Harsh brushing of teeth can cause abrasion cavities that appears concaved near the region of the gums and this can make your teeth feel sensitive to substances that are hot and cold.  With this bad dental situation, it is best that you get yourself checked by a dental expert and get that cavity filled up by a dentist and be learned about the proper brushing technique.  To help avoid receding gum problems, try to use a soft toothbrush then try to brush teeth with gentle massaging pressure.  Periodontitis is another common reason why gum recession happens by which there is actually loss of bones which supports the teeth. This condition call for a natural and right treatments that can help arrest the disease and prevent further progression.