Apicaldebrisextrusionmaybeclinicallyassociatedwithpain and/or swelling in the presence of an intense inflammatory response [1]. This extrusion is an undesired consequence of themechanicalinstrumentationoftherootcanal,andnoneof theavailableinstrumentationsystemscanavoidapicaldebris extrusion.Thus,methodstominimizethisphenomenonare continuously investigated [2]. Apical debris extrusion has been demonstrated to vary based on kinematics, number of files used, taper, cross section, and cutting efficacy [3], and these findings justify the need for an analysis of the widely usedsystems. The Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply/Maillefer, Ballaigues, Switzerland) single-file systems feature a specific motor that performs the reciprocating motion (i.e., movements alternating clockwise and counterclockwise)andarerecommendedforsingleuse.Both systems are made of heat-treated nickel-titanium (Memory Wire, Dentsply Tulsa Dental Specialties, Tulsa, OK, USA), whichisresistanttofatigue[4].Thereciprocatingmotionalso improvestheresistanceofthenickel-titaniuminstrumentto cyclicalfatigue[5]. TheHyFlexCMmultiple-filesystem(ColteneWhaledent, CuyahogaFalls,OH,USA)wasdevelopedforuseincontinuousrotationandiscomposedofamodifiedNiTialloy(52Ni wt%versus54.5–57Niwt%inconventionalNiTialloys).This alloyundergoesControlledMemory(CM)thermomechanical surface treatment, which increases the fatigue resistance by150%and390%comparedwithM-Wireandnon-surfacetreated conventional NiTi alloy, respectively [6]. Due to the lackofshapememory,thissystemenablesvisualfunctionality verification.Theshapeandstrengthoffileswithstraightened spirals can be restored during autoclaving and reused, but
| Autor: Giselle Nevares Elgarten Rocha | Currículo Lattes |
| Co-autor: Felipe Xavier | Currículo Lattes |
| Co-autor: Luciana Gominho | Currículo Lattes |
| Co-autor: Flávia Cavalcanti | Currículo Lattes |
| Co-autor: Marcely Cassimiro | Currículo Lattes |
| Co-autor: Kaline Romeiro | Currículo Lattes |
| Co-autor: Pamela Alvares | Currículo Lattes |
| Co-autor: Gabriela Monteiro Queiroz | Currículo Lattes |
| Co-autor: Ana Paula Sobral | Currículo Lattes |
| Co-autor: Marleny Gerbi | Currículo Lattes |
| Co-autor: Márcia Silveira | Currículo Lattes |
| Co-autor: Diana Albuquerque | Currículo Lattes |
