3D-Printed Polyether Ether Ketone (PEEK) for Biohybrid Root-Analogue Dental Implants
Nesma El-Amier,F aculty of Oral Medicine and Oral Health Sciences,聽UU直播, Raphael de Souza, Associate Professor, University: UU直播.
Background: Tooth loss has a devastating impact on the quality of life due to impaired oral functions combined with aesthetic disfigurement. The periodontal ligament (PDL) that surrounds natural teeth is adaptive to diverse biomechanical challenges. PDL deforms to dissipate strains over a larger area through natural dental roots. In contrast, current osseointegrated dental implants with their screw design transfer intense concentrated forces to peri-implant bone and thus undergo possible biomechanical failures. Moreover, there is a mismatch in elastic modulus between titanium alloys (the gold standard for dental implant fabrication) and human bone that leads to stress shielding effect and eventual implant loss. An alternative is polyether-ether-ketone (PEEK), which is a biocompatible implant fabrication material with an elastic modulus closer to human bone, thus optimizing stress distribution. PEEK-implants can be customized by fuseddeposition-modeling (FDM) 3D-printing technology. Currently, a dental implant with both (PDL and natural root morphology) does not exist, and it is unknown whether mimicking natural root morphology with a PDL-like layer in PEEK-implants could restore the adaptive and biomechanical functions of natural teeth. Objectives: The overarching goal is to develop a root-analogue dental implant with improve biomechanical and adaptive functions using FDM-printed PEEK. In this first phase, the ability of FDM-printed PEEK to precisely reproduce the root morphology and the biomechanical behaviour of natural teeth will be studied by varying the 3D-printing parameters.
Methodology: The FDM-printing parameters of PEEK will be optimized to reproduce the mechanical characteristics of dentine and jaw bone by testing different combinations of FDMprinting variables among PEEK samples including: nozzle diameter, nozzle temperature, layer thickness, raster angle and printing speed. Computed tomograms will be used to 3D-print PEEK implants with patient-specific root morphology, which will be tested for their trueness and precision. Finite element analysis (FEA) will be used to compare stress/strain transfer to surrounding alveolar bone through single and multi-rooted analogue PEEK implants (with and without PDL space) in comparison to natural dentition. Expected results: Experiments will be performed with a sample size n=10 for each tested group.
One-way ANOVA with Tukey鈥檚 HSD test, or Kruskal-Wallis test (depending on homoscedasticity and normality) will be conducted using SPSS 22.0 to determine the statistical significance (p<0.05) among samples.We hypothesize that 3D printing parameters of PEEK can be tuned to accurately print single and multi-rooted implants with biomechanical behaviour similar to natural dentition. Research impact: Our study collaborates with Dr. Cerruti鈥檚 lab that has expertise in periodontal tissue formation around PEEK implants through collagen grafting and surface engineering. We expect that this collaboration will help development of root-analogue implants that restore the biomechanical functions of natural roots and periodontal tissues, thus enhancing implant function and lifetime while promoting surrounding bone health. Hence, these novel bio-implants will improve the oral health and quality of life for patients suffering tooth loss worldwide.
Keywords: Patient-specific implants (PSIs); Polyether ether ketone (PEEK); 3D Printing; Fused deposition modeling (FDM); Finite Element Analysis (FEA); Periodontal ligament (PDL).