Dentist diagnosed my sensitivity to cold first as a receding gum issue. Used a nerve numbing liquid to relax the nerve. $80 out of pocket plus cost covered by insurance. When sensitivity persisted, dentist recommended replacing metal fillings with ceramic fillings. $220 out of pocket plus cost covered by insurance. When sensitivity to cold still persisted 2 weeks later, dentist recommended a crown for the tooth with replaced fillings due to small cracks in the tooth. At this point I got a second opinion, changed tooth brushes and started brushing more gently. No sensitivity issues after 1 week.