Effect of DTPMP pretreatment on intraradicular dentin push-out bond strength and etching pattern of self-adhesive and conventional dual cure resin cement

Objective

To evaluate the push-out bond strength (PBS) and conditioning effects of diethylenetriamine-penta-phosphonic acid (DTPMP), as a pretreatment of intra-radicular dentin compared to ethylenediamine tetra-acetic acid (EDTA) and orthoorthophosphoric acid 37 % (H3PO4) for cementing posts with dual cure resin cement.

Material and methods

The resin cements employed were dual-cure resin cement RelyX ARC with previous Single Bond Universal adhesive (ARC/SBU) application, and self-adhesive resin cement RelyX U200. A fifty-four bovine incisor roots were prepared for GFP cementation and randomly divided into six groups according to the type of cement and dentin pre-treatment: 1) U200: no previous treatment; 2) EDTA-U200: pretreatment with 15 % EDTA for 3 min; 3) DTPMP-U200: pretreatmentwith 15 % DTPMP for 3 min; 4) H3PO4-ARC: 37 % orthophosphoric acid for 15s + SBU; 5) EDTA-ARC: 15 % EDTA for 3 min + SBU; and 6) DTPMP-ARC: 15 % DTPMP for 3 min + SBU. The roots (n = 6 per group) were sectioned into disc specimens of 1 mm (thickness) and subjected to PBS at 24h and after aging by Clostridium histolyticum. Additionally, root treated with each pre-treatment, without the application of adhesive or cement, disc specimens were subjected to scanning electron microscopy (SEM) to analyze the dentin surface conditioning pattern (n = 3). Data were analyzed by two-way ANOVA and Tukey's test (p < 0.05).

Results

In PBS, DTPMP-U200 and DTPMP-ARC (p < 0.001) presented the highest bond strength after aging. The DTPMP etching pattern showed intense etching with mineral maintenance, while EDTA and H3PO4 showed greater exposure of collagen fibrils.

Conclusions

Treatment using 15 % DTPMP as an intraradicular dentin conditioner before luting glass-fiber posts provides bonding stability and potential for therapeutic remineralization.