Complications in Endodontic Surgery

A modern surgical endodontic treatment is a predictable and efficient procedure. Like any treatment modality, surgical endodontics is exposed to risk of complications. Possible complications should be considered in the decision making process, so they could be anticipated, prevented, diagnosed or managed correctly. Both patient and practitioner related matters, that might affect the risk of complications and the ability to manage those complications in case they occur, need to be recognized.

The application of an evidence-based approach for prevention, identification and management of surgical complications should result in a reduction of mistakes in the clinical decision making process.

Diagnosis is the art and science of detecting and distinguishing deviations from health and the cause and nature thereof and should be the foundation for clinical decision making.

Adequate diagnosis is based on sound knowledge and efficient clinical reasoning. Errors during the clinical reasoning process may ultimately lead to misdiagnosis and ensuing complications. This chapter will review misdiagnosis complications in teeth scheduled for endodontic surgery.

The first part of this chapter is concerning cases of exploratory surgery. The section about alleviation of symptoms of apical periodontitis focuses on drainage. Indications for endodontic surgery in cases of ongoing root canal treatment are discussed. A method for retrograde root canal treatment in case of difficult orthograde access is presented. The discussion about root-filled teeth without unsatisfactory healing results occupies lion’s share of this chapter. Special attention is given to the controversies of “success” and “failure” in endodontics. Factors that generally point to a surgical approach to endodontic retreatment are examined. The meaning of informed consent is in particular focus. This chapter ends up with an examination of the medical considerations, which is the basis for the risk assessment of the individual patient compulsory before any endodontic surgery.

Significant advances in the field of surgical endodontics have resulted in more predictable outcomes. A thorough understanding of the etiology of posttreatment endodontic disease will serve as a basis for better surgical treatment. Technically, EMS allows surgeons to have better opportunities to identify and eliminate the etiologies as compared to TES. In this chapter, the variations in outcomes between EMS and TES observed in the literature were identified by contrasting the differences in surgical techniques. A striking difference in success rates between the two surgical treatment modalities exists, and it is explained by the different techniques employed in achieving disinfection and attaining an adequate apical seal. Finally, the results of various outcome studies should be carefully interpreted with a full understanding of prognostic factors, because the hidden heterogeneity in different studies can alter the outcomes significantly.

Anesthesia is the loss of feeling or sensation as a result of an anesthetic agent and is an integral part of any endodontic surgical procedure. In certain cases, local anesthesia (LA) administration may result in complications, ranging from mild discomfort for the patient to catastrophical results and even death.

The complications following LA in endodontic surgery may be regional or systemic and may be related to the local anesthetic itself or to the supplementary vasoconstrictor. Severe systemic complications following LA, such as bronchospasm, seizure, anaphylactic shock, or cardiovascular complications, are rare but may have severe implications on the patient’s general health. Regional LA complications, such as insufficient anesthesia, hematoma, and soft-tissue injuries, are more common, may cause severe discomfort for the patient, and may alter the ability to achieve the surgical goals.

The most important steps in managing untoward reactions to LA are the following: adopt a clinical practice aimed to prevent possible complications, diagnose the problem promptly when it does occur, treat it if necessary, and reassure the patient.

Operator-related factors such as preoperative planning of the surgical procedure, correct flap design, and soft tissue management, as well as patient-related factors such as the gingival biotype and the periodontal condition, may influence the risk of soft tissue complications following endodontic surgery. The clinician should be aware of possible anatomical pitfalls during flap procedure, such as adjacent neurovascular bundles. In order to avoid flap dryness and possible tissue necrosis and delayed healing, it is recommended to perform a short-duration surgery with a constant irrigation of the reflected tissues with saline. Different flap designs may be predisposed to different risks of complications. Intra-sulcular flaps are prone to gingival recession, submarginal and semilunar flaps are prone to scar formation, and a controversy exists whether papilla-based incision is prone to gingival recession and if papilla preservation incision may prevent gingival recession.

