Photoelastic Analysis of Cemented or Screwed Implant-Supported Prostheses With Different Prosthetic Connections
The aim of this study was to evaluate the stress distribution of different retention systems (screwed or cemented) associated with different prosthetic connections (external hexagon, internal hexagon, and Morse taper) in 3-unit implant-supported fixed partial dentures through photoelasticity. Six models were fabricated with photoelastic resin PL-2, and each model contained two implants of 4.0 × 10.0 mm. The models presented different retention systems (screwed and cemented) and different connections (external hexagon, internal hexagon, and Morse taper). The prostheses were standardized and fabricated in Ni-Cr alloy. A circular polariscope was used and axial and oblique (45°) loads of 100 N were applied in a universal testing machine. The results were photographed and analyzed qualitatively with a graphic software (Adobe Photoshop). The screwed retention system exhibited higher number of fringes for both axial and oblique loadings. The internal hexagon implant presented better and lower stress distribution for both cemented and screwed prostheses. The oblique loading increased the number of fringes in all models tested. The cemented retention system presented better stress distribution. The internal hexagon implant was more favorable according to the biomechanical standpoint. The oblique load increased stress in all systems and connections tested.Abstract
Figure 1. (a,b,c) Axial loading on the premolar, pontic, and molar on screwed 3-unit fixed partial denture with external hexagon connection. Figure 2. (a,b,c) Axial loading on the premolar, pontic, and molar on screwed 3-unit fixed partial denture with internal hexagon connection. Figure 3. (a,b,c) Axial loading on the premolar, pontic, and molar on screwed 3-unit fixed partial denture with Morse taper connection.
Figure 4. (a,b,c) Oblique loading on the premolar, pontic, and molar on screwed 3-unit fixed partial denture with external hexagon connection. Figure 5. (a,b,c) Oblique loading on the premolar, pontic, and molar on screwed 3-unit fixed partial denture with internal hexagon connection. Figure 6. (a,b,c) Oblique loading on the premolar, pontic, and molar on screwed 3-unit fixed partial denture with Morse taper connection.
Figure 7. (a,b,c) Axial loading on the premolar, pontic, and molar on cemented 3-unit fixed partial denture with external hexagon connection. Figure 8. (a,b,c) Axial loading on the premolar, pontic, and molar on cemented 3-unit fixed partial denture with internal hexagon connection. Figure 9. (a,b,c) Axial loading on the premolar, pontic, and molar on cemented 3-unit fixed partial denture with cone Morse connection.
Figure 10. (a,b,c) Oblique loading on the premolar, pontic, and molar on cemented 3-unit fixed partial denture with external hexagon connection. Figure 11. (a,b,c) Oblique loading on the premolar, pontic, and molar on cemented 3-unit fixed partial denture with internal hexagon connection. Figure 12. (a,b,c) Oblique loading on the premolar, pontic, and molar on cemented 3-unit fixed partial denture with Morse taper connection.
Contributor Notes