I had gone to the dentist for a filling on my left side due to some slight discomfort. The dentist noticed a second cavity on the right side. He filled both that day. He said the one on the left seemed small at the beginning but went pretty far into the tooth. (He had been hoping to not have to numb me completely.) The left one hadn't even been a bother for me yet. Since then I have had stabbing, sharp pains shoot through my tooth while eating (soft foods nothing hard) or if I create suction by the tooth.