Effect of QMix irrigant on bond strength of glass fibre posts to root dentine

Abstract

Aim: To investigate the effect of QMix irrigant compared with several other irrigating solutions on the bond strength of glass fibre posts to root dentine and on smear layer removal after post space preparation.

Methodology: One hundred and fifty single-rooted teeth were used. The specimens were divided into six groups in each test according to the irrigation regimen used: group 1, distilled water; group 2, 5.25% sodium hypochlorite (NaOCl); group 3, 2% chlorhexidine digluconate (CHX); group 4, 17% ethylenediaminetetraacetic acid (EDTA); group 5, 17% EDTA followed by 2% CHX; and group 6, QMix. Dual-cure self-adhesive resin cement (i CEM; Heraeus Kulzer, Hanau, Germany) was used for testing the adhesion of glass fibre post (Reblida; VOCO, Cuxhaven, Germany) to root dentine using a micropush-out test. Debonding specimens were examined with a scanning electron microscope. Scanning electron microscopy was also used to examine and score the treated specimens for debris removal and dentinal tubule opening. Micropush-out data were analysed using anova and Tukey's test. Debris and dentinal tubule opening scores were analysed with the Kruskal-Wallis and Mann-Whitney U-tests.

Results: QMix and 17% EDTA/2% CHX demonstrated the highest mean bond strength values in all root levels amongst the groups. Most failure modes were adhesive type of failures between post and luting material (42.6%). QMix, 17% EDTA and 17% EDTA/2% CHX performed significantly better than the other groups on smear layer removal and dentinal tubule opening.

Conclusion: QMix is an effective irrigant that can remove smear layer, open dentinal tubules and simplify the irrigation protocol, without compromising the bonding strength of glass fibre posts cemented with a self-adhesive resin cement to root dentine.

Keywords: QMix; glass fibre post; irrigation; push-out; resin cement; smear layer.