The leading measure of successful outcomes in endodontic surgery relies heavily on the ability of the endodontic surgeon to provide conditions that promote resolution of persisting periradicular pathosis. Prevailing criteria for success depend on the preservation and continued function of teeth and radiographic parameters to assess healing (Orstavik, Scand J Dent Res 96:108–11, 1988). However, in an era of high patient expectations, the esthetic consequences of surgical treatment are of paramount concern. Esthetic outcomes are comprised of the natural or idealized shape, color, position, and juxtaposition of teeth to gingival tissues. Esthetic complications of endodontic surgery are best addressed before treatment by careful endodontic diagnosis and periodontal evaluation. This should be followed by adherence to the principle and practice of endodontic microsurgery both at the treatment planning stage and during the surgical procedure. In addition, appropriate surgical management of soft tissues and underlying bony structures is important as persistent endodontic infections are a risk factor for continued marginal attachment loss following endodontic surgery (Jansson et al., Oral Surg Oral Med Oral Pathol Oral Radiol Endod 83:596–601, 1997). While classical measures of success may suggest the positive outcome of a case, failing to achieve an esthetic outcome results in an unhappy patient.

Periapical osteotomy in endodontic surgery is aimed to provide adequate access for a proper surgical management of the apical part of the root. The osteotomy should be as small as possible but as large as necessary to accomplish the endodontic clinical objectives. Therefore, it is prudent to balance between the surgical needs and the case specific limitations, in order to achieve predictable clinical results with minimal associated risks for the patient.

Osteotomy produces heat depending on the drill design, the drilling technique, and the bone structure. Osteotomy based on light brushing motions using sharp high-speed burr, and copious irrigation, may prevent the risk of thermal osteonecrosis.

The possible damage to adjacent teeth during surgery varies from slight surface shaving to a complete root resection. Adjacent teeth should be evaluated before endodontic surgery. In case of damage to adjacent tooth during surgery, the tooth should be closely monitored, and in case of developing signs of pulp necrosis, root canal treatment should be performed.

Periapical curettage may jeopardize adjacent anatomical structures. Early curettage may also result in intraoperative excessive bleeding, and the final thorough curettage can be postponed to the end of the procedure when judged necessary.

Root-end management is a fundamental part of endodontic surgery. It involves a root resection, preparation for the root-end cavity, and obturation of the apical root canal. This phase is critical for the resolution of the periapical pathosis, allowing periradicular tissue regeneration including the formation of a new attachment apparatus.

The management of the root end can be divided into different phases (apex resection, retrograde cavity preparation, and apical sealing). In each phase, several complications can occur due to inadequate planning of the procedure, inappropriate technique, or anatomical characteristics of the site. The success of the entire endodontic surgery may be severely influenced by the occurrence of an adverse event during the root-end management.

Complication prevention and early identification can allow an adequate management of such event, allowing a successful procedure.

The maxillary sinuses are large aerial cavities superior to the oral cavity, which have important implications on oral surgery in general and on endodontic surgery in particular. In cases of maxillary tooth necrosis and infection, microorganisms might be in contact with structures of the maxillary sinus such as Schneiderian membrane, either due to direct contact between the infected tooth apex and the membrane or due to expansion of the bony lesion into the maxillary sinus.

Hence, cases of maxillary tooth infection may lead to sinusitis, a complication with important implications for patients, which should be taken into consideration while planning treatment for tooth infection.

For endodontic surgery, when a periapical lesion involves the maxillary sinus, removal of the infection should be performed carefully, in order to avoid perforation of the sinus membrane or limit its extension. The sinus cavity must be protected during the apical third preparation and while sealing, for avoiding the extrusion of the filling material into the cavity.

As endodontic surgery may involve the maxillary sinus, adequate considerations and measures should be taken while planning and executing the surgery.

Modern endodontic surgery is a highly predictable treatment for teeth with apical periodontitis. While mild hemorrhage during the surgical procedures is common, severe bleeding during endodontic surgery due to an insult to a major blood vessel is relatively rare and may lead to serious systemic complications such as airway compromise, cardiovascular effects, and worsening of the mental status of the patient, and if not controlled may even lead to death. Elderly patients and patients with systemic diseases may be more susceptible to complications following severe blood loss. In addition, in patients with systemic bleeding disorders, excessive bleeding may occur even if only relatively small blood vessels were damaged during the surgical procedure.

