Effect of Chelating Agents on Push-Out Bond Strength of NeoMTA Plus to Root Canal Dentin

ABSTRACT Objective To evaluate and compare the effect of 17% Ethylenediaminetetraacetic Acid (EDTA), 9% Etidronic acid (HEDP), and 7% Maleic acid (MA) on the push-out bond strength of NeoMTA Plus sealer to the coronal, middle, and apical thirds of root canal dentin. Material and Methods Forty single-rooted human maxillary central incisors were selected and decoronated to 12 mm long root fragments. Working length was established and root canals were then enlarged up to rotary Protaper F3. After each instrumentation, the root canal was irrigated with 2.5% NaOCl. For the final irrigation regimen, the specimens were divided into 4 groups (n=10) and treated with EDTA, HEDP, MA or Saline. Root canals were coated with NeoMTA Plus sealer, and obturation was done with single cone obturation technique. Subsequently, three horizontal sections were taken from the coronal, middle and apical thirds of each specimen, and POBS was measured using a universal testing machine. The type of bond failures was assessed under a stereomicroscope. Statistical analysis was done with One-way ANOVA with Tukey's Post hoc analysis. Results MA and EDTA showed the highest POBS. There was no significant difference in bond strength between MA and EDTA (p>0.05). HEDP and Saline showed lower POBS. Among all the four groups, the coronal third showed the highest values, followed by middle and apical thirds. Conclusion The type of chelating agent used during the root canal treatment significantly affects the bond strength of NeoMTA Plus to the root canal dentin.

Eficácia do etidronato na remoção da smear layer dos canais radiculares: um estudo com microscopia eletrônica de varredura / Effectiveness of etidronate in root canal smear layer removal: A study with scanning electron microscopy

Avaliar, por microscopia eletrônica de varredura (MEV), o efeito do uso individual e combinado do etidronato 18% (HEBP) na remoção da smear layer do canal radicular. Métodos: Trinta dentes humanos unirradiculares foram utilizados. As raízes foram preparadas com instrumentos rotatórios do Sistema ProTaper Universal e divididas aleatoriamente em três grupos, de acordo com o protocolo de irrigação empregado: G1 = hipoclorito de sódio 2,5% (NaOCl) e ácido etilenodiaminotetracético 17% (EDTA); G2 = NaOCl 2,5% e HEBP 18%; e G3 = NaOCl 2,5% + HEBP 18%, misturados em partes iguais. As raízes foram seccionadas longitudinalmente e metalizadas, para análise em MEV. As fotomicrografias obtidas dos terços cervical, médio e apical foram avaliadas por três examinadores calibrados, que atribuíram escores de 1 a 5 às imagens. Os grupos experimentais foram comparados usando o teste de Kruskal-Wallis e o teste de Student-New- man-Keuls. Os terços radiculares foram comparados pelo teste de Friedman. O nível de significância foi estabelecido em 5%. Resultados: A capacidade de remoção da smear layer com NaOCl 2,5% e 18% HEBP (G2) foi semelhante à obtida com NaOCl 2,5% e EDTA 17% (G1) no terço médio e cervical da raiz; o nível de limpeza do terço apical foi semelhante, independentemente do protocolo de irrigação utilizado. Conclusão: HEBP é uma solução promissora para uso em tratamentos endodônticos (AU).

Introduction: We evaluated the effect of individual and combined use of 18% etidronate (HEBP) in root canal smear layer removal using scanning electron microscopy (SEM). Methods: Thirty human single-rooted teeth were used. The roots were prepared with ProTaper Universal System rotary files and randomly divided into three groups according to the irrigation protocol used. G1: 2.5% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA); G2: 2.5% NaOCl and 18% HEBP; and G3: 2.5% NaOCl + HEBP 18%, mixed in equal parts. The roots were sectioned longitudinally and metallized for SEM analysis. The photomicrographs obtained from the cervical, middle, and apical thirds were evaluated by three calibrated examiners, who assigned scores from 1 to 5 to the images. The experimental groups were compared using the Kruskal-Wallis test and the Student-Newman-Keuls test. Root thirds were compared by the Friedman test. The level of significance was set at 5%. Results: The capacity for removal of the smear layer by 2.5% NaOCl and 18% HEBP (G2) was similar to that achieved with 2.5% NaOCl and 17% EDTA (G1) in the cervical and middle thirds of the root; the cleansing level of the apical third was similar, regardless of the irrigation protocol used. Conclusion: HEBP is a promising solution for use in endodontic treatments (AU).

