While a rebuild or service shouldn't be necessary for an extended period of time after purchase, should you notice your stem develop lateral play, a service or a rebuild could be a good idea. Service kits are available through the website if/when a rebuild is in order.  

Best practice to keep your stem running smoothly is to rinse and wash on a regular basis with a mild soap. Occasionally check the torque of the 4mm clamp bolts on the steerer tube mount and faceplate. Additionally, the pivot axle can be periodically lubricated with a light oil.