Microsurgeries in endodontic treatment are surgical procedures performed under magnification following failure of a non-surgical root canal, also known simply as a root canal. Root canal treatment can fail for many reasons. In order to decide whether surgery is the proper treatment approach, it is important to establish the etiology of the disease.
Bacteria from the oral cavity enters the root canal system following a carious or traumatic insult to the tooth. This bacteria is then able to produce inflammation and subsequent gradual necrosis of pulpal tissue. As bacteria continues to degrade pulpal tissue, it is possible for bacteria to exit the root canal system through the apex of the tooth and cause destruction of supporting bone. The success of a nonsurgical root canal is achieved by the elimination of the effects of disease-causing bacteria within the canal system. Upon exit of bacteria through the apex of the tooth, it becomes substantially more difficult to eliminate the effects of these bacteria with traditional root canal therapy. In these cases, endodontic microsurgery presents a viable option to addressing bacterial activity on the outside of the tooth.
Nonsurgical root canal therapy is recommended in a variety of situations where the pulpal tissue has been irreversibly affected. Such damage frequently results in dental pain or non-painful sequelae within the surrounding bone. Sequence of treatment for teeth that have not been previously endodontically treated typically includes non-surgical root canal therapy followed by close monitoring and evaluation for the dissolution of associated symptoms and pathology. For teeth that have been previously endodontically treated, nonsurgical retreatment of the tooth should first be attempted in an effort to improve upon the cleaning and shaping initiated with the first root canal procedure.
Following the retreat, another period of monitoring is allowed to assess whether elimination of bacteria within the canal system allows healing. If the pathology or symptoms are not resolved, it is at this time that surgical intervention may become an option to eliminate the disease process.
Surgical options available beyond nonsurgical root canal therapy include apicoectomies and intentional replantation, often provided by endodontic specialists. Apicoectomies are performed through a carefully prepared osteotomy through buccal bone with the goal of visualizing the apex of the tooth to be treated. With adequate visibility, the end of the root is ideally resected by a measurement of 3 mm. Following resection, the root end is then prepared with ultrasonic instruments and retrofilled with a biocompatible putty material.
Intentional replant cases are similar in purpose but are essentially an apicoectomy performed extraorally. Ideal cases for intentional replantation are teeth with unresolved symptomatic periapical pathology associated with teeth distal to the first molar position. Additionally, teeth that present as ideal cases are those with conical root anatomy that can be atraumatically extracted. This procedure is time sensitive and should take place inside of 15 minutes of the tooth being out of the mouth.
In this time, the root is resected by a minimum of 3 mm, stained with methylene blue and evaluated for cracks, and retroprepped and filled. After replacement in the mouth, firm pressure is required to support acceptance of the tooth back into the periodontium.
Endodontic therapy provides an opportunity for patients to retain their natural teeth following carious or traumatic insults. When counseling patients about available treatment, it is important to present all options so that they can be properly educated to make the decision best for them.
~Francesca Daigle, Texas A&M ‘21