Avaliação da expressão de citocinas pró e anti-inflamatórias após estímulo celular com diferentes agentes irrigantes / Evaluation of the expression of pro and anti-inflammatory cytokines after cellular stimulation with different irrigating agents

O objetivo do trabalho foi investigar o efeito de diferentes soluções químicas auxiliares, em concentrações subcitotóxicas, na expressão de citocinas pró e anti-inflamatórias, quando em contato com células da linhagem de linfoma humano, diferenciadas em macrófagos, human macrophage-like (U937), através da adição de 125ng/mL de PMA. As concentrações, citotóxica e subcitotóxica, de cada solução, foram determinadas de acordo com padrão ISO, utilizando-se fibroblastos de camundongos (L929). As células L929 foram cultivadas em meio MEM completo e mantidas em placas de 96 poços. As células foram então colocadas em contato com as diluições das soluções químicas auxiliares (a partir das concentrações recomendadas para uso, NaOCL 5,25%; CHX 2%; Quitosana 0,2%; HEBP 18%; GSE de Vitis vinífera, 6,5%), por 24 horas a 37ºC em estufa de CO2. Em seguida, o meio de cultivo contendo 1mg/mL de MTT foi adicionado aos poços em triplicata, para avaliação da viabilidade celular e determinação das concentrações citotóxicas (30% de morte das células L929) e subcitotóxicas (15% de morte) por regressão linear por meio do programa GraphPad Prism versão 6.0. As concentrações subcitotóxicas foram colocadas em contato com as células human macrophage-like (U937) por 60 min. Os sobrenadantes da pré-incubação (controles sem substâncias químicas auxiliares), e incubação com as soluções químicas auxiliares em meio DMEM completo foram congelados em freezer ultrafrio (­ 80ºC) e avaliados para as concentrações de dezessete citocinas através do kit Bio-Plex Pro Human Th17 Cytokine Panel® pelo método Luminex®. Foi possível obter valores de expressão de 7 citocinas pró-inflamatórias: IL-1ß, TNFα, IL-6, IL-17A, IL-17F, IL-22 e IL-23. As substâncias com maior atividade citotóxica (padrão ISO para morte celular) foram em ordem de grandeza, a quitosana, a CHX, o NaOCl, o HEBP e o GSE de Vitis vinifera. As concentrações subcitotóxicas das soluções químicas auxiliares, CHX e NaOCl, induziram ao aumento da maioria das citocinas pró-inflamatórias, exceto para a IL-6. Quanto a IL-1ß, a quitosana e a CHX, estas foram as que mais induziram a expressão pelas células U937 (P<0,05),enquanto o NaOCl induziu maior expressão de TNFα (P>0,05). Dentre as citocinas relacionadas ao fenótipo Th17, a CHX foi a que mais induziu a expressão de IL-17A (P<0,05), IL-17F e IL-23, seguido do NaOCl(P<0,05). O NaOCl induziu maior expressão de IL22 seguido da CHX (p<0,05). Quanto a IL-6, todas as substâncias modularam a sua expressão pelas células U937(p>0.05). O HEBP atuou como um excelente modulador da expressão de citocinas pró-inflamatórias, induzindo a redução da expressão de todas as citocinas testadas (P<0,05). O GSE de Vitis vinifera, apesar de ser o menos citotóxico não apresentou diferença estatística para o controle em nenhuma das situações avaliadas, exceto para a redução da IL-6 (assim como o HEBP e a quitosana) (p<0,05). A quitosana comportou-se de forma similar ao GSE de Vitis vinífera (p>0,05) exceto para a IL-1ß. Conforme observado, as substâncias químicas auxiliares são capazes de induzir a expressão de citocinas pró-inflamatórias diversas. O HEBP foi o agente químico que melhor modulou a expressão de citocinas pró-inflamatórias.

The aim of this investigation was to analyze the effect of different chemical endodontic solutions, in subcytotoxic concentrations, on the expression of pro and anti-inflammatory cytokines when in contact with human lymphoma lineage differentiated into human macrophages, human macrophage-like (U937), by the addition of 125ng/ml PMA. The cytotoxic and subcytotoxic concentrations of each solution were determined according to ISO standard using mouse fibroblasts (L929). L929 cells were cultured in complete MEM medium and maintained in 96-well plates. Dilutions of the auxiliary chemical solutions, from the recommended concentrations for use: NaOCL 5,25%; CHX 2%; Chitosan 0.2%; Etidronic acid 18% and Grape seed extract, Vitis vinifera, 6.5%, were carried out in complete MEM medium, and placed in contact with the cells for 24 hours at 37ºC in CO2 cell incubator, in triplicate. Thereafter, the culture medium containing 1 mg/mL MTT was added to the wells. Cytotoxic concentrations (30% death of L929 cells) and subcytotoxic (15% death) were determined by linear regression using GraphPad Prism version 6.0. Subcytotoxic concentrations were obtained in complete DMEM medium and maintained in contact for 60 min. with U937 cells. Controls without chemical substances were also performed. Supernatants from the pre-incubation, incubation with the chemical solutions and complete DMEM were removed, frozen in ultra-cold freezer (-80ºC) and evaluated for the concentrations of 17 cytokines through the Bio-Plex Pro Human Th17 Cytokine Panel® kit by Luminex®. The substances with higher cytotoxic activity were in order of magnitude: chitosan, CHX, NaOCl, etidronic acid and Vitis vinifera extract. The values of 7 pro-inflammatory cytokines: IL-1ß, TNFα, IL-6, IL-17A, IL-17F, IL-22 and IL-23 were obtained. Subcytotoxic concentrations of the irrigant agents (chlorhexidine and NaOCl) generally induced the increase of most pro-inflammatory cytokines, except for IL-6. Chitosan and CHX were the agents that most induced the expression of IL-1ß by U937 cells, whereas NaOCl induced higher TNFα expression (P> 0,05). Among the cytokines related to the Th17 phenotype, CHX was the agent that induced the highest expression of IL-17A (P <0,05), IL-17F and IL-23, followed by NaOCl (P<0,05). NaOCl induced the highest expression of IL22 followed by CHX. All of the substances modulated the expression of IL-6 by U937 cells (P >0,05). HEBP was an excellent modulator of the expression of pro-inflammatory cytokines, inducing the reduction of the expression of all cytokines tested. Vitis vinifera extract, despite being the least cytotoxic agent, did not present statistical differences compared to the control for any of the evaluated cytokines, except for the reduction of IL-6 (as well as etidronic acid and chitosan) (P<0,05). Chitosan, except for IL-1 ß, was very similar to the Vitis vinifera (P>0,05) extract. As observed, the auxiliary substances (especially the irrigants) are capable of inducing the expression of various pro-inflammatory cytokines. Etidronic acid was the chemical that modulated the expression of pro-inflammatory cytokines.

