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The Endodontically Perforated Tooth: Hopeless or Savable?
Louis E. Rossman, DMD; James Bahcall, DMD, MS, FICD, FACD; and Frederic Barnett, DMD
Should endodontically perforated teeth be extracted or saved?
The clinician should definitely attempt to save the endodontically perforated tooth, according to the American Association of Endodontists’ Treatment Options for the Compromised Tooth: A Decision Guide.1 The treatment condition is favorable if the issue is at the apex with no sulcular communication or osseous defect, the repair is performed immediately, and the perforation is small (relative to the tooth and location). The treatment condition is questionable if the problem is mid-root or furcal with no sulcular communication or osseous defect, the repair was delayed, and the perforation is larger. For an unfavorable treatment condition, there would be apical, crestal, or furcal perforation with sulcular communication and a probing defect with osseous destruction, delay with no repair or gross extrusion of the repair materials, and a large perforation.
Preserving natural tooth remains the best treatment decision. Endodontically perforated teeth can be categorized as coronal and root structure. Further division includes iatrogenic and pathogenic. Each can determine the prognosis, which depends on three factors:
• How quickly it is sealed
Location: If the perforation is close to the crestal bone, inflammation can result, creating epithelial downgrowth and communication with the oral environment. When this occurs, the prognosis is poor.
If the perforation occurs in an area of the coronal structure that is surrounded by healthy bone, it is small and can be sealed immediately, leading to a better prognosis. Sufficient bone is available to endure the inflammation and create an environment for healing.
Size: For osseous repair, the smaller the perforation, the better the prognosis.
Quick seal: If there is healthy surrounding bone, a small perforation that is immediately sealed to prevent bacteria contamination provides the best prognosis. Bacterial infiltration and the resulting inflammation create the defect that destroys a good prognosis. Immediate sealing of the perforation by biologically proven materials such as mineral trioxide aggregate (MTA) or a bioceramic material offers the best surface for osseous repair.
Other perforations can be from a post or a strip perforation created during aggressive instrumentation of the canal system. The prognosis is favorable if the perforation is small and no sulcular communication or osseous destruction is observed.
A tooth perforation is a pathologic or iatrogenic communication between the root canal space and the periodontal apparatus.2 To clinically determine if an endodontically perforated tooth should be extracted or saved, the clinician must first understand the prognosis and treatment. The biologic response of a perforated tooth is inflammatory and can cause a breakdown of the osseous and periradicular tissues. This can lead to a guarded long-term prognosis for the tooth. Much depends on the location, size, and time from occurrence.3 The more apical the perforation, the better the prognosis, but the more difficult the direct repair is. The larger the perforation, the more difficult sealing can be. The immediate sealing of a perforation is paramount to help prevent infection from communicating with the surrounding periradicular tissue.4
The clinical treatment protocol for repairing a tooth perforation is either performed internally or externally. Internal repair is treatment within a root canal and can be divided into perforations that can be directly visualized (coronal one-third) or not directly visualized (middle and apical one-third). If the perforation cannot be directly visualized, the root-canal treatment should be completed and then obturated with gutta-percha and a bioceramic-type sealer. Due to the perforation, anesthetic solution or sterile saline should be used as an irrigant instead of sodium hypochlorite.5
In cases of perforation that can be directly visualized (coronal one-third), a matrix should be used to fill the perforation before placing a permanent restoration. Unintentional extrusion of a restorative material into the alveolar bone may further compromise the prognosis of the perforated tooth. This overfill can produce an additional inflammatory and foreign-body reaction.6 Because the matrix material is intended for placement in bone and not within tooth structure, this material should be biocompatible. Use of MTA, calcium sulfate, or other bioceramic materials as matrix materials has been reported in the literature.2
External or surgical repair of a perforation is necessary when either the internal repair cannot properly seal the perforation or the perforation was not sealed in a timely fashion and clinical evidence indicates the periradicular tissue is beginning to break down.7 If this breakdown of tissue has advanced and the tooth has become severely compromised, extraction is usually the treatment of choice.
