Biaxial Flexural Strength of Polyetheretherketone PEEK and Composite Structures

Objectives: To assess the bonding between PEEK and Silorane, Ormocer and BisGMA based composites.

Method: 0.5mm thickness discs of PEEK (PEEK OPTIMA, Invibio Ltd, UK) (n=30) were veneered to a thickness of 1.0mm using Ormocer based composite (Voco Admina Ormocer, Cuxhaven, Germany), BisGMA based composite (3M Espe Filtek Z250, St Paul, USA) and a Silorane based composite (3M Espe Filtek Silorane, St Paul, USA). Biaxial Flexural Strength (BFS) testing was carried out with the composite layer upper most (n=15) and again with the composite on the bottom (n=15). The load at failure and  mode of failure was recorded. 1mm thick discs of PEEK, Composite, Ceramic and Zirconia were also tested.

Results:

Arranging the sample with the PEEK material on the bottom resulted in significantly stronger structures in all three PEEK-Composite combinations (P,0.05). The structures produced using BisGMA composite were significantly stronger than those produced using Ormocer which were in turn significantly stronger than the Silorane produced structures (p,0.05). The majority of the fractures observed were within the composite materials alone with 12 of the 90 samples demonstrating fractures through both PEEK and composite. The data can be seen in comparison to other restorative materials as single structure samples.

Conclusion: Ormocer or BisGMA based composite materials show greater strength when than Silorane based composite when bonded to PEEK. This work was supported by Invibio Ltd.