Teeth bonding is a technique that etches the teeth so that restorative materials will more easily adhere. Often, bonding involves molding material directly onto your tooth so it can be used to rebuild part of the tooth or to attach other materials, such as porcelain veneers. Bonding is used to replace old fillings, close gaps or repair chipped teeth. It can be used to mask a stubborn stain or to attach other restorations.