Ceramic biomaterials such as tricalcium phosphate (TCP), hydroxyapatite (HA), zirconia, silicon nitride, and advanced composites like ATZ are widely used in biomedical applications due to their biocompatibility with soft and hard tissues, mechanical strength, and osteoconductivity. Before clinical use, these materials undergo sterilization, which can potentially alter their physical and chemical properties. A systematic understanding of how various sterilization methods influence these ceramics is currently lacking but is critical for ensuring material performance and safety [1,2].
The most common methods are autoclaving (steam sterilization), dry heat, ethylene oxide (EtO), plasma sterilization, and gamma irradiation. Each method has specific advantages and disadvantages regarding temperature exposure, residues, and structural changes.
Gamma sterilization with doses of 25-30 kGy is an effective method for sterilizing ceramic materials, such as β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA). It provides high microbial reduction while showing minimal effects on chemical composition and mechanical strength [3]. Studies have shown that γ-irradiated β-TCP retains its osteoconductivity and compressive strength [4].
On the other hand, autoclaving can lead to grain growth, phase changes, and reduced flexural strength. Phase transformation can be observed in HA ceramics, affecting biocompatibility and resorption rates [5,6].
Ethylene oxide (EtO) is suitable for porous or heat-sensitive materials but can leave toxic residues if ventilation is inadequate [7,8].
Low-temperature processes, such as plasma sterilization, are increasingly being investigated as they are particularly promising for nanostructured or porous ceramics. They enhance the wettability of the surfaces and sterilization can be performed during the surgery [9,10].
The aim of this study is to evaluate and compare the effects of various sterilization methods on commonly used ceramic biomaterials. Specifically, the objective is to identify potential degradation mechanisms or alterations in performance-relevant properties such as mechanical strength, surface characteristics, and structural integrity. By systematically analyzing these changes, the study seeks to derive recommendations for suitable sterilization procedures tailored to each ceramic type, thereby ensuring optimal safety and functionality for biomedical applications.
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