Effects of different irrigation regimes in physico-chemical properties of dentin and consequences of changes in the adhesion of microorganisms and AH Plus sealer / Efeitos de diferentes regimes de irrigação nas propriedades físicoquímicas da dentina e consequências das alterações na adesão de microrganismos e do cimento endodôntico AH Plus

Besides of the desired effects, the chemical solutions used to assist the endodontic instruments in the cleanliness and disinfection of the root canal system can also cause changes in the physicochemical properties of dentin, and consequently affect the adhesion of endodontic sealers and microorganisms to the root canal walls. However, the effects of new irrigators and irrigation protocols remain unknown. The objectives of this thesis were to verify the alterations in the properties of some irrigants when used combined in mixtures, to define the time necessary for the smear layer removal by a new irrigant, to determine the organic matter dissolution capacity and the effects in the physicochemical properties of dentin of some irrigation solutions and protocols, and to evaluate the adhesion of microorganisms and AH Plus sealer to dentin after its submission to different irrigation sequences. In all experiments with dentin, the samples used were obtained from bovine teeth. In the analysis performed in this thesis, the following solutions were tested isolated and combined in different irrigation protocols: saline solution (control), sodium hypochlorite (NaOCl), trisodium (EDTAHNa3), alkaline ethylenediaminetetraacetic acid tetrasodium (EDTANa4), chlorhexidine (CHX), peracetic acid (PAA), and etidronic acid (HEDP). The EDTAHNa3 and EDTANa4 were tested in relation to their effects on the free chlorine content of NaOCl. The solutions were mixed in a 1:1 ratio and the iodometric titration of the mixtures performed in different time intervals. The time necessary for smear layer removal from dentin samples by solutions of EDTAHNa3 and different concentrations of EDTANa4 isolated and mixed with NaOCl was determined with the aid of the scanning electron microscope (SEM). The capacity of NaOCl to dissolve organic matter was determined by weighting fragments of bovine muscle before and after immersion in solutions of 1%, 2.5%, and 5% of NaOCl in different periods of time. Also, the effects of EDTAHNa3, EDTANa4 and HEDP on the organic matter dissolution by NaOCl were evaluated. The alterations produced by all solutions isolated and some irrigation protocols in the organic and inorganic components of the dentin surface were analysed by the attenuated total reflectance of Fourier transform infrared spectroscopy (ATR-FTIR) technique. Absorbance spectra were collected from the dentin surface before and after immersion of samples in the irrigants and the ratios of the amide III/phosphate and carbonate/phosphate bands were calculated. To quantify the adhesion of CHX to mineralized dentin and to dentin demineralized by different irrigation protocols, the areas of the band associated with CHX with the peak in 1492 cm−1 were determined in spectra obtained by ATR-FTIR. The effects of different irrigation protocols in the roughness and wettability of dentin surface were measured with a benchtop roughness tester and the sessile drop technique, respectively. For the assays of microorganisms' adhesion, samples were prepared and treated the same way and with the same irrigation protocols used in the roughness and wettability tests. Following, Candida albicans and Enterococcus faecalis were maintained in contact with the dentin for 2 hours and the samples were analyzed on the confocal laser scanning microscope (CLSM). Tests of push-out were performed to determine the impact of different irrigation protocols on the dentin bonding strength of AH Plus sealer over time. Canals of bovine incisors teeth were instrumented, irrigated and following obturated using only the sealer AH Plus. Half of the samples were submitted to pushout assessment 7 days after the obturation and the other half 20 months later. The results of the experiments showed that the EDTAHNa3 caused an almost complete and immediate loss of free available chlorine from NaOCl, whilst EDTANa4 promoted a slow and concentration-dependent decline. The smear layer was removed only by decalcifying solutions and in about 1 min by the 17% EDTAHNa3 and 5 min by the EDTANa4, both isolated or mixed with NaOCl. The increase in NaOCl concentration and contact time with the samples intensified the dissolution of organic matter. The mixtures of NaOCl with EDTANa4 and HEDP were able to dissolve the fragments of bovine muscle over-time, however, the EDTAHNa3 strongly affected the NaOCl dissolution capacity when they were mixed. The results of ATR-FTIR experiments showed that the increase in the NaOCl concentration intensified the deproteination of the dentin collagen with a reduction in the amide III/phosphate ratio. For the same decalcifying agent, the higher the concentration and immersion time the greater the removal of phosphate, exposure of the collagen matrix and consequently the increases in amide III/phosphate ratio. The PAA caused greater increases in amide III/phosphate ratio, followed by EDTAHNa3, EDTANa4 and HEDP and this order was maintained in the protocols in which NaOCl was used before the decalcifying agents. NaOCl required approximately 0.5 min to deproteinate the collagen matrix exposed after phosphate removal by EDTAHNa3 and PAA. The carbonate/phosphate ratio decreased after 30 s of samples immersion in solutions of NaOCl at 1%, 2.5% and 5% with no more alterations over time. The carbonate of the dentine was removed faster than phosphate by all decalcifying agents employed alone and in the irrigation protocols in which the use of the NaOCl was followed by the use of the EDTAHNa3, PAA and HEDP. For irrigation protocols that associate NaOCl with chelating solutions, the last irrigant used defined the final dentine amide III/phosphate and carbonate/phosphate ratios. For the ATR-FTIR analysis of CHX adhesion, the results showed that the adsorption of this irrigant to the dentin was potentiated when chelating agents were used prior to the CHX. In relation to the experiments of surface roughness, the saline solution, NaOCl, HEDP and CHX did not alter the roughness of the dentin, but EDTAHNa3 and PAA increased it. The wettability of the surface increased after the use of all irrigants, being the HEDP to cause the greater increases. In the assays of microorganisms' adhesion, the smear layer and collagen exposed by the chelating agents favored the adhesion of E. faecalis. The C. albicans adhesion was major in surfaces with smear layer and more mineral. The use of CHX as the final irrigant reduced the adhesion of both microorganisms. The wettability did not influence the microorganisms' adhesion, while increases in roughness seems to potentiate the adherence of E. faecalis. The experiments of bond strength of AH Plus to the dentin showed that the irrigation with NaOCl and mixture of NaOCl + EDTANa4 produced the lowest push-out bond strength values in 7 days compared to NaOCl + EDTAHNa3, NaOCl + EDTAHNa3 + NaOCl, NaOCl + EDTAHNa3 + CHX and the mixture of NaOCl + HEDP. After 20 months the lowest values were obtained in the groups irrigated with NaOCl and NaOCl + EDTAHNa3. The groups of NaOCl + EDTAHNa3 + NaOCl, mixture NaOCl + HEDP, and mixture NaOCl + EDTANa4 presented values of push-out bond strength in 20 months similar to the values in 7 days. It was possible to conclude that the irrigation solutions tested in this study have different effects in the organic and inorganic matter and some of them can affect the action of each other when mixed. Independent of being used isolated or combined in irrigation protocols, these irrigants cause modifications in the dentin physicochemical properties that influence the adhesion of AH Plus sealer in short and long term and the microorganisms' adherence to the surface in cases of recontaminations.(AU)

