You'll need it drafted if it is to print.  Teeth will be difficult if it's particularly small depending on the resolution of the printer.  You may need something specialized to handle small parts.  Something with 1/16th stepping enabled, and with a much smaller diameter print nozzle.  There are generally two different plastic types to work with.  You'll probably want ABS, but it will be difficult to shape the gear out of it depending on how small it is.

So, the parameters are thus:  Ensure a heat-bed is used, add some cooling (but not too much) for the gear teeth, make sure that the highest resolution possible is used (a stepper-motor driver capable of 1/16th microsteps) as well as a small print nozzle.  But drafting the part will be the most difficult.