Perforations are unfavorable iatrogenic complications that may occur during endodontic treatment or post-space preparation. Such events have been shown to occur in 2% to 12% of all endodontically treated teeth. The factors that may contribute to coronal perforations include:
■ pulp chamber calcifications
■ unfavorable crown-root angulations
■ excessive removal of coronal dentin
■ oversized post-space preparation
■ poorly angled post-space preparation Factors that may contribute to mid-root and apical perforations include
■ excessive flaring of coronal canal
■ overzealous instrumentation of curved canals
■ attempted negotiation of blocked, transported or ledged canals
Perforations may lead to breakdown of the periodontium, resulting in alveolar bone loss and pocket formation. Previous studies have shown that teeth subjected to perforations have success rates of 54% to 86%. However, most previously reported studies have had a small sample size and relatively short-term follow-up periods.
Pontius et al from the University of Marburg, Germany, evaluated the healing outcome of perforation repairs (70 perforation repairs, 69 patients) performed by 6 endodontic specialists in 6 private practices between 1998 and 2010 using a non-surgical or combined nonsurgical/ surgical approach. Treatments were performed with the aid of a dental operating microscope.
Recalls of months were obtained on 49 patients (50 teeth). Two calibrated observers evaluated the radiographic results on recalls up to 9.7 years, with a mean of 37 months. Pre-, intra- and postoperative data were evaluated with respect to treatment outcomes and possible prognostic factors.
Successful outcomes were defined as follows:
■ no indication of apical periodontitis
■ no radiolucency adjacent to the perforation site
■ no continuing root resorption
■ absence of clinical signs and symptoms
■ no loss of function
Forty-seven of 50 teeth (94%) had no clinical symptoms and were rated “functional.” The statistical evaluation identified significant differences for the location of the perforation, preoperative radiographic coronal status and gender. The location of the perforation was found to be a significant prognostic factor for success (p = .03).
Each of the failed cases exhibited perforations at or close to the level of the osseous crest. Additionally, teeth with coronal restorations that were rated “unacceptable” before intervention were associated with a higher failure rate (p = .02). When combining radiographic and clinical findings, 45 of 50 teeth (90%) were rated as successful.
This retrospective study of 50 cases produced a success rate of 90% from a collection of perforation repairs performed in 6 different practices. Within the limits of this investigation, the location of the perforation, the coronal status of the restoration and the gender of the patient were factors that significantly affected the outcome. However, the high success rate of the perforation repairs must be viewed with caution because 40% of these teeth had recall periods of