Adequate bleeding control is essential for the success of periapical surgery, since it improves visualization of the surgical site, minimizes the operating time, and enables the dry field for retrograde filling material placement. Even mild hemorrhage during endodontic surgery may cause complications during the surgical procedure and may even jeopardize the prognosis of the treatment.

Careful treatment planning and surgical technique, combined with knowledge of the surgical anatomy and recognition of possible hemorrhage related complications, are essential in order to prevent bleeding during endodontic surgery. In addition, a thorough clinical evaluation and anamnesis should be preformed prior to the surgical procedure in order to reveal patients with potential systemic risks of excessive uncontrolled bleeding.

Pain and swelling are common side effects of endodontic surgery, and their intensity depends on the degree of the surgical damage to the tissue.

The pain and swelling are associated with inflammatory responses that are part of the typical wound healing process. Infection of the surgical site may complicate the postoperative sequel, aggravate the symptoms, and may require further pharmacologic and surgical interventions.

Several possible factors may affect the risk and intensity of postsurgical side effects, including patient-related factors and the surgical technique, and this chapter will review methods to prevent and manage postoperative side effects.

Nerve injuries with altered sensations following endodontic surgical procedures represent a rare but serious complication, and the classification of those injuries is based on their time course and on the potential sensory recovery following the injury.

Direct trauma to the nerve bundle during surgery is the most frequent cause of nerve injury and may lead to long-term disability and to significant negative effects on the patient’s quality of life.

Active preventive measures and a timely mannered clinical approach when a nerve injury is suspected are the most efficient measures to minimize the risk for nerve injuries during surgical procedures as well as to prevent permanent damage and enable better clinical and medicolegal outcomes when such injuries do occur.

This chapter is aimed to provide the practitioner with both knowledge and practical tools to prevent and to manage a nerve injury when performing endodontic surgical procedures, thus to enable a safer procedure and a more predictable clinical outcome.

Osteonecrosis of the jaw (ONJ) is a rare condition that has been mainly related to the treatment with i.v. bisphosphonates in patients affected by cancer bone disease. The ethiopathology is still unknown and the frequency is between 0.8 and 12 %. It can appear in edentulous patients, but invasive procedures have been demonstrated to increase the risk of developing this complication. Few cases have been described in the endodontic literature. In the next chapter, we will describe ONJ, will analyze the data from literature, and will report expert opinions and guidelines about the best clinical practice in the endodontic field. Finally, since data in this field are limited, we would like to underline that the best treatment plan for cancer patients receiving bisphosphonates and requiring dental procedures is a multidisciplinary, case-by-case approach.

Patient injuries in relation to medical treatment and in particular conventional or surgical endodontics might under certain circumstances trigger a wish for economical compensation. In many parts of the world, the patient would have to take the practitioner into a civil court to get compensation. However, in a number of countries, there is a legislation which deals with injuries in relation to medical treatment and compensation. Medicolegal considerations in relation to endodontic treatment are in a few countries particularly detailed. Endodontic complaints and insurance cases are relatively frequently occurring. A subcategorization of endodontic complaints shows that the suboptimal root filling represents a potential risk for complaints. Endodontic surgery as an area of claim per se seems lesser involved than conventional endodontics. Statistics about endodontic claims may indicate where risk management and educational efforts can be most effectively directed to improve the standard of care. “Lessons to learn” are presented only in cases where the “complained tooth” has been treated with the use of endodontic surgery.

The concept of guided tissue regeneration (GTR) in endodontic surgery is derived from periodontal regenerative therapy for periodontal disease. Periapical tissue regeneration will occur predictably after endodontic surgery if intra- and extraradicular infections are controlled by adequate root-end resection and complete retrograde seal of the root canal. Indications for GTR technique in endodontic surgery are limited and should be clearly recognized to prevent misuse. They include: combined endodontic-periodontic lesions, through-and-through bone lesions, and large periapical lesions almost involving the alveolar crest bone. The materials, such as barrier membranes and bone grafts used in GTR technique should be biocompatible and approved by the FDA. Possible pre-surgical, intra-surgical, and post-surgical complications of GTR technique in endodontic surgery must be prevented to avoid failures. GTR technique in endodontic surgery could improve periapical wound healing in through-and through bone lesions and possibly in cases with large periapical lesions.