Figure 2. AISI 304 stainless steel brackets’ cytotoxic-corrosion extracts. L929 cells cultured (3.5 x 10⁴ cells/100 µL of medium) to obtain a cell monolayer. After 24 hrs (37°C, 5% CO₂), 20 µL of control saliva, low-nickel steel or AISI 304 stainless steel-bracket extracts, obtained after 42 days of incubation, were added to the culture separately. After a 48-hour exposure period (37°C, 5% CO₂), crystal violet (A) and MTT (B) assays were performed as described in MATERIALS & METHODS. Data represent mean ± SEM (n = 6). *p < 0.05.