Teeth cleaning is done by ultrasonic vibratory scalers. They just vibrate on surface of teeth. They cannot cut or damage teeth. If the blackness is due to stains, calculus or tartar then scaling will remove it. If it is due to decay then restoration needs to be done.
Next Steps
Visit dentist for clinical examination.
Health Tips
"Does Teeth Cleaning Damage Teeth?" by Dr.Rashmi Bamane - https://www.practo.com/healthfeed/does-teeth-cleaning-damage-teeth-39823/post