Richard E. Walton DRAINAGE OF AN ABSCESS Irrigation PERlAPlCAL SURGERY Radiographic Verification lndications Flap Replacement and Suturing Anatomic Problems Postoperative Instructions Restorative Considerations Suture Removal and Evaluation Horizontal Root Fracture CORRECTIVE SURGERY Irretrievable Material in Canal Indications Procedural Error Procedural Errors Large Unresolved Lesions After Root Canal Resorptive Perforations Treatment Contraindications Contraindications (or Cautions) Anatomic Considerations Unidentified Cause of Treatment Failure Location of Perforation When Conventional Root Canal Treatment is Accessibility Possible Considerations Simultaneous Root Canal Treatment and Apical Surgical Approach Surgery Repair Material Anatomic Considerations Prognosis Poor Crown and Root Ratio Surgical Procedure Medical (Systemic) Complications HEALING Surgical Procedure RECALL Flap Design ADJUNCTS Semilunar lncision Light and Magnification Devices Submarginal incision Surgical Microscope Full Mucoperiosteal lncision Fiber Optics Anesthesia Guided Tissue Regeneration lncision and Reflection Bone Augmentation Periapical Exposure WHEN TO CONSIDER REFERRAL Curettage Training and Experience Root End Resection Determining the Cause of Root Canal Treatment Root End Preparation and Restoration Failure Root End-Filling Materials Surgical Difficulties Principles of Endodontic Surgery . CHAPTER 17 381 ndodontic surgery is the management or preven- tion of periradicular pathosis by a surgical approach. In general, this includes abscess drainage, periapical Categories of Endodontic Surgery surgery, corrective surgery, intentional replantation, and root removal (Box 17-1). Abscess drainage Surgery has traditionally been an important part of Periapical surgery endodontic treatment. However, until recently there was Hemisection/root amputation little research on indications and contraindications, tech- Intentional replantation niques, success and failure (i.e., long-term prognosis), Corrective surgery wound healing, and materials and devices to augment procedures. Because of this lack of information, many surgeries were performed for the wrong reasons, such as the routine correcting of failed root canal treatment, removing of large lesions believed to be cysts, or the per- forming of single-visit root canal treatment. Indeed, on Indications for Periapical Surgery occasion, a surgical approach is clearly indicated, but few sit- ziations exist in which surgery is required. Other modalities, Anatomic problems preventing coml such as root canal treatment or retreatment, may be pre- dCbridementlobturation ferred. However, when surgery is required, it must adhere Restorative considerations that cornpromlse treatment to basic endodontic principles, that is, the assessing and Horizon,tal root friacture wit h apical necrosis obtaining of adequate dCbridement and obturation of the Irretrieviable mate rial preveliting canal treatment or canal or canals.' retreat ment -.,I -.b-A-.- CI IU,~ :~~IICIIL Root canal treatment is generally a successful proce- Procedulal durinaa trc-*---• dure if the problem is accurately diagnosed and careful Large periapical Ic:sions thait do not r~esolve wit h root technique is used. A common misconception is that if canal treatment conventional root canal treatment fails, surgery is indi- cated for correction. Usually this is not true; most failures are better managed by retreatment.2 At other times sur- gery is necessary to correct a failure or, for other reasons, communicate with the apex. The other suggested may be the only alternative to extraction. approach to manage an abscess in bone is called trephinn- The purpose of this chapter is to present the indica- tion. This is done by attempting to create a pathway with tions and contraindications for endodontic surgery, the a bur or rotary instrument through gingiva and cortical diagnosis and treatment planning, and the basics of bone, directly into the abscess. This approach is of ques- endodontic surgical techniques. Most of the procedures tionable effectiveness." presented should be performed by specialists, or on occa- sion, by experienced generalists. However, the general PERlAPlCAL SURGERY dentist must be skilled in diagnosis and treatment plan- ning and able to recognize which procedures are indicat- Periapical (i.e., periradicular) surgery includes resection of ed in particular situations. When a patient is to be a portion of the root that contains undCbrided or unob- referred to a specialist for treatment, the general dentist turated (or both) canal space. It can also involve reverse must have knowledge sufficient to describe the surgical filling and sealing of the canal when conventional root procedure. In addition, the generalist should assist