Além dos efeitos desejados, as soluções químicas utilizadas para auxiliar os instrumentos endodônticos na limpeza e desinfecção do sistema radiculares podem causar alterações nas propriedades físico-químicas da dentina e consequentemente afetar a adesão de cimentos endodônticos e microrganismos às paredes do canal radicular. Contudo, os efeitos de novos irrigantes e protocolos de irrigação ainda são desconhecidos. Os objetivos desta tese foram verificar as alterações nas propriedades de alguns irrigantes quando utilizados combinados em misturas, definir o tempo necessário para a remoção da camada de smear layer por um novo irrigante, determinar a capacidade de dissolução de matéria orgânica e os efeitos de algumas soluções e protocolos de irrigação nas propriedades físico-químicas de dentina e avaliar a adesão de microrganismos e cimento AH Plus à dentina após a submissão desta a diferentes sequências de irrigação. Em todos os experimentos com dentina as amostras utilizadas foram obtidas a partir de dentes bovinos. Nas análise realizadas nesta tese as seguintes soluções foram testadas isoladas e combinadas em diferentes protocolos de irrigação: solução salina (controle), hipoclorito de sódio (NaOCl), ácido etilenodiaminotetraacético trisódico (EDTAHNa3), ácido etilenodiaminotetracético tetrassódico alcalino (EDTANa4), clorexidina (CHX), ácido peracético (PAA) e ácido etidrônico (HEDP). O EDTAHNa3 e o EDTANa4 foram testados em relação aos seus efeitos sobre o teor de cloro livre do NaOCl. As soluções foram misturadas em uma proporção de 1:1 e a titulação iodométrica das misturas realizada em diferentes intervalos de tempo. O tempo necessário para a remoção da smear layer de amostras de dentina pela solução de EDTAHNa3 a 17% e diferentes concentrações de EDTANa4 isoladas e misturadas com NaOCl foi determinado com o auxílio do microscópio eletrônico de varredura (SEM). A capacidade de dissolução de matéria orgânica pelo NaOCl foi determinada pesando fragmentos de músculo bovino antes e depois da imersão em soluções de 1%, 2,5% e 5% de NaOCl em diferentes períodos de tempo. Além disso, os efeitos do EDTAHNa3, EDTANa4 e HEDP na dissolução de matéria orgânica pelo NaOCl foram avaliados. As alterações produzidas por todas as soluções isoladas e alguns protocolos de irrigação nos componentes orgânicos e inorgânicos da superfície da dentina foram analisadas pela técnica de reflexão total atenuada em espectroscopia no infravermelho por transformação de Fourier (ATRFTIR). Espectros de absorbância foram coletados da superfície da dentina antes e após a imersão das amostras nos irrigantes, e foram calculadas as razões das bandas de amida III/fosfato e carbonato/fosfato. Para quantificar a adesão da CHX à dentina mineralizada e à dentina desmineralizada por diferentes protocolos de irrigação, foram determinadas as áreas da banda associada a CHX com pico em 1492 cm−1 em espectros obtidos por ATR-FTIR. Os efeitos de diferentes protocolos de irrigação na rugosidade e molhabilidade da superfície da dentina foram medidos com um rugosímetro de bancada e a técnica de gota séssil, respectivamente. Para os ensaios de adesão de microrganismos, amostras foram preparadas e tratadas da mesma maneira e com os mesmos protocolos de irrigação utilizados nos testes de rugosidade e molhabilidade. Em seguida, Candida albicans e Enterococcus faecalis foram mantidos em contato com a dentina por 2 horas e as amostras foram analisadas no microscópio confocal de varredura laser (CLSM). Testes de push-out foram realizados para determinar o impacto de diferentes protocolos de irrigação na resistência de união à dentina do cimento AH Plus ao longo do tempo. Canais de dentes incisivos de bovinos foram instrumentados, irrigados e em seguida obturados utilizando apenas o cimento AH Plus. Metade das amostras foi submetida a avaliação de push-out 7 dias após a obturação e a outra metade após 20 meses. Os resultados dos experimentos mostraram que o EDTAHNa3 