Natural mollusk shells as a potential dental material

Abstract

The mollusk shells in Nature have evolved ingenious architectures and achieved outstanding mechanical properties, thereby demonstrating a potential for tissue engineering applications; nevertheless, despite a broad investigation of them for gaining inspiration towards guiding the design of man-made materials, the mollusk shells have rarely been explored for directly using as a biomedical material. This study offers a preliminary evaluation about the potential and feasibility of natural mollusk shells for using as dental replacements by systematically examining their aesthetic performance, machinability, as well as mechanical and biological properties. The shells exhibit a variety of colors with natural lusters, and can be processed into desired shapes and dimensions with good surface finish. The Strombus latissimus shell has a comparable flexural strength as human teeth, and exhibits higher fracture toughness than most of commercial dental materials along with stable crack extension featured by rising R-curve behavior owing to the effective toughening effects of crossed-lamellar architecture. Additionally, the shell displays a good cytocompatibility and certain antifungal function because of its hydrophilic and negative charged surfaces with low roughness. A simple and viable approach was further exploited for enhancing the hardness of natural mollusk shells by immersing them in aqueous solutions of metal ions. The unique combination of properties makes the natural mollusk shells promising for dental applications which may represent a potentially new protocol for tissue engineering.