ABSTRACT
The aim of this study was to compare the cleaning efficacy of three irrigant activation devices with a control of non-activated syringe and needle irrigation in curved root canals. Sixty human curved roots were endodontically prepared and divided into four groups (n = 15) with similar root curvature distributions. Final irrigation using 4% NaOCl was performed with a syringe and needle (30-G) alone, or with Eddy sonic powered irrigation system (polymeric tip #0.25/0.06), Endosonic ultrasonic activation (polymeric tip #0.25/0.03), or Irrisafe ultrasonic activation (stainless-steel tip, #0.25/0.00). SEM was used to evaluate cleaning efficacy, employing five-score systems for debris and smear layer. While no significant difference in debris removal was observed between Endosonic or Irrisafe activation and non-activated irrigation, Eddy sonic powered irrigation system significantly improved debris removal in the apical third of curved root canals. Smear layer removal was effective in coronal and mid-root sections for all groups but less so in the apical third. Thus, Eddy sonic powered irrigation system demonstrated higher efficacy in removing debris from the apical third of curved root canals compared with non-activated syringe and needle irrigation. However, all three irrigant activation systems exhibited no difference from the non-activated control in smear layer removal.
ABSTRACT
Background: Irrigation is an essential component of root canal treatment to enable cleaning beyond the reach of mechanical instruments. The study aimed to assess and compare the efficacy of different final irrigation protocols, including sonic- and ultrasonic-powered irrigant-activation systems, on debris and smear layer removal in the coronal, middle, and apical thirds of straight oval root canals. Materials and Methods: Straight oval root canals of 60 human mandibular incisors were prepared to size 40.04 and divided into four groups (n = 15) according to the final irrigation protocols: (a) Eddy sonic activation (b) endosonic passive ultrasonic irrigation (PUI), (c) irrisafe PUI, and (d) manual syringe and needle irrigation with no additional activation, which served as control. After the treatment procedures, the roots were split and observed using scanning electron microscopy. The presence of remaining debris and smear layer at the coronal, mid-root, and apical thirds of the canals were evaluated using a score system and statistically analyzed using multinominal models with significance level set at p < 0.05. Results: None of the final irrigation protocols completely removed all debris and smear layer from all root canals. When the syringe and needle were used without activation, more debris and smear layer were found in the apical third of the canals. Activation of the final irrigant with each of the three devices significantly reduced the presence of debris in the apical third, compared to the syringe and needle final irrigation, with no difference among the three activation devices. Eddy and irrisafe activation also significantly reduced the residual smear layer in the apical third, compared to syringe and needle alone, while the reduction in the remaining smear layer by endosonic activation did not reach the significance level. Conclusions: Removal of debris and smear layer from the apical part of the root canal by syringe and needle irrigation alone may be significantly improved by using sonic or ultrasonic activation of the final irrigant. Endosonic activation was less effective in removal of smear layer from the apical part of the canals compared to the other two activation systems.
