A novel array chip to monitor in situ composite degradation using electrochemical impedance spectroscopy

Abstract

OBJECTIVES: This paper presents a novel array-chip technology used to monitor the physical properties of dental composites in situ. The DECAY chip (Degradation via Electrochemical Array) leverages microfabrication techniques to construct a uniform array of recessed wells that may be filled with dental restorative materials (e.g. composite or amalgam) and analyzed electrochemically in solution. METHODS: The array enables the uniform preparation of multiple specimens and reference controls on a common substrate, all of which may be simultaneously evaluated. The DECAY-chip presented here consists of a 3x3 array of 100mum deep wells, and is used to monitor the degradation of a common dental composite as a function of time. RESULTS: The data correlate changes in the measured dielectric properties to surface and bulk changes as the composite is exposed to an ethanol:DI mixture (75% ethanol). A model for the system is presented, as are future plans to simplify the methodology for rapid materials screening and in vitro analyses. SIGNIFICANCE: This in situdiagnostic chip will enable evaluation of composite specimens, tested under a wide range of simulated oral environments. It may also serve as a screening platform for new composite formulations and aid in the study of materials degradation and failure mechanisms