Tooth perforation is an iatrogenic complication that may occur during endodontic-access cavity preparation, root-canal instrumentation, or post-space preparation. Kvinnsland et al8 found 47% of perforations occurred during endodontic treatment and 53% were due to restorative/prosthodontic treatment.
Such perforations may result in periodontal breakdown, compromising the long-term health and survival of the involved tooth. As such, some have advocated extraction of the tooth. Alternatively, other clinicians have observed favorable healing and long-term survival of properly repaired perforations using a variety of dental materials.
Factors that have been associated with unfavorable periodontal breakdown as a result of perforation are:
• Location of the perforation: Coronal perforations are less favorable than apical.
• Size: Large perforations appear to be less favorable than small ones.
• Timing of repair: Delayed repair of perforations has been associated with attachment loss.
• Contamination: Coronal (microbial) leakage in teeth with untreated perforations has been associated with persistent inflammation and attachment loss.
• Repair materials: The use of bioactive materials (eg, MTA, bioceramics, Biodentine® [Septodont, septodontusa.com]) has been associated with more favorable outcomes than alloy. A recent systematic review and meta-analysis9 on treatment outcome of repaired perforations reported the following:
• The overall success rate was 72.5% after non-surgical repair of perforations.
• The use of MTA increased the success rate to 80.9%.
• The presence of preexisting radiolucencies adjacent to the perforation sites was associated with decreased success rates.
The favorable success rate associated with the non-surgical repair of perforations (>80% when using bioactive materials) warrants appropriate consideration and discussion between the treating practitioner and the patient.
About the Authors
Louis E. Rossman, DMD
Foundation for Endodontics
American Board of Endodontics
James Bahcall, DMD, MS, FICD, FACD
College of Dentistry
Department of Endodontics
University of Illinois-Chicago
Diplomate, American Board of Endodontics
Frederic Barnett, DMD
Maxwell S. Fogel Department of Dental Medicine
Chairman and Program Director
IB Bender Division of Endodontics
Albert Einstein Medical Center
1. American Association of Endodontists. Treatment Options for the Compromised Tooth: A Decision Guide. https://www.aae.org/uploadedfiles/clinical_resources/treatment_planning/2014treatmentoptionsguidefinalweb.pdf. Accessed February 26, 2016.
2. Gorni FG, Andreano A, Ambrogi F, et al. Patient and clinical characteristics associated with primary healing of iatrogenic perforation after root canal treatment: results of a long-term Italian study. J Endod. 2016;42 (2):211-215.
3. Tsesis I, Rosenberg E, Faivishesky V, et al. Prevalence and associated periodontal status of teeth with root perforation: a retrospective study of 2,002 patients’ medical records. J Endod. 2010;36(5):797-800.
4. Fuss Z, Trope M. Root perforations: classification and treatment choices based on prognostic factors. Endod Dent Traumatol. 1996;12 (6):255-264.
5. Roda RS, Gettleman BH. In: Hargreaves KM, Cohen S, Berman LH, eds. Cohen’s Pathways of the Pulp. 10th ed. St. Louis, MO: Mosby Elsevier:941-942.
6. Alhadainy HA, Himel VT. Comparative study of the sealing ability of light-cured versus chemically cured materials placed into furcation perforations. Oral Surg Oral Med Oral Pathol. 1993;76(3):338-342.
7. Roda RS. Root perforation repair: surgical and nonsurgical management. Pract Proced Aesthet Dent. 2001;13(6):467-472.
8. Kvinnsland I, Oswald RJ, Halse A, Grønningsaeter AG. A clinical and roentgenological study of 55 cases of root perforation. Endod J. 1989;22 (2):75-84
9. Siew K, Lee AH, Cheung GS. Treatment outcome of repaired root perforation: a systematic review and meta-analysis. J Endod. 2015;41(11):1795-1804.