in the canal treatment is not feasible. It is often performed in follow-up care and long-term assessment of treatment conjunction with apical curettage for reasons explained outcomes. later in this chapter. The procedures discussed in this chapter are drainage of an abscess, apical (i.e., periradicular) surgery, and cor- Indications rective surgery. The success of apical surgery varies considerably, depend- ing on the reason for and nature of the procedure. With DRAINAGE OF AN ABSCESS - - -- - failed root canal treatment, often retreatment is not pos- Drainage releases purulent or hemorrhagic transudates sible or a better result cannot be achieved by a coronal and exudates from a focus of liquefaction necrosis (i.e., approach."f the cause of the failure cannot be identified, abscess). Draining the abscess relieves pain, increases cir- surgical exploration may be necessary (Fig. 17-1). On culation, and removes a potent irritant. The abscess may occasion an unusual entity in the periapical region be confined to bone or may have eroded through bone requires surgical removal and biopsy for identification and periosteum to invade soft tissue. Managing these (Fig. 17-2). Those indications for periapical surgery are intraoral or extraoral swellings by incision for drainage is discussed in the following sections (Box 17-2). reviewed in Chapters 15 and 16. .Irrutortzic ~?rol-)l~rn.$.Calcifications or other block- An abscess in bone may be drained by two methods: ages, severe root curvatures, or constricted canals (i.e., One is by opening into the offending tooth to obtain calcific metamorphosis) may compromise root canal drainage through the canal; the abscess often does not treatment, that is, prevent instrumentation, obturation, 382 PART IV a Itlfections Surglcal exploration A, Perlradlcular leslon on mesial root may be caused by perforation, incomplete debrldement (lateral and aplcal), or vertlcal root fracture. B, Vlsual~zat~onafter flap reflec- tion shows vertical root fracture (arrow); root must be removed or tooth extracted. (Courtesy of Dr 1. Baldassari-Cruz, University of Iowa.) or both (Fig. 17-3). Because a canal is always present (even if very small), failure to debride and obturate may lead to failure. Contraindications (or Cautions) for Pel riapical 5 Although the outcome may be questionable, it is preferable to attempt conventional root canal treatment !I Unidentified cause of root canal treatment failure or retreatment before apical s~rgery.~If this is not possi- Ir When conventional root canal treatment is possible ble, removing or resecting the uninstrumented and rr Combined coronal treatmentlapical surgery unfilled portion of the root and placing a root end filling a When retreatment of a treatment failure is possible may be necessary. n Anatomic structure fjacent nerves and ves- Kc~torutivcc-ottsidcrcztioilc. Root canal treatment may sels) are in jeopard be risky because of problems that may occur from attempt- Structures interfere with access and visibility ing access through; restoration, such as through a crown u Comprornise of crc~wnlroot Iratio on a mandibular incisor. An opening could compromise n Systemic complicaitions (e.g. , bleedin<J disorder: retention of the restoration or perforate the root. Rather b than attempt the root canal treatment, root resection and root-end filling may be referred to seal in irritants. A common requirement for surgery is failed treatment other foreign objects. If evidence of apical pathosis is on a tooth that has been restored with a post and core found, those materials must be removed surgically, usual- (Fig. 17-4). Many posts are difficult to remove or may ly with a portion of the root (Fig. 17-7). cause root fracture during removal. Proceclfrrctl prror. Separated instruments, ledging, Iforizonfal root frt?cturc. Occasionally, after a trau- gross overfills, and perforations (Figs. 17-8 and 17-9 on matic root fracture, the apical segment undergoes pulp pages 388 and 389, respectively) may result in failure. necrosis. Because this cannot be predictably treated from Although overfilling is not in itself an indication for a coronal approach, the apical segment is removed surgi- removal of the material, surgical correction is frequently cally after root canal treatment of the coronal portion necessary in these situations. (Fig. 17-5). Lur~ruttrc~alvcd l~sioi~s ctftcr root ctriicr/ trclut- Irrefriel~uhlcinuteriui irz cctnul. Canals are occasion- rnent. Occasionally, very large periradicular lesions do ally blocked by objects such as separated instruments not heal or may even enlarge after adequate debridement (Fig. 17-6), restorative materials, segments of posts, or and obturation. These are generally best resolved with Prir~ciplrsof Ei~dotlonticS~rr~pery CHAPTER 17