Do you wince when eating ice cream or does a cup of hot coffee make your teeth ache? If so, then you have sensitive teeth. Cavities and broken teeth can make the teeth sensitive, but if your dentist has ruled those out, your sensitivity may be coming from exposed root surfaces, missing enamel, or cracks.
Roots often become exposed when the gum tissue recedes due to aggressive brushing, periodontal disease, or from clenching or grinding the teeth. Brushing hard at the junction between the tooth and gums can wear away the thin edge of tissue or cause it to retreat away from the tooth. With periodontal disease, as the bone level around the teeth drops so does the gum level, exposing the tooth roots. Grinding your teeth, which often occurs at night during sleep, torques the teeth side to side and often loosens the ligaments that hold the teeth in their sockets, causing the gums to pull away from the tooth.
Enamel makes up the protective outer covering of the teeth. As enamel is worn away, whether through tooth grinding or chemical erosion,the dentin becomes exposed. The dentin layer of the tooth is porous, so when cold, hot, or acidic substances touch this layer, the nerves in the tooth are stimulated. Grinding your teeth can wear away the enamel on the chewing surfaces of the teeth and also can “bend” the tooth at the gumline causing the enamel in this area to chip away. Acid reflux and sucking on lemons are examples of sources of chemicals that can erode the enamel.
Cracks in the teeth can be caused by grinding the teeth, by an improper occlusion or “bad bite,” or by bad habits such as chewing ice. These cracks can lead down into the dentin layer allowing fluid to travel in and out of the tooth, aggravating the cells 
and nerves. Grinding or clenching your teeth puts excessive pressure on the teeth and over time, can cause a fracture in the tooth or can put such pressure on a filling that the tooth cracks. If your teeth don’t fit together properly, chewing can put heavier pressure on areas not designed to withstand such forces. Also, a bad bite can sometimes be the cause of nighttime grinding of the teeth.
and nerves. Grinding or clenching your teeth puts excessive pressure on the teeth and over time, can cause a fracture in the tooth or can put such pressure on a filling that the tooth cracks. If your teeth don’t fit together properly, chewing can put heavier pressure on areas not designed to withstand such forces. Also, a bad bite can sometimes be the cause of nighttime grinding of the teeth.There are many causes of tooth sensitivity. Left unchecked, sometimes the underlying cause can lead to major problems, so notify your dentist of any acute or chronic issues with tooth sensitivity.