causou uma perda quase completa e imediata do cloro livre do NaOCl, enquanto o EDTANa4 promoveu um declínio lento e concentração dependente. A smear layer foi removida apenas por soluções descalcificantes e em cerca de 1 min pelo EDTAHNa3 a 17% e em 5 min pelo EDTANa4, tanto isolados ou misturados com o NaOCl. O aumento da concentração de NaOCl e do tempo de contato com os fragmentos de músculo bovino intensificou a dissolução da matéria orgânica. As misturas de NaOCl com EDTANa4 e HEDP foram capazes de dissolver as amostras de músculo ao longo do tempo, no entanto, o EDTAHNa3 afetou fortemente a capacidade de dissolução do NaOCl quando eles foram misturados. Os resultados dos experimentos com ATR-FTIR mostraram que o aumento da concentração do NaOCl intensificou a desproteinização do colágeno da dentina com redução da relação amida III/fosfato. Para o mesmo agente de descalcificação, quanto maior a concentração e o tempo de imersão, maior a remoção de fosfato, exposição da matriz de colágeno e consequentemente o aumento da proporção amida III/fosfato. O PAA causou os maiores aumentos na relação amida III/fosfato, seguido de EDTAHNa3, EDTANa4 e HEDP e esta ordem foi mantida nos protocolos em que o NaOCl foi usado antes dos agentes descalcificantes. O NaOCl necessitou aproximadamente 0,5 min para desproteinizar a matriz de colágeno exposta após a remoção de fosfato pelo EDTAHNa3 e o PAA. A relação carbonato/fosfato diminuiu após 30 s de imersão das amostras em soluções de NaOCl a 1%, 2,5% e 5%, sem mais alterações ao longo do tempo. O carbonato da dentina foi removido mais rápido do que o fosfato por todos os agentes descalcificantes empregados sozinhos e nos protocolos de irrigação em que o uso do NaOCl foi seguido pelo uso do EDTAHNa3, PAA e HEDP. Para os protocolos de irrigação que associam o NaOCl com soluções quelantes, o último irrigante utilizado definiu as proporções finais de amida II/fosfato e carbonato/fosfato da dentina. Para as análises da adesão da CHX em ATR-FTIR, os resultados mostraram que a adsorção deste irrigante à dentina foi potencializada quando agentes quelantes foram utilizados antes da CHX. Em relação aos experimentos de rugosidade da superfície, a solução salina, o NaOCl, o HEDP e a CHX não alteraram a rugosidade da dentina, mas o EDTAHNa3 e o PAA a aumentaram. A molhabilidade da superfície aumentou após o uso de todos os irrigantes, sendo que o HEDP causou os maiores aumentos. Nos ensaios de adesão dos microrganismos, a smear layer e o colágeno exposto pelos agentes quelantes favoreceram a adesão de E. faecalis. A adesão da C. albicans foi maior em superfícies com smear layer ou mais mineral. O uso de CHX como irrigante final reduziu a adesão de ambos os microrganismos. A molhabilidade não influenciou a adesão dos microrganismos, enquanto o aumento da rugosidade parece potencializar a adesão do E. faecalis. Os experimentos de resistência de união do AH Plus à dentina mostraram que a irrigação com NaOCl e a mistura de NaOCl + EDTANa4 produziram valores de resistência de união em 7 dias mais baixos em comparação com NaOCl + EDTAHNa3, NaOCl + EDTAHNa3 + NaOCl, NaOCl + EDTAHNa3 + CHX e a mistura de NaOCl + HEDP. Após 20 meses, os valores mais baixos foram obtidos nos grupos irrigados com NaOCl e NaOCl + EDTAHNa3. Os grupos de NaOCl + EDTAHNa3 + NaOCl, mistura de NaOCl + HEDP e mistura de NaOCl + EDTANa4 apresentaram valores de força de união por push-out em 20 meses semelhante aos valores em 7 dias. Foi possível concluir que as soluções de irrigação testadas neste estudo têm diferentes efeitos na matéria orgânica e inorgânica e elas podem afetar as ações umas das outras quando misturadas. Independentemente de serem utilizadas isoladas ou combinadas em protocolos de irrigação, os irrigantes causam modificações nas propriedades físico-químicas dentinárias que influenciam na adesão do cimento AH Plus a curto e longo prazo e na adesão de microrganismos à superfície em casos de recontaminação.(AU)

