Effect of chelating agents on the molecular composition and extent of decalcification at cervical, middle and apical root dentin locations

The aim of this study was to investigate the interaction of two chelating a gents used in endodontic treatment with dentin from different root location s. Standardized cervical, middle and apical root dentin specimens were prep ared and subjected to treatment with 15% neutral EDTA and RCPrep. Following rinsing with water, dentin surfaces were studied by reflected light optica l microscopy and micro-MIR FTIR spectroscopy, while the wash-off extracts w ere analyzed by atomic absorption spectrometry (AAS) to determine the conte nt of calcium and phosphorus. Neutral EDTA removed the smear layer and open ed tubules while RCPrep did not. FTIR measurements showed higher decalcific ation of dentin surfaces after neutral EDTA treatment although its effect w as reduced at apical regions. AAS measurements of calcium and phosphorus co nfirmed the higher dentin dissolution potential of EDTA at cervical and mid dle root dentin locations. The results of the present study implied differe nt reaction modes for the two chelating agents tested which might affect th e efficiency of the chemomechanical preparation when these agents are used.