Eficácia das manobras de desbridamento no preparo químico-mecânico quanto à desinfecção no terço apical em molares humanos / Efficacy of chemo-mechanical preparation debridement procedures in disinfection of the apical third of human molar root canals

Objetivo: Avaliar a eficácia das manobras de desbridamento no preparo químico-mecânico (PQM) quanto a limpeza e desinfecção no terço apical em molares humanos. Material e método: Cinquenta raízes mesiais de molares inferiores humanos com dois canais radiculares foram inoculadas com E. faecalis e distribuídas aleatoriamente em cinco grupos (n=10). O PQM foi realizado com o sistema Protaper associado ao desbridamento com as limas Kerr #10 (G1 e G3) e as limas Kerr #15 (G2 e G4). O G5 representou o controle positivo, o qual foi submetido apenas ao PQM, sem receber o desbridamento. Outra variável foi o uso da medicação intracanal (MIC) à base de hidróxido de cálcio (Calen), que foi aplicada aos grupos G3 e G4. A irrigação foi feita com hipoclorito de sódio 2,5% e EDTA 17%. A análise da ação antimicrobiana se deu através da contagem das unidades formadoras de colônias (UFC). Resultado: Foram aplicados o Teste Kruskal-Wallis (nas análises imediatas) e o Teste Mann-Whitney (nas análises mediatas), ambos com p=0,01. A análise imediata ao PQM apresentou-se sem diferença estatística entre os grupos (p=0,11). No G4 (#15 + MIC), os resultados das coletas mediatas foram estatisticamente significantes (p=0,01). Conclusão: O desbridamento com as limas Kerr #10 e #15 não apresentou diferença significativa quanto à redução das colônias de E. faecalis quando comparado ao grupo em que não se realizou o desbridamento. Nos espécimes em que se aplicou a MIC, o desbridamento com a lima Kerr #15 (G4) foi mais eficiente do que a lima Kerr #10 (G3) em reduzir as UFC.

Aim: The aim of this in vitro study was to evaluate the efficacy of chemo-mechanical preparation (CMP) debridement procedures in regard to cleansing and disinfection of the apical third of human molar canals using different protocols. Material and method: Fifty mesial roots of human mandibular molars containing two canals were inoculated with E. faecalis strains and randomly allocated to five groups (n=10). CMP was carried out with the rotatory Protaper system associated with Kerr files #10 (G1 and G3) and #15 (G2 and G4). G5, the positive control, was subjected to CMP without debridement. Another variable studied was the use of calcium hydroxide-based temporary intracanal medication (Calen) prior to the chemo-mechanical performed in the G3 and G4 groups. Irrigation was performed with 2.5% sodium hypoclorite and 17% EDTA. Antimicrobial activity was quantified by counting the number of colony-forming units (CFU). Result: Kruskal-Wallis was used for immediate analyses and Mann-Whitney for mediate analyses both with a stipulated value of significance of p=0.01. In the imediate analyses following CMP there were no significant differences among the groups (p=0.11). In the G4 (#15 + MIC) the results of the mediate collections were statistically significant (p=0.01). Conclusion: Debridement with #10 and #15 Kerr files did not produce significant differences in regard to reduction of E. faecalis when compared to the positive control. In samples where Calen intracanal medication was used debridement with #15 Kerr files was more efficient in reducing the number of CFUs than #10 Kerr files.

Prospecção de atividade inibitória da pasta de hidróxido de cálcio e acetazolamida sobre Enterococcus faecalis e Candida albicans / Antimicrobial effect of calcium hydroxide paste and acetazolamide against the Enterococcus faecalis and Candida albicans

Introdução: A medicação intracanal é fundamental para o tratamento de um dente avulsionado, sendo a pasta de hidróxido de cálcio comumente indicada. A acetazolamida é uma substância inibidora da anidrase carbônica e da reabsorção óssea, podendo ser sugerida como medicação intracanal em dentes avulsionados. Contudo, para que uma substância seja sugerida, estudos devem comprovar sua eficácia tanto in vitro como in vivo. Objetivo: Avaliar in vitro a ação antimicrobiana da pasta de hidróxido de cálcio e da acetazolamida, associadas a diferentes veículos, contra os micro-organismos Enterococcus faecalis e Candida albicans. Materiais e métodos: As formulações selecionadas foram: acetazolamida (pó) com soro fisiológico; acetazolamida (pó) com glicerina; acetazolamida e hidróxido de cálcio (pó) em porções iguais com soro fisiológico; acetazolamida e hidróxido de cálcio (pó) em porções iguais adicionando-se glicerina; acetazolamida (líquido) e hidróxido de cálcio (pó) com soro fisiológico. Como controle positivo foram utilizadas concentrações de clorexidina de 20%, 10%, 5%, 2,5%, 1,25% e 0,65% e como controle negativo a glicerina. O experimento foi realizado por teste de difusão em ágar. Resultados: Não houve inibição do crescimento das bactérias com os medicamentos utilizados, apenas com o controle positivo.Conclusão: As formulações de hidróxido de cálcio e acetazolamida não apresentaram atividade inibitóriacontra o E. faecalis e C. albicans.

