The MOBEX was conducted to rehearse this operation procedure. Commander Song Hwan Yun, 32nd KSC Company, KSC, said, Although these are annual exercises and we perform them every year, the exercises this year, especially the MOBEX, were executed with a contingency or wartime situation in mind.
It is very unfortunate when there are black rims around porcelain crowns and porcelain veneers. This should NOT happen! The black stain around the rim of the crown or porcelain veneers is contamination. The bonding technique was a failure as there was something that was not completed thoroughly. In all fairness to the dentist, it is very difficult to bond porcelain crowns and porcelain veneers at the gum line.
The part of the tooth that you can see is called the crown. The outer part of it is covered with a hard white material called enamel which protects the tooth. It is often hard and shiny and acts as a tooth's bodyguard. It protects the inside parts of the tooth. Below it is dentin, a yellow bonelike material that is softer than the outer part.