D012117:Resins, Synthetic