Dominican plugs are the same as most found in the USA, and so is the type of current (110 Volts/60 HZ), so only Europeans will need a converter.
Most electronic devices now operate in the 110V till 240V range, making an adaptor often all that is needed. You can buy these adaptors locally and they will fit the common European systems.
Voltage irregularities are common; always protect your costly devices against surges.