title: Assessment of smear layer removal protocols in curved root canals.
abstract: This study sought to assess if the final rinse protocol interferes with the smear layer removal in the apical area of curved canals. Sixty-four extracted human mandibular molars with curved mesial roots were instrumented with rotary files and divided into six experimental groups for final rinse: 1EDTA (syringe irrigation with 1 mL of 17% ethylenediaminetetraacetic acid (EDTA) ), 5EDTA (syringe irrigation with 5 mL of 17% EDTA), 1EDTA-P (syringe irrigation with 1 mL of 17% EDTA + pumping with gutta-percha point), 5EDTA-P (syringe irrigation with 5 mL of 17% EDTA + pumping with gutta-percha point), 1EDTA-EA (syringe irrigation with 1 mL of 17% EDTA + EndoActivator) and 5EDTA-EA (syringe irrigation with 5 mL of 17% EDTA + EndoActivator). Final rinsing was carried out over 3 min. The specimens were split lengthwise and observed under a scanning electron microscope using a score criterion. Comparison among the groups showed statistically significant difference only between the 5EDTA-EA group and the other groups (Kruskal-Wallis and Dunn's post-hoc tests, P < 0.05). The combination of 5 mL of 17% EDTA and 3 mL of 2.5% sodium hypochlorite (NaOCl) with the EndoActivator removed smear layer from the apical area of curved root canals more effectively than the other protocols used.
authors.affiliation: Private Practice, Vancouver, British Columbia, Canada.
authors.forename: William
authors.initials: W
authors.lastname: Yeung
authors.forename: Denise Pontes
authors.initials: DP
authors.lastname: Raldi
authors.forename: Rodrigo Sanches
authors.initials: RS
authors.lastname: Cunha
authors.forename: Isabel
authors.initials: I
authors.lastname: Mello
mesh_terms: D003786:Dental Pulp Cavity / Q000187:drug effects / Q000473:pathology*; D004492:Edetic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D016369:Smear Layer / Q000188:drug therapy* / Q000473:pathology; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000627:therapeutic use; D013010:Sonication / Q000295:instrumentation; D013594:Syringes; D007507:Therapeutic Irrigation / Q000295:instrumentation; D013997:Time Factors; D019227:Tooth Apex / Q000187:drug effects / Q000473:pathology*
chemical_list: D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite
keywords: EDTA; irrigation; root canal; smear layer; sonication