Slight sensation when brushing or scratching the tooth. Reactive to cold.
You may be suffering dentine hypersensitivity, caused from loss of enamel. Dental enamel is the very hard protective coating covering each tooth. It is formed in early childhood and does not replenish over a lifetime. Once the tooth has lost enamel, it is gone for good. Teeth can lose enamel from grinding (including brushing too vigorously), bacterial attack (dental decay), acid erosion (from acidic fluids like lemons, cola’s and stomach acids), and from receding gums.