There can be several reasons for root sensitivity:

• Brushing habits: heavy brushing, particularly with hard bristle toothbrushes will thin out the enamel in teeth and cause the gums to recede, exposing the softer part of the tooth.
• Tooth grinding: leads to worn teeth leading to more sensitivity.
• Gender: women are more prone to sensitive teeth.
• Age: over time, more of the tooth gets worn away, leading to sensitivity.
• Diet: acidic substances cause erosion of enamel and dentin in teeth, opening the dentinal tubules responsible for sensitivity. Citrus, acidic beverages (including soda) are harmful for people with already sensitive teeth. Brushing immediately after ingesting these beverages may compound the situation.
• Smokeless tobacco: when placed between the gum and cheek caused recession, exposing the softer parts of the tooth, namely the root. Brushing on this part of the tooth erodes the tooth faster and causes increased sensitivity.
• Disease: Bulimia or GERD predispose people to increased sensitivity in their teeth due to increased acid in the mouth. Periodontal or gum disease also increases root exposure and leads to more sensitivity in teeth.

Treatment for sensitive teeth is based on the diagnosis as to what is causing the sensitivity. It can be as simple as an over the counter toothpaste like Sensodyne.