An in vivo preclinical study assessing biocompatibility of Pd-based bulk metallic glass

Abstract

BACKGROUND: The bulk metallic glass (BMG), Pd79Ag3.5P6Si9.5Ge2, has a high fracture toughness and has been found to accommodate post-yield stress, unlike most other BMG. Moreover, due to its greater noble gas composition it has a intrinsic corrosion resistance, ideal for dental and orthopedic implants. OBJECTIVE: This present study aimed to evaluate the in vivo application of Pd79Ag3.5P6Si9.5Ge2 in a large translational sheep model to assess its efficacy to be utilized as an endosteal device. METHODS: Twelve implants in the form of cylindrical rods (3 mm in diameter) were produced through rapid quenching. Each sheep (n = 12) received one osteotomy in the mandibular region using rotary instrumentation, which was subsequently filled with Pd79Ag3.5P6Si9.5Ge2. After 6- and 24-weeks the animals were euthanized, and samples collected en bloc to conduct histomorphometric analysis. The level/degrees of osseointegration were assessed through bone-to-implant contact (BIC). RESULTS: Favorable BIC was observed with fibrous connective tissue layers at both 6- and 24-weeks. Bone along with interfacial remodeling was observed in proximity with the metallic glass surface at 6 weeks with higher degrees of bone organization being observed at the later healing time, 24 weeks. CONCLUSIONS: The introduced BMG revealed potential to serve as an alternative biomaterial to commonly used Ti alloys given its unique combination of toughness and strength.