Microdermabrasion vs chemical peels for dark/ethnic skin?

Microdermabrasion are beneficial for all types of skin. Microdermabrasion treatments are to exfoliate your skin and help with your skin texture overall. Peels in the other hand are more intense but it can vary individually. I would recommend you have a consult with your Dermatologist to see what percentage for the Peel the Clinician can start you with. 
Best,
Dr. Alex Khadavi MD 

Good afternoon and thank you for your question! Microdermabrasion will not do anything for scarring. In addition, unless you have a deep chemical peel performed by a physician it most likely will not help scarring either. I recommend getting a formal evaluation by a board-certified plastic surgeon to decide on the best treatment for your skin type. Microneedling or microneedling with radio-frequency (i.e. Fractora) can help in reducing the appearance of scarring and fine lines. Any treatment designed to help scarring will most likely take a series of sessions. Best of luck! For information, please feel free to visit our website!

Any procedure that produces inflammation can produce increased pigment in black skin.  it is difficult to tell you what to do without seeing you for an evaluation of your problem and your skin color.  see a board certified dermatologist