<s>[INST] Hi, my name is muktar, i have never been to a dentist for my teeth to be check, it over 29 years now. the truth is i have never had reason to do so but i notice that when i brushing the back of my upper teeth (incisor) i have this shocking feeling i just want to run it through you guys first thank you. [/INST] Since you have have shocking feeling....it may be sensitivity which u can not able to explain... it's been 29 yrs you haven't visited dentist....perhaps there is a large amount of calculus in the interdental area between the teeth... so I would suggest you do visit ur nearby dentist and get your oral checkup done along with the cleaning of teeth..Hope this will help you. . </s>