<s>[INST] hi, i want to ask out of so many desensitizing toothpastes available of different brands and withing the same brands. on what basis should we choose?eg out of sensodent,sensodent K,sensoform and sensodent KF? Can such tooth pastes can be used over a prolonged period of time? [/INST] Hello,Choosing a desensitizing tooth paste depend on your degree of tooth wearing and the amount of sensitivity. You should start with a very basic one like plain sensodent , apply for 10-15 minutes, do it for two times daily for at least 1 week. If you did not  feel relief from that then you should visit your dentist as he will examine the tooth and then prescribe you what is needed, as without proper examination just experimenting with anything is not done.Hope it will help youThank you </s>