Effectiveness of ultrasonic activation associated to glycolic acid on smear layer removal, dentin structure and bond strength to root dentin

This study evaluated the effects of ultrasonic activation (US) associated to glycolic acid (GA) on smear layer, dentin structure and bond strength (BS) of filling/restorative material to root dentin. The roots were used for antimicrobial activity, dentin structure and BS evaluation, being distributed into seven groups, according to irrigation protocols: G1:DW+US; G2:17% EDTA; G3:QMix; G4:17% GA; G5:17% EDTA+US; G6:QMix+US; G7:17% GA+US. Scanning electronic microscopy, transmission electronic microscopy and push-out were performed, with specific statistical analysis for each evaluation. The highest smear layer removal occured in Groups 6 and 7 (p<0.05), and the largest collagen dispersion in Group 7, being similar to Group 2 and 5 (p>0.05). The highest BS of filling and restorative material occurred in Groups 6 and 7, and Groups 5, 6 and 7, respectively, being similars between them (p>0.05). The use of GA+US promoted effective smear layer removal and dentin structure preservation, improving the BS of filling/restorative material to root dentin.

Effect of edta and qmix ultrasonic activation on the reduction of microorganisms and endotoxins in ex vivo human root canals

Abstract The present study aimed to compare the effectiveness of QMiX and 17% EDTA associated to passive ultrasonic irrigation (PUI) or manual agitation (MA) on the reduction of E. faecalis, E. coli and LPS from root canals. Forty single rooted human teeth were randomly divided into four groups (n=10), according to the final irrigation protocol: EDTA+MA, QMiX+MA, EDTA+PUI, QMiX+PUI. Sample collections were obtained from the root canal content immediately before preparation (baseline-S1), after instrumentation (S2), after final irrigation protocol (S3) and 7 days after instrumentation and final irrigation (S4). The antimicrobial effectivity and on endotoxin content were analyzed by culture procedure (CFU/mL) and LAL assay (EU/mL), respectively. The results were statistically analyzed by Kruskal-Wallis and Friedman test (α=5%). QMiX+MA and QMiX+PUI reduced 100% of E. coli and E. faecalis bacteria and also prevented E. faecalisregrowth at S4. EDTA significantly reduced E. coli, but it was not effective in reducing E. faecalis. All protocols reduced EU/mL when compared to S1, however at S4 there was a significant reduction of EU/mL only in the QMiX+MA and QMiX+PUI groups in relation to S3 and S2, respectively. Final irrigation with QMiX associated with MA or PUI had superior antibacterial efficacy compared to EDTA, eliminating 100% of E. coli and E. faecalis strains. In addition, QMiX+PUI reduced 97.61% of the initial content of LPS.

Resumo O presente estudo objetivou comparar a eficácia do QMiX e do EDTA 17% associado à irrigação ultrassônica passiva (PUI) ou agitação manual (MA) na redução de E. faecalis, E. coli e LPS de canais radiculares. Quarenta dentes humanos unirradiculares foram divididos aleatoriamente em quatro grupos (n = 10), de acordo com o protocolo final de irrigação: EDTA+MA, QMiX+MA, EDTA+PUI, QMiX+PUI. Coletas das amostras foram obtidas a partir do conteúdo do canal radicular imediatamente antes do preparo (inicial-S1), após a instrumentação (S2), após o protocolo final de irrigação (S3) e 7 dias após a instrumentação e irrigação final (S4). A eficácia antimicrobiana e o conteúdo de endotoxina foram analisados ​​por procedimento de cultura (UFC/mL) e ensaio LAL (EU/mL), respectivamente. Os resultados foram analisados estatisticamente pelo teste de Kruskal-Wallis e Friedman (α = 5%). QMiX+MA e QMiX+PUI reduziram 100% das bactérias E. coli e E. faecalis e também preveniram a recolonização de E. faecalis em S4. O EDTA reduziu significativamente E. coli, mas não foi eficaz na redução de E. faecalis. Todos os protocolos reduziram EU/mL quando comparados com S1, no entanto, no S4 houve uma redução significativa de EU/mL apenas nos grupos QMiX+MA e QMiX+PUI em relação a S3 e S2, respectivamente. A irrigação final com QMiX associada a MA ou PUI apresentou eficácia antibacteriana superior em relação ao EDTA, eliminando 100% das cepas de E. coli e E. faecalis. Além disso, QMiX+PUI reduziu 97,61% do conteúdo inicial de LPS.

The effect of different final intracanal irrigants on the bond strength of silicone-based sealer to root canal walls / 天津医药

Objective To evaluate the bond strength of GuttaFlow sealers to root canal walls after final rinse with two novel fi nal irrigation regimens, QMiX and 17%EDTA+0.2%Cetrimide (CTR). Methods Thirty single-canal teeth were prepared chemomechanically using 5.25% sodium hypochlorite (NaOCl) as root canal irrigants. The teeth were then randomly distributed into three groups(n=10)according to the final irrigation protocol:QMiX group,17% EDTA followed by CTR group and control group(normal saline,NS).After the filling with GuttaFlow using a lentulo spiral,the roots were transversally sectioned to obtain 2 mm thick dentinal slices.Then a push-out bond strength test was carried out,and failure mode was determined at×24 magnification.Results The push-out bond strength was significantly higher in QMiX group than that of EDTA+CTR group and NS group(P<0.05),and no significant difference was observed between EDTA+CTR and NS groups(P>0.05).The failure patterns were mainly mixed.Conclusion The QMiX,as the final irrigant,can improve the bond strength of silicone-based sealer GuttaFlow.

