An in vitro study on the determination of moisture content of endodontically treated teeth and analyze the effect of irrigation method on their fracture resistance

Aim: This study aimed to compare the moisture content between endodontically treated and sound teeth and evaluate the effect of different irrigants - 3% Sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic Acid (EDTA), and their combination on fracture resistance. Methods: Twenty-eight mandibular premolars were divided into four groups: Group 1 (control, saline), Group 2 (3% NaOCl), Group 3 (17% EDTA), and Group 4 (combined NaOCl + EDTA). Moisture content was measured by weight difference before and after heating. Fracture resistance was tested using a universal testing machine. Data were analyzed using paired t -tests and one-way ANOVA (SPSS v27.0), with significance set at * P * ≤0.05. Results: Endodontically treated teeth showed significantly lower moisture content (Group IV: 5.75%) compared to controls (7.31%, * P * <0.0001). Fracture resistance was the highest in Group 1 (304.00 N) and lowest in Group 4 (198.00 N, * P * <0.0001). Conclusion: Endodontic treatment reduces moisture content and fracture resistance, with combined NaOCl + EDTA causing the most significant decline. These findings highlight the need for careful irrigant selection to preserve tooth integrity.