Tooth decay can reappear even after it was restored to its optimal health. Over the course of time, bacteria buildup can reach into areas that surround and support the filing. As a result, tooth starts deteriorating. As the decay continues, tooth continues to become weaker. This can lead to cracking, tooth breakage, or even loss of it. If detected early, the decay can be controlled and tooth can be crowned or re-filled. However, leaving the condition untreated can later demand more elaborate procedures such as dental implants, bridges, or root canal.