Fracture resistance of teeth obturated with different root canal sealers: a systematic review

Endodontically treated teeth are more prone to fracture due to structural loss during canal preparation and alterations in dentin biomechanics. Root canal sealers and obturation materials contribute not only to sealing ability but also to potential reinforcement of the remaining tooth structure. However, their influence on fracture resistance remains unclear due to variability in study designs and outcomes.

To systematically evaluate and synthesize the available evidence on the fracture resistance of endodontically treated teeth obturated with different root canal sealers and materials.

A comprehensive search was conducted across MEDLINE (via PubMed), Scopus, Web of Science, and the Cochrane Library, supplemented by grey literature from Google Scholar. A total of 549 records were identified, of which 24 studies met the eligibility criteria and were included in the qualitative synthesis. Among these, 22 were in vitro studies, one was an in vivo animal study, and one was an ex vivo study. Two independent reviewers performed study selection and data extraction. Due to methodological heterogeneity, a qualitative synthesis was performed.

Obturation with root canal sealers generally improved fracture resistance compared with instrumented but unobturated controls, indicating a reinforcing effect. Epoxy resin-based and calcium silicate-based sealers demonstrated comparable performance, while zinc oxide eugenol-based sealers showed limited reinforcement. Considerable heterogeneity in tooth selection, loading conditions, and testing protocols limited direct comparisons.

Root canal sealers appear to enhance the mechanical strength of endodontically treated teeth; however, no specific sealer demonstrates clear superiority. Standardized experimental models and clinical studies are needed to determine their clinical significance.

Unique Identifier, CRD420251163273.