Effect of different final irrigation solutions on the fracture strength of endodontically treated premolars: An ex vivo study

Purpose: New solutions are needed to overcome the disadvantages of irrigation solutions that are frequently used to remove the inorganic part of the smear layer. The goal of the current study was to compare the effect of 5%, 10%, and 17% GA, 9% HEBP, 17% EDTA, and 10% CA on the fracture strength of endodontically treated premolars.
Methods: Eighty-eight mandibular premolar teeth were selected. Eleven intact specimens were preserved as negative controls. After root canal preparation, the specimens were divided into 8 groups for the final irrigation procedure: Positive control (distilled water), 17% EDTA, 10% CA, 9% HEBP, 5% GA, 10% GA, and 17% GA (n = 11). After the final irrigation procedure, the root canals were obturated. Access cavities were filled with composite resin. A universal testing machine was used to measure the force required to fracture the specimens. Data were statistically analyzed.
Results: The negative control group showed higher fracture strength than all other groups except the positive control group (p < 0.05). There was no statistically significant difference among the EDTA, CA, HEBP, and GA groups (p > 0.05).
Conclusion: Within the limitations of this study, 1-minute use of 17% EDTA, 10% CA, 9% HEBP, 5% GA, 10% GA, and 17% GA as final irrigation solutions, in combination with NaOCl, had no effect on the fracture resistance of premolar teeth.