Sometimes teeth can develop cracks, and when not treated this can have serious consequences for your oral health. Cracks can come from injury or large fillings that weaken the rest of the tooth. Even small cracks can allow bacteria into the tooth causing decay or infection, leading to further destruction. A cracked tooth may or may not be sensitive to hot and cold or be painful when biting or chewing. Cracks that progress too far can result in entire sections of the tooth breaking off, and in some cases loss of the tooth entirely.