title: Ex vivo evaluation of three instrumentation techniques on E. faecalis biofilm within oval shaped root canals.
abstract: The objective of the present study was to assess the effectiveness of reciprocating instrumentation in disinfecting oval-shaped root canals infected with Enterococcus faecalis. Forty-five human lower premolars were infected with a culture of E. faecalis (ATCC 29212) for 28 days. Five other teeth that were neither contaminated nor instrumented were used as controls. The 45 specimens were divided into three experimental groups (n = 15) based on the root canal preparation technique used: manual (K-type, Dentsply Maillefer, Ballaigues, Switzerland); rotary (MTwo, VDW GmbH, Munich, Germany); and reciprocating (Reciproc R50, VDW GmbH, Munich, Germany) instruments. During chemomechanical preparation, 21 mL of 2.5% NaOCl was used as the irrigating solution. Microbiological sampling was performed before (S1) and immediately after (S2) the chemomechanical preparation using sterilized paper points. Specimens were then cleaved, and 0.02 g of dentine chips was collected from the root thirds to verify the presence of microorganisms in dentinal tubules. All three preparation techniques reduced the number of microorganisms in the root canal lumen and dentine chips from the root thirds, but no significant differences were observed between the three groups (p > 0.05). Reciprocating instrumentation with Reciproc R50 was effective in reducing the number of microorganisms within the root canal system. Although this technique involves the use of only one file to perform the root canal therapy, it is as effective as conventional rotary instrumentation in reducing the E. faecalis biofilm from the root canal system. However, further clinical investigations are warranted in order to ratify these results.
authors: Department of Dentistry, Dental School, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: Vitor Cesar
authors: VC
authors: Nakamura
authors: Department of Dentistry, Dental School, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: George Taccio de Miranda
authors: GT
authors: Candeiro
authors: Department of Microbiology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: Silvana
authors: S
authors: Cai
authors: Department of Dentistry, Dental School, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: Giulio
authors: G
authors: Gavini
mesh_terms: D058491:Bacterial Load; D018441:Biofilms / Q000187:drug effects; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000382:microbiology*; D004203:Disinfection / Q000295:instrumentation / Q000379:methods; D013293:Enterococcus faecalis / Q000187:drug effects / Q000502:physiology*; D004867:Equipment Design; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology / Q000628:therapy*; D006801:Humans; D015203:Reproducibility of Results; D012388:Root Canal Irrigants / Q000494:pharmacology; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D012973:Sodium Hypochlorite / Q000494:pharmacology; D018709:Statistics, Nonparametric
chemical_list: D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite