Healing of Apical Lesions: How Do They Heal, Why Does the Healing Take So Long, and Why Do Some Lesions Fail to Heal?

Apical lesions are radiolucent lesions that appear in the bone surrounding portals of exit from infected root canal systems. Many but not all apical lesions will heal in response to adequate debridement, disinfection, and obturation of the root canal. Such healing may be a prolonged process, and some lesions will fail to heal. To understand why the healing process is often prolonged and why some lesions fail to heal, the nature of these lesions and the processes leading to their development must be understood. Some apical lesions fail to respond to intracanal endodontic treatment. However, many of them will heal after subsequent apical surgery has been applied. The reasons for such failures are discussed in this chapter to understand why apical surgery does lead to healing in many cases that originally failed to heal.