MANAGEMENT OF ROOT PERFORATION
- 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.
- Suppurations resulting in tender teeth, abscesses, and sinus tract including bone resorptive processes may occur.
- Down-growth of gingival epithelium to the perforation site.
Detection of root perforations
- Sudden bleeding from canal (Paper points are useful aids)
- Radiopaque instruments going to the periodontal tissues, confirmed with radiographs or CBCT
- Use of electronic apex locator
- Use of 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
- Careful examination of radiograph
- Shape and depth of pulp chamber
- Width of furcation floor
Before root canal preparation:
- Use of magnification
- Avoid rubber dam before access in teeth with:
- Narrow or calcified pulp chambers
- Crowned teeth
- Pulp chamber is centrally located at the level of 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, GG or Peeso reamers
- Stop when gutta-percha is not coming out from the canal and verify with magnification to see if you are going to the right direction.
Factors of Significance on Prognosis of the Treatment
- Time from the perforation to detection
- Size and shape of the perforation
- Repair material
- Over extrusion of repair material
- Preoperative radiolucency adjacent to perforation site
Ideal material properties for root perforation repair
- Easy manipulation
- Fast setting
- Antimicrobial activity
- Smooth surface
- Adequate sealing
- No discoloration
Materials in the market for root perforation repair
- Composite resin
- Resin modified glass ionomer
- Super EBA
- Zinc Oxide Eugenol / IRM
- MTA and other calcium silicate based materials
Apical level / Mid-root level
- Nonsurgical approach and repair with calcium silicate base material.
- Monitor for signs or symptoms.
- Surgical approach when a periapical lesion develops after monitoring period.
- Prognosis: Fair-Good
Crestal / Furcal level
- Orthodontic extrusion or surgical crown lengthening procedure have been recommended for single-rooted teeth to bring the perforation to a coronal position.
- Nonsurgical approach and repair with composite resin, resin modified glass ionomer or fast set calcium silicate base material in scenarios where the material is not constantly challenged by saliva.
- Prognosis: Poor-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 enhance the success rate to 80.9%.
- Pre-op radiolucency decreases success rate
- Maxillary teeth showed significantly higher success rate after perforation repair than Mandibular teeth (P < .05).