Dear Lybrate user, deposition of plaque and calculus on teeth results in yellow/brownish layer. Toothpaste can not remove this hardened layer. You have to visit your dentist for oral prophylaxis/ Scaling procedure and then follow tooth brushing technique recommended by him.
For more info you can contact us through private consultation on Lybrate.
Sensitivity to air etc is seen in some cases after teeth cleaning but it does not mean that the procedure results in any harmful effects on enamel.
Scaling procedure done for teeth cleaning does not effect the tooth structure as it is based on ultrasonic mechanism.
Use Chlorhexidine based non alcoholic mouth rinse twice daily with proper dilution and sensitivity should subside. If it still persists after few days contact your dentist for checkup.
U have to quit tobacco first of all, brush with baking soda and rinse your mouth with lemon water, apply lemon to your teeth, use mouth wash having hydrogen peroxide and visit your dentist you may need scaling.