Crest pro-health or scope whitening mouthwash, which is better?

Ask your hygienist: Mouth rinse choices are very subjective and highly consumer market driven. While neither of these are near the top of my list, consider hygiene in general: assuming you floss ; use a tongue scraper daily, see your dentist regularly ; have impeccable oral hygiene to start, mouth rinse may help improve things a step further; find one that serves your specific goal, pick your favorite flavor ;-).

Mouth Rinses: I prefer listerine (the purple color) but thats just my preference. Most of the popular multi-purpose rinses and tooth pastes do the same thing, but they are adjuncts as there is no substitute for thorough daily homecare. Brushing, flossing (and/or water picking), scraping or brushing the tongue, and full strength mouth rinse sounds like a complete regimen for success.