Resumo Este estudo objetivou avaliar in vivo a precisão dos localizadores foraminais eletrônicos (EFLs) Raypex 5 e Root ZX em presença de sangue no canal radicular. Foram utilizados 40 dentes unirradiculares destinados a extração. Foi preparada cavidade de acesso e feita ampliação coronária. Cerca de duas gotas de sangue obtidas por punção digital foram injetadas no canal. O comprimento eletrônico de trabalho (EWL) foi medido duas vezes antes (Grupo NB) e depois (Grupo WB) da injeção do sangue. O dente foi extraído e o comprimento real de trabalho (AWL) foi determinado. Os dados foram analisados com o teste de McNemar. As taxas de precisão a ±0,5 mm de Raypex 5 e Root ZX foram 88,9% and 91,5% no Grupo NB, e 83,3% e 86,2% para o Grupo WB, respectivamente. Não houve diferença significativa entre a precisão de cada um dos EFLs em ambos os grupos (p>0,05). Considerando os grupos NB e WB, não houve diferença significativa entre as precisões dos EFLs (p>0,05). A presença de sangue no canal radicular não influencou a precisão dos EFLs.

Abstract The aim of this study was to evaluate in vivo the accuracy of the Raypex 5 and Root ZX electronic foramen locators (EFLs) in the presence of blood in the root canal space. Forty single-canal teeth scheduled for extraction were selected. Access cavity was prepared and coronal enlargement was carried out. Approximately two drops of blood were collected by finger prick and injected into the root canal space. The electronic working length (EWL) of each tooth by each device was established twice before (NB group) and after (WB group) injecting blood into the root canal. The tooth was extracted and the actual working length (AWL) was determined. Data were analyzed using McNemar's test. The accuracy rates of Raypex 5 and Root ZX within 0.5 mm in the NB group were 88.9% and 91.5%, with 83.3% and 86.2% in the WB group, respectively. There were no significant differences between the accuracy of each EFL in the two groups (p>0.05). Considering the NB and WB groups, there were no statistically significant differences in the accuracy of the EFLs (p>0.05). The presence of blood in the root canal space did not influence the accuracy of the EFLs.

Objective: Enterococcus faecalis (E. faecalis) is the most frequently isolated strain in failed endodontic therapy cases since it is resistant to calcium hydroxide (CH). Whether a combination of CH and chlorhexidine (CHX) is more effective than CH alone against E. faecalis is a matter of controversy. Thus, the aim of this study was to conduct a systematic review and meta-analysis of the literature. Material and Methods: A comprehensive search in PubMed, EMbase, EBSCOhost, The Cochrane Library, SciELO, and BBO databases, Clinical trials registers, Open Grey, and conference proceedings from the earliest available date to February 1, 2013 was carried out and the relevant articles were identified by two independent reviewers. Backward and forward search was performed and then inclusion and exclusion criteria were applied. The included studies were divided into "comparisons" according to the depth of sampling and dressing period of each medicament. Meta-analysis was performed using Stata software 10.0. The level of significance was set at 0.05. Results: Eighty-five studies were retrieved from databases and backward/forward searches. Fortyfive studies were considered as relevant (5 in vivo, 18 in vitro, 18 ex vivo, and 4 review articles). Nine studies were included for meta-analysis. Inter-observer agreement (Cohen kappa) was 0.93. The included studies were divided into 21 comparisons for meta-analysis. Chi-square test showed the comparisons were heterogeneous (p<0.001). Random effect model demonstrated no significant difference between CH/CHX mixture and CH alone in their effect on E. faecalis (p=0.115). Conclusions: According to the evidence available now, mixing CH with CHX does not significantly increase the antimicrobial activity of CH against E. faecalis. It appears that mixing CH with CHX does not improve its ex vivo antibacterial property as an intracanal medicament against E. faecalis. Further in vivo studies are necessary to confirm and correlate the findings of this study with the clinical outcomes.