Objectives The EDTMP (ethylenediamine-tetra-methylene phosphonate) is a molecule similar to EDTA (ethylenediamine-tetra-acetic acid), but with phosphonates, thereby presenting efficient chelating action and binding adequately to proteins, such as collagen. The objective of this study was to evaluate EDTMP as new etching solution to aid ion-releasing adhesive containing beta-tri-calcium phosphate (β-TCP) fillers used for intrarradicular dentin bonding. Materials and methods Thirty extracted single-rooted human teeth were prepared, and glass-fiber posts were adhesively luted with Scotchbond Multipurpose (SBMP, 3 M) adhesive after etching with 37% phosphoric acid for 15s, 15% EDTA or 15% EDTMP for 120s, and SBMP adhesive incorporated or not with β-TCP. RelyX ARC (3 M) was used as resin cement. The restored roots were cut horizontally in 1 mm-thick slabs and submitted to push-out bond strength test after 24h and 6 months of water storage. Interfacial silver nanoleakage was investigated in scanning electron microscopy. Micro-Raman spectroscopy was employed to track mineralization at the hybrid layer. Data were submitted to two-way ANOVA and Tukey’s test (p Results EDTMP without β-TCP achieved the overall highest bond strength in both storage times. The addition of β-TCP impaired the improvements of EDTMP. The presence of carbonated apatite (peak at 1090 cm-1) was found in EDTMP without β-TCP, thereby suggesting remineralization. Little silver impregnation was observed in general across groups. Conclusion: EDTMP could be an optimal alternative as root dentin etchant for luting glass-fiber posts with improvements in dentin bond stability.
