Effects of nanoparticles on the mechanical and physical properties of maxillofacial silicones: A literature review

Background: Since the 1960s, silicone has been the material of choice for maxillofacial prostheses due to its biocompatibility and favorable mechanical properties. However, reduced strength, color instability, and susceptibility to ultraviolet and oxygen degradation limit its longevity. Nanoparticles such as titanium dioxide (TiO 2 ), zinc oxide (ZnO), SiO 2 , and ZrO 2 , have been introduced to enhance silicone’s resistance to environmental stress, abrasion, and photodegradation. Materials and Methods: This systematic review assessed the influence of nanoparticles on the properties of maxillofacial silicones. A literature search was conducted in PubMed, Scopus, Web of Science, Cochrane, and Google Scholar. Eligible studies included systematic reviews and meta-analyses published in the past decade, focusing on the effect of nanoparticles on the mechanical and physical performance of silicones. Data were analyzed according to nanoparticle type and reported outcomes. Results: Six categories of nanoparticles were identified across the reviewed studies. The most frequently examined were TiO 2 , ZnO, SiO 2 , and ZrO 2 , while others included ZrSiO 4 , TiSiO 4 , Ag-Zn Zeolite, and Al 2 O 3 . Findings demonstrated improvements in tensile strength, hardness, flexibility, compressive resistance, and color stability. Nanoparticles also enhanced resistance to aging and environmental changes, while some (e.g., Ag-Zn Zeolite) provided antimicrobial effects. Conclusion: Incorporating nanoparticles into maxillofacial silicones considerably enhances their mechanical, physical, and biological properties.