A Digital Image Correlation Analysis of Strain Generated by 3-Unit Implant-Supported Fixed Dental Prosthesis: An In Vitro Study

OBJECTIVE: To evaluate the influence of different veneering materials (porcelain and resin) and implants (short and conventional) in the strain distribution of implant-supported splinted fixed partial dentures (FPDs) using digital image correlation (DIC). MATERIAL AND METHODS: Four polyurethane models were fabricated with resin replicas (first premolar) and short and/or conventional implants replacing the second premolar and first and second molars, according to the following configurations: G1, 2 conventional (second premolar and first molar) and 1 short (second molar) implant; G2, 1 conventional (second premolar) and 2 short (first and second molar) implants; G3, 3 short implants; G4, 3 conventional implants. Porcelain- and resin-veneered splinted FPDs were screwed to the implant abutments. The DIC system was used to calculate strains during application of occlusal load (250 N). RESULTS: Porcelain- and resin-veneered showed similar strain distribution for all groups (P > 0.05). Concentration of compressive strains was higher in G3P and G3R with maximum compressive strains of -1271.50 and -1026.88 μs, respectively. G4 transferred the best strain distribution (porcelain, -275.14 μs; resin, -254.44 μs), followed by G2 (porcelain, -306.79 μs; resin, -310.63 μs). CONCLUSION: The veneering material used did not influence the strain distribution. In addition, conventional implants generate less strain concentration, although the combination of 2 short and 1 conventional implant seems to be a viable plan.