Evaluation of structural and mechanical properties of aerosol-deposited bioceramic films for orthodontic brackets

Four types of bioceramic films (Al2O3, SiO2, hydroxyapatite (HA), and brushite) were prepared via a simple aerosol deposition (AD) process at room temperature, and their structural and mechanical characteristics were compared to verify their potential for use in orthodontic brackets. The results showed that the HA and brushite films featured considerably high deposition rates compared with other coating technologies. Moreover, it was revealed that the crystallite size of all samples was largely reduced below 100 nm, which can enhance the biological performance and mechanical properties of bioceramic films. The HA and brushite films also had optimum mechanical properties, namely, adhesive strength and shear bond strength. These two instrumental mechanical properties were believed to be achieved by not only thicker bumps due to the high deposition rate but also strong mechanical interlocking at the ceramic-to-resin interface. This study confirmed that AD-prepared HA and brushite films have high potential for application in orthodontic brackets.