The sensitivity and pair carbamide peroxide and hydrogen peroxide kill us attach on bleaching length and bleaching tetracycline stains be sure to check out Dr. Haywood's website. Where you can. View many of the articles that we discussed today and read an entire article that you can on bleaching sensitivity and can you tell us whether theories are behind what causes sensitivity and ways that you can combat it or treat it sure that Seery would do a lot of work in and have been for the last for five years because it's really the only problem with bleaching. Is the with patient sensitivity everything else is manageable works out good no long-term effects everything safe but if they have a history of sensitive teeth off that they apply multiple times during the day they tend to get more to sensitivity we think that sensitivity is just a reversible pole Titus from the insult of the of the peroxide going all the way to the enamel. All with it into the pool and it varies from patient to patient is really not as much product specific as it is patient specific some people just have sensitivity to the number one thing.