Tooth sensitivity can also show up when biting down on a specific tooth. You’re eating nuts, let’s say, and suddenly experience sharp pain in a molar. That signals a possible fracture.
Fractures occur most often in teeth with very large fillings. If a filling exceeds one-third the width of a tooth, the integrity of the tooth is compromised. That means the structure of the tooth is weaker—and when you use it to chew something hard, it may crack or a large piece of it may break away.
Once the fracture occurs, the tooth may no longer cause pain. But it will cause sensitivity to hot, cold, sweets, and touch. When that happens, further repair is pointless, and the tooth must either be pulled or protected with an overlay or crown. If the fracture continues below the gumline, the tooth may be hopeless and need to be pulled.
If you have a large filling, prevention is the best solution. Ask your dentist to cover it with an overlay or crown so it won’t crack, and that tooth may well serve you for a lifetime.