Since I do not know the specifics of the workpieces and cutting tools I can not give possible specific answers. I will attempt to give some more general answers.
1.) Yes, dull cutters can cause excessive burrs.
2.) The material being cut. Cast iron=nearly zero burrs, chipping may be more of a problem. Steel could result in serious burrs.
3.) Cut direction may cause excessive burrs. Climb cutting moves the burr to the bottom. This refers to gear hobbing.
4.) If gears can be stacked, only one side of a stacked pair will have the larger burrs.
5.) Most gear hobbing machines can be equipped with a deburring attachment (scraper blade) to remove burrs as they are being created.
6.) A 2-cut cycle can be employed to improve gear accuracy (quality, finish etc.) and reduce burrs.
7.) When sharpening hobs, great care must taken to retain the original geometry ground into the cutting face of the teeth. For example, if the original face was ground with a neutral angle then reground to a positive angle, the tooth profile will change. If the original helix angle was 7 degrees and is reground to some other angle, the tooth profile will also change. Totally unacceptable for automotive transmissions. Probably will cause noisy transmissions.
Hope that helps.