Effect of different irrigation solutions and techniques on push-out bond strength of resin-based sealer

Abstract

Aim To evaluate the effect of irrigation solutions [sodium hypochlorite (NaOCl), chlorhexidine (CHX), and normal physiological saline] and different irrigation techniques (conventional needle, EndoVac, and CanalBrush) on push-out bond strength of AH Plus resin-based sealer. Materials and methods Ninety mandibular freshly extracted premolars were selected and divided into three groups according to the irrigation solutions; group I: 5.25% NaOCl, group II: 2% CHX, group III: normal physiological saline solution. Then each group was subdivided into three subgroups according to the irrigation techniques; subgroup A: 27 G side beveled needle, subgroup B: EndoVac irrigating system, subgroup C: medium-sized CanalBrush (30/0.04). Root canals of all groups were prepared using ProTaper Universal Ni-Ti rotary system up to file F4 (40/0.06) and filled by single cone technique using AH Plus sealer. 2 mm thick horizontal sections from the coronal, middle and apical thirds of each root were sliced for the push-out bond strength measurement and tested using universal testing machine. Data were analyzed using one-way analysis of variance in a level of significance (P ≤ 0.05). Results The highest mean push-out bond strength values were recorded for EndoVac system followed by CanalBrush and Needle in all groups and at all root canal levels. In comparison of irrigation solutions in needle subgroup; the highest values were recorded for CHX and least for NaOCl at coronal and middle root levels. While in the apical section, the highest and least mean push-out bond strength values were recorded for CHX and saline respectively. Regarding EndoVac and CanalBrush; the highest push-out bond strength values were recorded for CHX followed by saline and NaOCl at all root canal levels. Conclusions Whenever root canal obturation using AH Plus sealer, it is preferred to use 2% CHX solution throughout and after instrumentation via EndoVac system for improved bond strength. The coronal sections showed higher bond strength than middle and apical sections.