Even after a tooth has been restored, sometimes decay can reappear and compromise the structure of the tooth all over again. Unfortunately, in these cases the same process that created decay in the first place can create it again. Bacteria works its way into the areas of the tooth surrounding and supporting the filling, and the tooth begins to deteriorate as a result. As the decay worsens, the tooth continues to weaken, which can result in cracking, pain and potentially tooth breakage or loss. If caught early enough, the decay can typically be removed, and the tooth refilled or crowned. However, if left unaddressed, more serious procedures might be needed, such as a root canal, bridge or a dental implant.