Objective: The objective of this study was to compare changes in the surface morphology and microstructure of different types of 316L orthodontic bracket alloys such as one-piece injection molding (Group A) and two-piece soldering (Group B) that were immersed in artificial saliva solution (37 °C/pH 7.0) for various periods. Methods: An optical microscope, atomic force microscope, X-ray diffractometer, and a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer were used to investigate the surface properties including microstructure, roughness, and chemical compositions. Results: The study results demonstrated that corrosion in both types of orthodontic brackets (A and B) initially occurred in the 3rd month, and an austenite (γ) → [γ + (Fe, Cr)O compound] microstructure transition occurred in the matrix of the bracket body when both orthodontic brackets were subjected to immersion for more than 3 months. Conclusion: The Group A brackets, which exhibited better surface characteristics, maintained a low and constant level of surface roughness after various immersion times. Therefore, a modified metal injection molding (MIM) process based on a thermosetting resin developed with 316L stainless steel showed fewer pores and higher corrosion resistance.
|Number of pages||7|
|Journal||Journal of Experimental and Clinical Medicine(Taiwan)|
|Publication status||Published - 2013|
- Metal bracket
- Metal injection modeling
- Phase transformation
ASJC Scopus subject areas