Management of Root Perforation

Definitions

  • Root perforation is an artificial communication between the root canal system to the supporting tissues of teeth or to the oral cavity. (AAE Glossary)
  • Accidental root perforations, which may have serious implications, occur in approximately 2–12% of endodontically treated teeth, according to Ingle, Kerekes, Seltzer and many other authors.

Causes of Perforations

  • Misaligned use of rotary burs during endodontic access preparation and search for root canal orifices.
  • Negotiating calcified and curved canals.
  • Lateral extension of the canal preparation (to a so-called strip perforation).
  • Inappropriate post space preparation.

Signs and Symptoms of Perforations

  • Sudden bleeding and pain during instrumentation of root canals or post preparations in teeth are warning signals of a potential root perforation.
  • Suppuration resulting in tender teeth, abscesses, sinus tracts, and bone resorptive processes may occur.
  • Down-growth of gingival epithelium to the perforation site.

Detection of Root Perforations

  • Sudden bleeding from the canal (paper points are useful aids).
  • Radiopaque instruments extending into the periodontal tissues, confirmed with radiographs or CBCT.
  • Use of an electronic apex locator.
  • Use of an operating microscope for additional illumination and magnification.
  • A narrow isolated deep pocket (in long-standing root perforations).

Sequels of Root Perforation

  • Bacterial infection emanating either from the root canal or the periodontal tissues, or both, prevents healing.
  • Once an infectious process has established itself at the perforation site, prognosis for treatment is precarious and the complication may prompt extraction of the affected tooth.

Measures for Prevention

Before Accessing Canals

  • Check crown-root alignment.
  • Carefully examine radiographs.
    • Evaluate the shape and depth of the pulp chamber.
  • Evaluate the width of the furcation floor.

Before Root Canal Preparation

  • Use magnification.
  • Avoid placing the rubber dam before access in teeth with:
    • Narrow or calcified pulp chambers.
    • Crowned teeth.
  • Remember that the pulp chamber is centrally located at the level of the CEJ.

During Root Canal Preparation

  • Avoid overzealous preparation.
  • Use flexible instruments with copious irrigation and lubrication.

During Post Space Preparation

  • Avoid excessive pressure with post drills, Gates-Glidden (GG), or Peeso reamers.
  • Stop when gutta-percha is no longer coming out of the canal, and verify with magnification that you are proceeding in the correct direction.

Factors Affecting Prognosis

  • Time from perforation to detection.
  • Size and shape of the perforation.
  • Location.
  • Repair material.
  • Overextrusion of repair material.
  • Preoperative radiolucency adjacent to the perforation site.

Ideal Material Properties for Root Perforation Repair

  • Biocompatible.
  • Easy manipulation.
  • Hydrophilic.
  • Fast setting.
  • Insoluble.
  • Antimicrobial activity.
  • Smooth surface.
  • Adequate sealing ability.
  • No discoloration.
  • Radiopaque.

Materials Used for Root Perforation Repair

  • Amalgam.
  • Composite resin.
  • Resin-modified glass ionomer.
  • Cavit.
  • Super EBA.
  • Zinc Oxide Eugenol / IRM.
  • MTA and other calcium silicate-based materials.

Treatment Modalities

Apical Level / Mid-Root Level

  • Nonsurgical repair using a calcium silicate-based material.
  • Monitor for signs and symptoms.
  • Surgical intervention if a periapical lesion develops after the monitoring period.
  • Prognosis: Fair to Good.

Crestal / Furcal Level

  • Orthodontic extrusion or surgical crown lengthening may be recommended for single-rooted teeth to reposition the perforation coronally.
  • Nonsurgical repair using composite resin, resin-modified glass ionomer, or a fast-setting calcium silicate-based material when the repair site is not continually exposed to saliva.
  • Prognosis: Poor to Fair.

Reported Success Rates

  • According to the systematic review and meta-analysis by Siew et al. (JOE, 2012):
  • An overall pooled success rate of 5% (confidence interval: 61.9%–81.0%) was estimated for nonsurgical repair of root perforations.
  • The use of MTA appeared to increase the success rate to 80.9%.
  • Preoperative radiolucency decreases the success rate.
  • Maxillary teeth demonstrated significantly higher success rates than mandibular teeth (P < .05).