Efficacy of Different Irrigation Needles and Ultrasonic Activation on Calcium Hydroxide Removal: A Micro-CT Study Using 3D-Printed Endodontic Models

Abstract

IntroductionThe aim of this study was to evaluate the efficacy of different irrigation needles and passive ultrasonic activation in removing Ca(OH)2 from an endodontic model that duplicated a root canal configuration of a human natural tooth. MethodsAn extracted human maxillary premolar was subjected to root canal preparation and scanned with microcomputed tomography. A 3-dimensional reconstruction model of the natural tooth was printed to endodontic models using a polyjet printer. The root canals of the models were filled with Ca(OH)2 paste and divided into 2 groups based on the irrigation protocol: conventional syringe-needle irrigation (conventional group) and passive ultrasonic irrigation (PUI) group. Each group was subdivided into 3 groups (n = 10) according to the type of needle: half-cut, side-vented, and TruNatomy irrigation needle. Microcomputed tomographyimaging was used to assess the percentage of reduction of Ca(OH)2. Data were analyzed using two-way analysis of variance test (α = .05). ResultsThe side-vented and TruNatomy irrigation needles showed significantly higher percentage reductions than the half-cut needle (P < .05) in the conventional irrigation group. The PUI group showed significantly higher percentage reductions of Ca(OH)2 than the conventional group regardless of the type of needle (P < .05). However, no significant difference was found among the needles in the PUI group. ConclusionsThe type of irrigation needle and the use of PUI influenced the removal efficacy of Ca(OH)2. PUI enhanced the removal of Ca(OH)2 regardless of the type of irrigation needle.