title: Effect of passive ultrasonic agitation during final irrigation on cleaning capacity of hybrid instrumentation.
abstract: OBJECTIVE
  To evaluate the effect of passive ultrasonic agitation on the cleaning capacity of a hybrid instrumentation technique.
  
  
  METHODS
  Twenty mandibular incisors with mesiodistal-flattened root shape had their crowns sectioned at 1 mm from the cementoenamel junction. Instrumentation was initiated by catheterization with K-type files (Denstply Maillefer) #10, #15, and #20 at 3 mm from the working length. Cervical preparation was performed with Largo bur #1 (Dentsply Maillefer) followed by apical instrumentation with K-type files #15, #20 and #25, and finishing with ProTaper F2 file (Denstply Maillefer). All files were used up to the working length under irrigation with 1 mL of 2.5% sodium hypochlorite (Biodynâmica) at each instrument change. At the end of instrumentation, the roots were randomly separated into 2 groups (n = 10). All specimens received final irrigation with 1 mL of 2.5% sodium hypochlorite. The solution remained in the root canals in Group 1 for one minute; and ultrasonic agitation was performed in Group 2 for one minute using a straight tip inserted at 1 mm from working length. The specimens were processed histologically and the sections were analyzed under optic microscope (×64) to quantify debris present in the root canal.
  
  
  RESULTS
  The samples submitted to ultrasonic agitation (Group 2) presented significant decrease in the amount of debris in comparison with those of Group 1 (p < 0.05).
  
  
  CONCLUSIONS
  The hybrid instrumentation technique associated with passive ultrasonic agitation promoted greater debris removal in the apical third of the root canals.
authors.affiliation: Department of Endodontics, School of Dentistry, Amazonas State University, Manaus, AM, Brazil.
authors.forename: Marcilene Coelho
authors.initials: MC
authors.lastname: Vinhorte
authors.affiliation: Department of Endodontics, School of Dentistry, Amazonas State University, Manaus, AM, Brazil.
authors.forename: Eduardo Hideki
authors.initials: EH
authors.lastname: Suzuki
authors.affiliation: Department of Endodontics, School of Dentistry, Federal University of Amazonas, Manaus, AM, Brazil.
authors.forename: Maíra Sousa
authors.initials: MS
authors.lastname: de Carvalho
authors.affiliation: Department of Endodontics, School of Dentistry, Amazonas State University, Manaus, AM, Brazil.
authors.forename: André Augusto Franco
authors.initials: AA
authors.lastname: Marques
authors.affiliation: Department of Endodontics, School of Dentistry, Federal University of Amazonas, Manaus, AM, Brazil.
authors.forename: Emílio Carlos
authors.initials: EC
authors.lastname: Sponchiado Júnior
authors.affiliation: Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Lucas da Fonseca Roberti
authors.initials: Lda F
authors.lastname: Garcia
keywords: Ni-Ti; ProTaper; Sodium hypoclorite; Ultrasonic