Analysis of factors related to extraction of endodontically treated teeth

Endodontic therapy is a predictable treatment, resulting in up to 97% retention rate for the treated teeth. However, about 3% of endodontically treated teeth require further treatment, including extraction of the tooth.

This retrospective study analyzed all endodontically treated permanent teeth that were extracted in a multidisciplinary clinic in 2006-2007 (n = 547). Associations among the extractions' indications and the patients' gender, education, and smoking status, as well as tooth type and coronal restoration, were investigated.

Of the 547 endodontically treated teeth that were subjected to extraction, mandibular (44.6%) and maxillary (20.5%) first molars were the most common. Fifteen percent of the extracted teeth were restored with a crown, whereas 57.4% of the extracted teeth did not have a permanent coronal restoration. The reasons for extraction were nonrestorable caries (61.4%), endodontic failure (12.1%), vertical root fracture (8.8%), iatrogenic perforation (8.8%), periodontal disease (4.6%), unrestorable cusp fracture (2.4%), orthodontic (1.3%), and prosthetic (0.2%) considerations and dental trauma (0.5%). Periodontitis was more prevalent among current smokers than among nonsmokers (P < .05). Gender and education had no influence on the extraction of the tooth. Vertical root fracture was more prevalent in mandibular than in maxillary first molars (P < .05). Caries was more prevalent in unrestored teeth than coronally restored or crowned teeth (P = .001). Endodontic failure and VRF were more prevalent in restored than in unrestored teeth (P < .05).

The most common extracted tooth profile was the mandibular first molar without permanent coronal restoration, which was lost due to caries destruction. Endodontically treated teeth were prone to extraction mainly due to nonrestorable carious destruction and to a lesser extent to endodontic-related reasons such as endodontic failure, VRF, or iatrogenic perforation.