The Efficacy of Bisphosphonates for Prevention of Osteoporotic Fracture: An Update Meta-analysis

BACKGROUND: The efficacy of bisphosphonates for osteoporotic fracture has been consistently reported in recent randomized controlled trials (RCTs) enrolling hundreds of patients. The objective of this study was to update knowledge on the efficacy of available bisphosphonates in the prevention of vertebral and non-vertebral fractures. METHODS: An approach “using systematic reviews” on PubMed and Cochrane Library was taken. Twenty-four RCTs investigating the effects of bisphosphonates for the prevention of osteoporotic fracture were included in final analysis. A pairwise meta-analysis was conducted with a random effects model. Subgroup analysis was performed according to the type of bisphosphonate. RESULTS: The use of bisphosphonate decrease the risk of overall osteoporotic fracture (odds ratio [OR] 0.62; P<0.001), vertebral fracture (OR 0.55; P<0.001) and non-vertebral fracture (OR 0.73; P<0.001). Subgroup analysis indicated that zoledronic acid showed the lowest risk reduction (OR 0.61; P<0.001) for overall osteoporotic fractures but no significance was observed for etidronate (OR 0.34; P=0.127). CONCLUSIONS: This update meta-analysis re-confirmed that bisphosphonate use can effectively reduce the risk of osteoporotic fracture. However, there is a lack of evidence regarding etidronate for the prevention of osteoporotic fracture.

Estudio de la actividad antimicrobiana de una crema dental en gel con EDS frente a Streptococcus mutans y Actinobacillus actinomycetemcomitans / A study of the antimicrobial activity of a EDS-containing dental gel against Streptococcus mutans and Actinobacillus actinomycetemcomitans

Determinar la actividad antimicrobiana de la pasta en gel de dientes contra dos microorganismos: mutans Streptococccus y Actinobacillus actinomycetemcomitans...

Effect of endodontic chelating solutions on the bond strength of endodontic sealers

The purpose of this in vitro study was to evaluate the effect of various chelating solutions on the radicular push-out bond strength of calcium silicate-based and resin-based root canal sealers. Root canals of freshly-extracted single-rooted teeth (n = 80) were instrumented by using rotary instruments. The specimens were randomly divided into 4 groups according to the chelating solutions being tested: (1) 17% ethylenediaminetetraacetic acid (EDTA); (2) 9% etidronic acid; (3) 1% peracetic acid (PAA); and (4) distilled water (control). In each group, the roots were further assigned into 2 subgroups according to the sealer used: (1) an epoxy resin-based sealer (AH Plus) and (2) a calcium silicate-based sealer (iRoot SP). Four 1 mm-thick sections were obtained from the coronal aspect of each root (n = 40 slices/group). Push-out bond strength test was performed at a crosshead speed of 1 mm/min., and the bond strength data were analyzed statistically with two-way analysis of variance (ANOVA) with Bonferroni’s post hoc test (p < 0.05). Failure modes were assessed quantitatively under a stereomicroscope. Irrespective of the irrigation regimens, iRoot SP exhibited significantly higher push-out bond strength values than AH Plus (p < 0.05). For both the sealers, the use of chelating solutions increased the bond strength, but to levels that were not significantly greater than their respective controls (p > 0.05). iRoot SP showed higher resistance to dislocation than AH Plus. Final irrigation with 17% EDTA, 9% Etidronic acid, and 1% PAA did not improve the bond strength of AH Plus and iRoot SP to radicular dentin.

