Stress distribution with extra-short implants in an angled frictional system: A finite element analysis study

Abstract

Statement of problemShort and extra-short implants with Morse taper connections were developed to avoid grafting procedures. How the stresses around these implants differ with abutments of different angulations is unclear. PurposeThe purpose of this finite element study was to analyze the stress distribution in different structures (abutment, implant, and bone) of an extra-short implant with a Morse taper connection to the abutment (Arcsys-FGM-Brazil) (5.0×5.0 mm and 4.3×5.0 mm) when different abutment degrees were used. Material and methodsEight 3D models were designed according to each group under analysis: group 5DS (5.0×5.0-mm implants with straight abutment), group 5DA (5.0×5.0-mm implants with 20-degree angled abutments), group 4DS (4.3×5.0-mm implants with straight abutments), and group 4DA (4.3×5.0-mm implants with 20-degree angled abutments). Axial and oblique loads of 150 N were applied on the mandibular molar crowns. ResultsThe oblique loads and angled abutments had higher stress values in the whole model (implant, abutment, and bone) than the axial loads and straight abutments. Implants with a different diameter had almost the same stress distribution on the implant, abutment, and bone. The yield limit was exceeded in the cortical bone with oblique loads and was also exceeded in implant models when an angled abutment with oblique loads was used. ConclusionsExtra-short implants with Morse taper connections to the abutment had higher stress concentrations with an angled abutment on oblique loads, and the peri-implant bone was the most damaged structure.