Objectives: This study evaluated the effect of different angulations of posterior implants in all-on-four treatment concept when using glass fiber reinforced composite (GFRC) framework in comparison to titanium framework material.
Materials and methods: Three-dimensional finite element model of completely edentulous mandible was simulated using cone beam computed tomography. Six different models were created and restored according to all-on-four treatment concept. The six models were created by using three different angulations of the posterior dental implants; 15°, 30° and 45° and using two different framework materials; titanium (Ti) framework and glass fiber reinforced composite (GFRC) framework. At the end of the cantilever part of the frame work, unilateral load of 250N were applied and the resultant von Mises stresses at the implant/crystal bone interface were calculated.
Results: The Ti framework produced lower stresses in comparison with GFRC framework within the same distal implant angulation. Moreover, increasing the tilting of the posterior dental implant developed more stresses at the implant/crystal bone interface.
Conclusion: Using rigid framework material with decreasing the tilting of posterior dental implant angulation transmit less stresses to the implant/crystal bone interface.