Research progress on QMix properties in root canal irrigation / 华西口腔医学杂志

Mechanical instrumentation preparation alone is insufficient to completely remove root canal infection, and chemical irrigation is essential to eliminate infected remnants. An ideal root canal irrigant should completely remove the smear layer, lubricate the root canal, efficiently kill bacteria, induce mild or no inflammatory response in the tissues, and avoid damaging the dentin structure. However, a commercial irrigant that meets all these requirements is currently lacking. QMix is a root canal irrigation mixture of ethylenediamine tetraacetic acid (EDTA), chlorhexidine (CHX) and surfactant. This mixture can remove the smear layer efficiently, and it possesses strong antibacterial effect and good biocompatibility with minimal cytotoxicity. Furthermore, the influence of QMix on the color and micro-hardness of dentin is low, and it can improve the wettability of root canal sealant without affecting its adhesive properties. This review compares the efficiencies of QMix with other irrigants (sodium hypochlorite, CHX, EDTA, SmearClear, and MTAD) in term of smear layer removal, dentine and root canal sealing, cell cytotoxicity, and bacterial growth inhibition.

Comparative Evaluation of Smear Layer Removal Efficacy Using QMix 2in1, Chitosan, Smear Clear and Glyde.

Aim and Objective: The effects of four endodontic irrigants and on a smear layer created by hand and rotary instrumentation were evaluated in vitro in the middle and apical thirds of root canals. Materials and Methods: Forty eight mature extracted mandibular premolar teeth with a single root canal and a closed apex were distributed randomly into four groups of 12 teeth each. Whilst cleaning and shaping up to size F5 using Protaper Universal System, the root canals were irrigated with 3 mL of 5.25% NaOCl, between each file size. Group 1 (G1) were irrigated with a final flush of QMix 2in1. The teeth in group 2 (G2) were irrigated with a final flush of 0.2%Chitosan, group 3 (G3) with Smear Clear and group 4 (G4) with Glyde. The teeth were split longitudinally and prepared for examination by scanning electron microscopy. Results: Specimens irrigated with a final flush of Glyde (G4) or 0.2%Chitosan (G2) were cleaner than with QMix and Smear Clear, showing very clean root canal surfaces in the middle one-third but in the apical one-third the smear layer was not completely removed, especially at the openings of the dentinal tubules. Statistical analysis showed no significant difference in the cleanliness of root canal wall between G1, G2, G3 and G4. Conclusion: Irrigation with QMix 2in1, Smear Clear, 0.2%Chitosan, and Glyde and 6% did not remove all the smear layer from the root canal system. All these irrigants showed less effectiveness in removal of smear layer from apical 3rd. Glyde showed maximum efficacy in removal of removal of smear layer followed by 0.2%Chitosan, Smear Clear and then QMix 2in1.

Eficácia de diferentes substâncias químicas auxiliares na rápida desinfecção de cones de guta-percha ? estudo in vitro / Effectiveness of different auxiliary chemical substances in the rapid disinfection of gutta-percha points ? an in vitro study

Objetivo: avaliar in vitro a eficácia de diferentes substâncias químicas auxiliares utilizadas para promover a descontaminação de cones de guta-percha, que estão contaminados com diferentes microorganismos. Materiais e método: cepas Enterococcus faecalis, Candida albicans e Staphylococcus aureus foram os microrganismos testados. Os 72 cones de guta-percha foram divididos em três grupos de 24 cones, e foram transferidas individualmente em três tubos, contendo 5 ml de cada suspensão bacteriana, durante 1 hora. Os 24 cones de guta-percha de cada estirpe bacteriana foram distribuídos aleatoriamente em seis grupos (n = 4), de acordo com a substância química auxiliar e com o tempo de descontaminação, como segue: G1 (DW) - água destilada; G2 (NaOCl) - hipoclorito de sódio a 2,5%; G3 (Ca (OCl) 2) - 2,5% de hipoclorito de cálcio; G4 (CHX) - clorexidina gel 2%; G5 (QMix) - QMix e G6 (GSE) - Extrato de Semente de Uva 6,5%, em quatro períodos de avaliação, que foram 30, 60, 90 e 120 segundos. Depois de protocolos de desinfecção das pontas de guta-percha, foram transferidos para tubos contendo 450 mL de solução salina estéril, homogeneizada e diluída. Alíquotas de 100 µl da solução e as diluições foram cultivadas em duplicado em placas de ágar contendo o sangue. Esse material foi incubado durante 48 horas a 37 °C de temperatura. Depois disso, a contagem do número de unidades formadoras de colônias (CFU / mL) foi realizada. Resultados: os grupos 2 (NaOCl), 3 (Ca (OCl) 2), 4 (CHX) e 5 (QMix) não apresentaram crescimento bacteriano de microrganismos testados em todos os períodos de observação, sendo estatisticamente diferente de todos os outros grupos (p <0,05). O Grupo 6 (GSE) mostrou a melhor atividade antimicrobiana contra albicans Enterococcus faecalis e Candida Staphylococcus aureus em relação ao grupo 1 (DW), sendo estatisticamente diferente (p <0,05). Conclusão: hipoclorito de sódio a 2,5%, 2,5% de hipoclorito de cálcio, 2% de gel de clorexidina e QMix podem ser uti-lizados como agentes eficazes na desinfecção rápida de cones de guta-percha contaminados após 30 segundos de utilização dessas substâncias.