Caracterização química e metalográfica dos aços inoxidáveis de implantes removidos de pacientes

OBJECTIVE: This study examines the chemical and metallographic composition (microstructure, grain size, inclusion content) of austenitic stainless steel developed as biomaterials for used in the manufacture of orthopedic implants. METHOD: An analysis was carried out of twelve implants removed from patients affected by inflammation. Chemical analyses were carried out using Optical Emission Spectrometry and Energy Dispersive Microanalysis (EDS), and the grain size was determined by optical microscopy and scanning electron microscopy (SEM) according to ASTM Standard E 1382 97. RESULTS: It was observed that all the implants had a larger grain size than is recommended by the Standard. The presence of delta ferrite was also observed in ten of the twelve implants removed, which according to ASTM Standard F138-92, should not be perceived microscopically under magnification of 100x. CONCLUSIONS: In eight cases, there is a strong indication that the inflammation was triggered by pitting corrosion. Level of Evidence: Level III, Systematic review of studies.