Role of Triticum aestivum aqueous extract in glucocorticoid induced osteoporosis in rats.

Administration of aqueous extract of T. aestivum (200 and 400 mg/kg/day, po, for 30 days) and risedronate (20 mg/kg, sc, five times a week for 30 days) following methyl prednisolone sodium succinate (10 mg/kg, sc, thrice a week for 4 weeks) induced osteoporosis in Wistar rats showed an increase in the serum levels of bone mineral content markers, decrease in the serum and urinary levels of bone resorption markers. An incline in strength of femur and tibia was seen particularly with 400 mg/kg of T. aestivum. Maintenance of calcium homeostasis, formation of collagen and scavenging of free radicals can plausibly be the mode of action of aqueous extract of T. aestivum thereby combating osteoporosis induced by glucocorticoids.

Etidronate from Medicine to Endodontics: effects of different irrigation regimes on root dentin roughness

An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. OBJECTIVES: To evaluate the effects of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated with different irrigation regimens on root dentin roughness. MATERIAL AND METHODS: Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control); G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra) was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05) was used to compare the values before and after treatments, and the Friedman test (α<0.05) to detect any differences among root thirds. RESULTS: (i) NaOCl did not affect the surface roughness; (ii) there was a significant increase in roughness after the use of chelating agents (P<0.01); and (iii) only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043). CONCLUSION: Only the irrigation regimens that used chelating agents altered the roughness of root dentin. .

Establishment of zebrafish osteopenia model induced by dexamethasone / 药学学报

Zebrafish was selected as model animal, and glucocorticoid dexamethasone was used as a model compound to establish a rapid and high efficient osteopenia model. Zebrafish larvae at 4 days post fertilization (dpf) were exposed to a serial concentrations of dexamethasone solutions, and 0.5% DMSO was selected as the vehicle control group. All groups were incubated in 24-well plates (28.5 degrees C) until 9 dpf. In addition, effects of 10 micromol x L(-1) dexamethasone on preventing against osteopenia induced by etidronate disodium were also investigated. Zebrafish bones at 9 dpf were stained with alizarin red. Quantitative analysis of the stained area was performed by microscopic inspection and digital imaging methods to reflect the amount of bone mineralization. Results showed that dexamethasone group at 2.5, 10 and 25 micromol x L(-1) can decrease the staining area and the staining optical density values of zebrafish head bones when compared with the vehicle control group (0.5% DMSO), which suggested that dexamethasone can significantly reduce the zebrafish mineralized bone and the bone mineral density. Results also showed that 15 and 30 microg x mL(-1) etidronate disodium can increase the mineralized matrix of zebrafish head bone and prevent against osteopenia induced by dexamethasone. In conclusion, the study indicated that zebrafish can be an idea osteopenia model induced by dexamethasone.

Comparison of the efficacy of three once-weekly bisphosphonates on bone mineral density gains in Korean women

OBJECTIVE: To assess the efficacies of once-weekly bisphosphonates on bone mineral density (BMD) gains in Korean women aged 50 years or more. METHODS: We selected 166 patients who received: alendronate 70 mg (n=48), alendronate 70 mg + cholecalciferol 2,800 IU (n=31) or risedronate 35 mg (n=87) for one year. The baseline BMD and the % changes of BMD at one-year were compared among the three medication groups. RESULTS: The menopausal status and number of women with osteoporosis was not different among the three groups, but mean age of women was significantly lower in alendronate group. Baseline BMD at L1-4 and femur neck (FN) was similar, but baseline BMD at femur total (FT) was significantly lower in alendronate group. After one-year use, the median % changes of BMD at three sites were similar among the three groups; however, the median values were highest in alendronate + cholecalciferol group (L1-4: 4.48%, 6.74%, and 4.50%; FT: 2.09%, 3.70%, and 2.31%; FN: 3.05%, 3.79%, and 2.03%). CONCLUSION: Among three once-weekly bisphosphonates, BMD gains were highest after one-year use of alendronate+cholecalciferol, although statistically not significant.

