Horses require regular dental care, just like humans. Because of the way domestic horses are fed, they need annual, or sometimes semi-annual, checkups and floats by veterinarians or equine dentists. Floating prevents sharp points from forming on the edges of their teeth.
Source: The Paulick Report, March 28, 2016
Horses get sharp points or unevenness on their teeth when their teeth grind together as they chew.