Finite Element Analysis of Monolithic PEEK and Zirconia Fixed Dental Prosthesis (In vitro Study)

Background: Difference in the elastic modulus between zirconia and dentin may cause unfavorable stresses on dental abutments. A high performance polymer has been recently introduced with similar elastic modulus in attempts to enhance stress distribution. Aim of the study: To compare the stress distribution, on abutment teeth, of CAD/CAM milled PEEK to Zirconia Fixed Dental Prosthesis Materials and methods: Two three unit bridges were fabricated to replace a lower 2nd premolar on a stainless steel master model. A finite element analysis was done by 3D modeling of the two fixed dental prosthesis. Eight FDP models were simulated models and divided into two equal (n=4) according to the type of material used: Group Zr, monolithic zirconia and Group P, monolithic ceramic reinforced PEEK. The simulated models received a compressive load of 100N and an oblique load of 50 N at the pontic. The resultant stress ratios and deformations were analyzed by using ANSYS ®. Results: PEEK showed high von misses stresses and total deformation in the cement layer. Both restoration materials showed extreme stress values at the dentin interface under oblique loading. Conclusions: From a biomechanical perspective, PEEK transfer more stresses to the underlying cement layer. Under oblique loading, PEEK is generally safer to the underlying dentin than zirconia. Clinical implications: According to the current study, both materials can withstand chewing forces in the posterior region. However, PEEK restorations showed enhanced stress transfer which could lead to a shorter lifetime for the underlying cement.