The effect of activation of the sequential use of ethylenediaminetetraacetic acid and octenidine dihydrochloride on the release of TGF-β1 in regenerative endodontic treatments.

The aim of this study is to assess the effect of ultrasonic (PUI) and sonic (EDDY) activation of the sequential use of ethylenediaminetetraacetic acid (EDTA) and octenidine dihydrochloride (OCT) on the release of transforming growth factor beta-1 (TGF-β1) from dentin in regenerative endodontic treatments (RET). Seventy-two extracted were decoronated and prepared to an apical diameter of 1 mm to replicate an immature teeth. Each specimen was initially irrigated with 20 mL of 1.5% sodium hypochlorite according to the RET protocol. Samples were assigned to three main irrigant groups (n = 24): 17% EDTA, 0.1% OCT, and 17% EDTA followed by 0.1% OCT. Each main group was further divided into three subgroups (n = 8) based on activation technique-syringe-needle irrigation (SNI), PUI, and EDDY. Levels of TGF-β1 released on days 1 and 7 were quantified by ELISA, and smear layer removal was analyzed under scanning electron microscopy (SEM). Statistical significance was established at p < 0.05. SEM analysis revealed varying degrees of smear layer removal in all groups. The combination of EDTA and OCT resulted in significantly higher TGF-β1 release compared to the use of either solution alone in all activation groups (p < 0.05). TGF-β1 levels were significantly higher at day 7 than day 1 (p < 0.05). EDDY activation with the sequential use of EDTA and OCT yielded the highest TGF-β1 levels and the greatest percentage increase (p < 0.05). Biocompatible irrigation solutions and enhanced activation systems could improve the release of growth factors from dentin, thereby potentially contributing to the overall success of RETs.