This filling has lost its seal and no longer fully protects the tooth from cavities. When they’re small like this, it’s easy to replace them with new plastic fillings.
But sometimes, front fillings fail in another way. There’s a tremendous amount of force on the edges of teeth when you bite together. As you can see here, some of the tooth broke away from the biting edge as a result of biting pressure.
To strengthen the tooth and protect it from future damage, crowning or bonding may be necessary.