Tooth decay can occur if you do not maintain good oral hygiene and allow plaque and germs to accumulate behind a dental crown. The biggest issue comes at the crown's edge, where it meets the gum line, as this area is prone to deterioration. Although the crown is resistant to decay, the underlying tooth absorbs plaque and germs.
As a result, decay can spread swiftly beneath the crown. In extreme cases of decline, the tooth structure under the crown may be unable to shield the pulp from injury. In many cases, merely replacing the crown does not address the problem. Root canal treatment and a new crown are required to salvage the tooth.