Surgical Endodontics and Microsurgery
This domain tests indications, technique and the anatomical structures at risk.
Indications
Failed nonsurgical retreatment, extraradicular infection, unreachable complex anatomy, perforation repair, biopsy of a suspicious lesion, and some root fractures. Contraindications include uncontrolled medical disease, inadequate periodontal support, inability to raise a flap, and an unrestorable tooth.
Presurgical planning
CBCT to assess root position, lesion extent, sinus proximity, mental foramen and inferior alveolar canal. Review anticoagulants, antiresorptives and bleeding history. Photographic and radiographic records for consent.
Flap design
Papilla-base or sulcular full-thickness flaps for most cases; submarginal (Ochsenbein-Luebke) flaps are used where the marginal gingiva must be preserved or where aesthetics permit. Vertical relieving incisions avoid the mental nerve and the neurovascular bundle.
Microsurgical technique
Magnification, microinstruments and ultrasonic retrotips. Resect about 3 mm of root end perpendicular to the long axis to eliminate the majority of apical ramifications, prepare a retrograde cavity along the canal path, and fill with MTA or a bioceramic cement. Hemostasis with ferric sulfate or pressure. Biopsy every surgical specimen. Healing rates around 90% are reported for microsurgery.
Complications
Paresthesia of the inferior alveolar or mental nerve, sinus communication, hemorrhage, flap dehiscence, root fracture, and swallowing or aspiration of small instruments.
Worked example
A maxillary premolar with a persistent lesion after adequate retreatment and a post that cannot be removed. Apical surgery: flap, 3 mm resection, ultrasonic retrograde preparation, MTA fill, sutures, and a biopsy. The post is left undisturbed because the coronal restoration is intact.
Traps
Resecting 1 mm and leaving apical ramifications; beveling the root excessively and exposing tubules; operating without reviewing the canal and sinus anatomy on CBCT.