Frontpoint uses different Communication protocols for different devices. They do have an add on Z Wave module which allows some home automation devices through alarm.com , but as far as I know all of the frontpoint branded sensors are using a proprietary frequency which will not work with SmartThings. See the following thread (this is a clickable link)
You can check the FCC label on the sensor itself and look it up, but unless it is using Z wave or zigbee home automation 1.2 (ZHA 1.2), it will not be directly compatible with SmartThings. 
By the way, this type of set up is quite common for security systems. Even the SmartThings/ADT security panel uses a separate frequency for the security sensors.