Jewelry worn in pierced tongues can lead to painful tooth microfractures, says one dental expert. The repetitive tapping can cause microfractures -- tiny hairline fractures in tooth enamel that remain invisible to the naked eye. These microscopic cracks can leave the nerve of the tooth exposed to either temperature changes or small food particles, causing mild to severe pain. The typical tongue-jewelry induced microfracture sufferer complains of pain but looks healthy and has no cavities. Most jewelry-induced microfractures occur in the pre-molar teeth. It is difficult to get tongue pierced patients to stop their 'tapping' habit. People develop repetitive habits to relieve stress, and asking a patient to stop tapping their tongue ring can be like taking a security blanket from a child.