Surgeons · Materials
Printed titanium, PEEK, PMMA: a technical comparison in figures
No material has proven superior in cranioplasty. Yet each has measurable properties that guide the choice according to the defect, the patient and the expected follow-up. Here they are side by side, with sources.
3 min read11 sources
Mechanical properties
| Property | Ti-6Al-4V ELI titanium | PEEK | PMMA (cement) |
|---|---|---|---|
| Elastic modulus | ≈ 110 GPa | 3 to 4 GPa | ≥ 1.8 GPa in bending |
| Strength | ≥ 860 MPa in tension | Lower than titanium | ≥ 70 MPa in compression, ≥ 50 MPa in bending |
| Density | 4.43 g/cm³ | ≈ 1.3 g/cm³ | ≈ 1.2 g/cm³ |
| Bond to bone | Possible depending on the surface | None | None |
Titanium: minima of the ASTM F136 standard and typical values [1]. PEEK: after Kurtz and Devine [2]. PMMA: minima of the ISO 5833 standard for acrylic cements [3]. Cortical bone: 18.6 to 20.7 GPa depending on the measurement method [4].
The elastic modulus measures stiffness: titanium is about five times stiffer than cortical bone, PEEK about five times more flexible. In an implant, geometry matters as much as material: thickness, curvature and perforations set the stiffness of the part.
Thickness, weight and shape
The strength of titanium allows thin parts: in the three cranioplasties shown on this site, the median thickness ranges from 2.1 to 2.9 mm for 125 to 156 g, and drops to 0.45 mm for an orbital floor. PEEK implants are thicker for comparable strength.
3D printing of titanium allows shapes that cannot be machined: built-in fixation tabs, perforations for drainage and tissue adhesion, complex curvature transitions. Custom PEEK is most often milled; PMMA is moulded, in theatre or in advance.
PMMA shaped in theatre
PMMA gives off heat as it polymerises. In a cadaver simulation, tissue next to the cement was exposed to more than 50 °C for prolonged periods, and the temperature rose with thickness; the authors recommend prostheses made before surgery [5].
3D-printed moulds make it possible to cast PMMA in advance at very low cost: about $40 per implant for a team in Pakistan [6].
Infections and complications
Published rates vary widely from one series to another: follow-up lengths, definitions and populations differ, so materials cannot be ranked on this basis. In the absence of a head-to-head trial, the international consensus considers that the best material remains to be determined [8].
Two findings stand out nonetheless. PMMA is among the materials most prone to infection: 14.9% in a review of 3,260 custom implants [7]. And whatever the implant, thin or scarred covering skin carries a risk of exposure: the state of the tissue matters as much as the material.
Imaging and cost
On CT, titanium causes only limited artefacts. On MRI, they are more marked at 3 tesla than at 1.5 tesla and shrink markedly with suitable sequences [9].
On price, a custom PEEK cranial implant has been reimbursed at €5,275 in France since July 2026 [10]. In the United States, a team reported $12,600 for a PEEK implant, against $6,750 for flat titanium mesh to be shaped in theatre [11].
The choice of material rests with the surgeon. IME TECH makes titanium implants; this comparison relies on published sources.
Sources
Documents accessed in October 2026. Amounts are given in the currency and for the year of each source.
- 1ASTM F136. Standard specification for wrought titanium-6aluminum-4vanadium ELI (extra low interstitial) alloy for surgical implant applications (UNS R56401). dinmedia.de
- 2Kurtz SM, Devine JN. PEEK biomaterials in trauma, orthopedic, and spinal implants. Biomaterials. 2007;28(32):4845-4869. doi.org
- 3ISO 5833:2002. Implants for surgery — Acrylic resin cements. iso.org
- 4Rho JY, Ashman RB, Turner CH. Young’s modulus of trabecular and cortical bone material: ultrasonic and microtensile measurements. J Biomech. 1993;26(2):111-119. doi.org
- 5Golz T, Graham CR, Busch LC, Wulf J, Winder RJ. Temperature elevation during simulated polymethylmethacrylate (PMMA) cranioplasty in a cadaver model. J Clin Neurosci. 2010;17(5):617-622. doi.org
- 6Ashraf M, Choudhary N, Kamboh UA, et al. Early experience with patient-specific low-cost 3D-printed polymethylmethacrylate cranioplasty implants in a lower-middle-income-country: technical note and economic analysis. Surg Neurol Int. 2022;13:270. doi.org
- 7Faedo F, Zaed I, Pizzi A, Iaccarino C, Servadei F. Infection rates following custom-made cranioplasty using heterologous materials: insights from a systematic review on 3260 patients with a focus on follow-up length. Neurosurg Rev. 2025;48:657. doi.org
- 8Iaccarino C, Kolias A, et al. Consensus statement from the international consensus meeting on post-traumatic cranioplasty. Acta Neurochir (Wien). 2021;163(2):423-440. doi.org
- 9Ondrejová B, Rajťúková V, Šavrtková K, et al. Analysis of MRI artifacts induced by cranial implants in phantom models. Healthcare (Basel). 2025;13(7):803. doi.org
- 10Avis relatif à la tarification du substitut osseux sur mesure pour reconstruction crânienne PEEK. Journal officiel de la République française n° 0180, 5 août 2025. legifrance.gouv.fr
- 11Kinsman M, Aljuboori Z, Ball T, Nauta H, Boakye M. Rapid high-fidelity contour shaping of titanium mesh implants for cranioplasty defects using patient-specific molds created with low-cost 3D printing: a case series. Surg Neurol Int. 2020;11:288. doi.org
General information: this article does not replace your surgeon’s advice. Prices vary with the patient, the hospital and the implant; only a formal quote is binding.
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