Introduction: The intracanal medication is essential for the treatment of avulsed tooth, being the calcium hydroxide paste usually indicated. The acetazolamide is an inhibiting substance of carbonic anhydrase and the bone resorption, being suggested as intracanal medication in avulsed teeth. However, for this substance became an alternative as intracanal therapeutic agent, it must be tested in vitro and in vivo. Objective: To evaluate, in vitro, the antimicrobial action of calcium hydroxide paste and acetazolamide associated with different vehicles, against the Enterococcus faecalis and Candida albicans. Materials and methods: The experimental groups were: acetazolamide (powder) with physiological serum; acetazolamide (powder) with glycerin; acetazolamide and calcium hydroxide (powder) in equal portions with physiological serum; acetazolamide and calcium hydroxide (powder) in equal portions added with glycerin; acetazolamide (liquid) and calcium hydroxide (powder) with physiological serum. Clorexidine was used for positive control in concentrations of 20%, 10%, 5%, 2.5%, 1.25% and 0.65% and glycerin was used as negative control. The study was carried through by test of diffusion in agar. Results: No experimental groups showed inhibition of the bacterial growth, only inhibited by the positive control. Conclusion: The groups with calcium hydroxide and acetazolamide did not show antimicrobial activity against the E. faecalis and C. albicans.

Prokaryotic expression and purification of the efaA protein from Enterococus faecalis antigens / 中国人兽共患病学报

To prokaryotic express prokaryotically and to purify the efaA protein from Enterococus faecalis so as to provide the basis for the further study on the pathogenesis and clinical sero-diagnosis of endocarditis caused by E.faecalis, efaA gene of E.faecalis was amplified by PCR, the PCR-amplified product was digested with restriction enzymes and cloned into prokaryotic vector pET32a to construct the recombinant plasmid pET30a/efaA. This recombinant plasmid was confirmed by double enzyme digestion with BamhI and Xhol and then subjected to sequencing, and transformed to E.coli BL21 (DE3). Expression of the fusion protein was induced by IPTG, and analyzed by SDS-PAGE and Western blotting. The recombinant fusion protein was purified by His-binding affinity chromatography.It was shown that efaA gene of 943 bp in size was amplified from Enterococus faecalis and the recombinant plasmid pET30a,/ efaA was successfully constructed and expressed in E.coli BL21. The purified product was found to be 34 kDa in molecular weight as demonstrated by SDS-PAGE and Western blotting. It is evident that the efaA protein of E.faecalis can be successfully expressed and purified.

Effects of Enterococcus faecalis sonicated extracts on IL-2, IL-4 and TGF-beta1 production from human lymphocytes / 대한치과보존학회지

In order to examine the immunoresponse of host cells to Enterococcus faecalis, this in vitro study monitored the production of Interleukin-2 (IL-2), Interleukin-4 (IL-4) and Transforming growth factor-beta1 (TGF-beta1) in human lymphocytes. Lymphocytes were activated with PHA in the presence or abscence of sonicated extracts of E. Faecalis (SEF) and further incubated for 72 hours. The level of each cytokine was measured by ELISA. Data were analyzed with Kruskal-Wallis test and Mann-Whitney U test (P < 0.05). PHA-activated group did exhibit higher level of IL-2 and IL-4 than untreated control group. The levels of expression of both cytokines were significantly decreased following the treatment of high (25 microg/ml) and medium concentration (12.5 microg/ml) of SEF (P <0 .05) than those of PHA activated group. But low concentration (5 microg/ml) of SEF showed the similar level of IL-2 and IL-4 production as those of PHA activated group. TGF-beta1 was unaffected by SEF treatment. These results suggested that E. faecalis may suppress IL-2 and IL-4 production by lymphocytes and this could be one of possible factors why E. faecalis are found frequently in the teeth with failed endodontic treatment.