“Corrective surgery is managing defects that have occurred by a biologic response (Le., resorption or iatrogenic (i.e., procedural) error, These may be anywhere on the root, from cervical margin to apex. Many are accessible; others are difficult to reach or are in virtually inaccessible areas. Usually, an injury or defect has occurred on the root. In response to the injury, there may be an inflammatorylesion or one may develop in the future. A corrective procedure is necessary. Generally, the procedure involves exposing, preparing, then sealing the defect, Usually included are removal of irritants and rebuilding the root surface (Box 17-4.
Procedural errors. Procedural errors are openings through the lateral root surface created by the ope-rator, typically during access, canal Instrumentation, or _post space preparation (Fig. 17-25). i’he result is perforation, whlch presents a difficult surgical challenge, more so.
than repairing damage to a root end. Perforations often require restorative management and completion of the root canal treatment, usually in conjunction with the surgical phase. The location of the perforation influences success; some arc virtually inaccessible. If the defect is on the interproximal, in the furcation, or close to adjacent teeth or to the lingual, adequate repair may not be possible or is compromised. Defects that are too far posterior (particularly on the distal or lingual aspects) may be very difficult to reach. The nature and location of the perforation should be determined with angled radiographs before the decision is made; whether to
repair surgically, to remove the involved root, or to cxtract.
Anatoni consideration. Consideration must be given to structural impediments to a surgical approach. Few exist. and must can be managed or avoided. Included are various nerve and vessel bundles and bony structures, such as the external oblique ridge. Locution . As mentioned previously the defect must be accessible surgically. This means the clinician he able to locate and, ideally, to readily visualize till’ ‘urgical area handpiece or an ultrasonic instrument generally is necessary to prepare the defect. Therefore the defect m st be reachable, without impedance by .structures or hyack of visibility.
Surgrical approach. Repair presents a unique set of problems. The defect may wrap from facial to proxlrr-al to lingual, creating not only difficulties in visualizatlon hut also problems with access and hemostasis and material
placement. A general SlIi,lvline h that the detect h larger and more complex appears on a radiograph.
FIG. 17-24 Special small amalgam carriers are used to place material, which is then packed with. small condensers. Other cement type of materials are carried and compacted with ‘paddles and burnishers.
A. Frontal view. 8, Cross-section.
Prognosis, Repairs in the cervical third or furcation in particular have the poorest prognosis. Communication often is eventually established with the junctional epithelium, which will result in periodontal breakdown, loss of
attachment, and pocket formation. This would mean that a periodontal procedure (e.g., crown lengthening) would be required in conjunction with the defect repair.
After the basic. approaches with periapical surgery, the next step is to perform corrective surgery. Flap d~igns are similar but are more limlted.A sulcular incision is usually .required, with at least one vertical incision to form a threecornered flap. A full-thickness flap is reflected and bone removed to expose the defect (Fig. 17-27). Bone removal must-be .adequate to allow maximal visualization and access.IfPossible,a rim of cervical bone should be retained to support the flap and possibly to enhance reattachment; this is frequently not possible with cervical defects.
The facial or lingual cavity is then filled by direct placement of the material. Aclass II (l.e., interproximal, or ‘furcation) cavity requires a matrix. For example, an amalgam matrix band is held in position with fingers or a wedge, then material is packed into the cavity preparation. This matrix is less critical if amalgam is not used. The material is carved flush with the cavity margins. Flap replacement, suturing, and digital pressure are as described earl. Suture removal should be within 3 to (days Postoperative instructions are similar to those after periapical surgery.