The Effects of EDTA on Blood Clot in Regenerative Endodontic Procedures

Introduction: In regenerative endodontic procedures (REPs), a blood clot acts as a natural scaffold for regenerating dental pulp tissue. In current protocols, 17% EDTA is recommended for liberating growth factors from root dentin. Although EDTA affects clot formation in periodontal studies, the anticoagulant effect of EDTA has not been shown in REPs. Therefore, this study aimed to evaluate the effects of 17% EDTA on the characteristics and fiber density of blood clots using in vitro dentin blocks.

Methods: The roots of 35 human mandibular premolars were prepared to simulate open apices and irrigated with the following protocols: (1) normal saline solution (NSS), (2) EDTA (1 minute) + NSS (E1N), (3) EDTA (5 minutes) + NSS (E5N), (4) EDTA (1 minute) (E1), and (5) EDTA (5 minutes) (E5). The roots were split, and human blood was placed. The characteristics and fibrin density of clots were observed using a scanning electron microscope. Fibrin densities in all irrigation groups were evaluated using ImageJ software (National Institutes of Health, Bethesda, MD) and statistically analyzed using the Friedman test and the Kruskal-Wallis test with Bonferroni adjustment.

Results: Samples in the NSS, E1N, and E5N groups revealed denser fibers with an abundance of erythrocytes when compared with those in the E1 and E5 groups. Fiber densities in the E1 and E5 groups showed significantly lower values than those in the NSS, E1N, and E5N groups in all regions of roots (P < .05). No statistically significant difference at all levels was observed in all irrigation groups.

Conclusions: A decrease in clot formation was affected by EDTA irrigation for 1 and 5 minutes. Final flushing with NSS could improve fibrin formation.