Bisphosphonates-related osteonecrosis of the jaw in Korea: a preliminary report

OBJECTIVES: Bisphosphonates (BP) are widely used in medicine for inhibiting bone resorption; however bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a major side effect of BP. To date, there have been no specific reports on the incidence of BRONJ among Koreans. This study investigated the preliminary results from a nationwide survey of BRONJ in the Departments of Oral and Maxillofacial Surgery (OMFS) at individual training hospitals. MATERIALS AND METHODS: A total of 15 OMFS departments (10 from dental schools, 4 from medical schools, and 1 from a dental hospital) participated in a multi-centric survey. This study assessed every BRONJ case diagnosed between January 2010 and December 2010. The patient age and BP type were evaluated. RESULTS: A total of 254 BRONJ cases were collected. The majority of BRONJ cases were associated with oral BP therapy, while 21.8% of the cases were associated with intravenous administration. Alendronate was the drug most frequently related to BRONJ (59.2% of cases), followed by risedronate (14.3%) and zolendronate (17.0%). The average age of BRONJ patients was 70.0+/-10.1 years, with a range of 38-88 years of age. With the number of BP patients in Korea reported to be around 600,000 in 2008, the estimated incidence of BRONJ is at least 0.04% or 1 per 2,300 BP patients. CONCLUSION: The results suggest that the estimated incidence of BRONJ in Korea is higher than the incidence of other countries. Future prospective studies should be carried out to investigate the exact epidemiological characteristics of BRONJ in Korea.

Bisphosphonates-related osteonecrosis of the jaw in Korea: a preliminary report

OBJECTIVES: Bisphosphonates (BP) are widely used in medicine for inhibiting bone resorption; however bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a major side effect of BP. To date, there have been no specific reports on the incidence of BRONJ among Koreans. This study investigated the preliminary results from a nationwide survey of BRONJ in the Departments of Oral and Maxillofacial Surgery (OMFS) at individual training hospitals. MATERIALS AND METHODS: A total of 15 OMFS departments (10 from dental schools, 4 from medical schools, and 1 from a dental hospital) participated in a multi-centric survey. This study assessed every BRONJ case diagnosed between January 2010 and December 2010. The patient age and BP type were evaluated. RESULTS: A total of 254 BRONJ cases were collected. The majority of BRONJ cases were associated with oral BP therapy, while 21.8% of the cases were associated with intravenous administration. Alendronate was the drug most frequently related to BRONJ (59.2% of cases), followed by risedronate (14.3%) and zolendronate (17.0%). The average age of BRONJ patients was 70.0+/-10.1 years, with a range of 38-88 years of age. With the number of BP patients in Korea reported to be around 600,000 in 2008, the estimated incidence of BRONJ is at least 0.04% or 1 per 2,300 BP patients. CONCLUSION: The results suggest that the estimated incidence of BRONJ in Korea is higher than the incidence of other countries. Future prospective studies should be carried out to investigate the exact epidemiological characteristics of BRONJ in Korea.

Changes in Serum Osteocalcin are Not Associated with Changes in Glucose or Insulin for Osteoporotic Patients Treated with Bisphosphonate

BACKGROUND: Bisphosphonate is used in osteoporosis treatment to repress osteoclast activity, which then decreases levels of osteocalcin (OC). OC, a protein secreted by osteoblasts and released from the bone matrix during osteoclastic bone resorption, has been found to control blood glucose levels by increasing insulin production and sensitivity. The question addressed in this study is whether decreasing OC through bisphosphonate treatment will provoke a change in glucose homeostasis. METHODS: Eighty-four patients with osteoporosis were treated with once-weekly risedronate 35 mg and cholecalciferol 5,600 IU. We measured fasting plasma glucose (FPG), insulin, and undercarboxylated (Glu) and carboxylated (Gla) OC levels at baseline and after 16 weeks. To estimate insulin resistance (IR) and beta-cell function (B)%, homeostasis model assessment (HOMA)-IR and HOMA-B% were also calculated, respectively. RESULTS: The mean FPG level in total subjects increased significantly from 5.3 to 5.5 mmol/L, but no changes in blood glucose were noted in the 24 subjects with impaired fasting glucose. Glu and Gla OC levels declined significantly after treatment. No correlations were observed between changes in OC and changes in glucose, however. CONCLUSIONS: Bisphosphonate treatment for osteoporosis reduced OC, but this change was not associated with changes in glucose metabolism.

A Case of Vitamin D Deficiency with Secondary Hyperparathyroidism and Brown Tumor / 대한골다공증학회지

The importance of vitamin D for skeletal health is well known. Vitamin D deficiency causes secondary hyperparathyroidism, high bone turnover, bone loss, and osteoporotic fractures. We report a case of a 60-year-old women presenting with brown tumor in the proximal femur secondary to vitamin D deficiency and secondary hyperparathyroidism. She took calcium supplements and vitamin D3 for 1 year and half dose of risedronate was prescribed for 5 months. After 1 year, pain in the pelvis was much improved and Bone mineral density of the lumbar spine and femoral neck increased by 37% and 29%, respectively.

1-34 PTH Could Reverse Impaired Bone Mineralization Induced By the Overdose of Bisphosphonate

Bisphosphonates are the mainstay of osteoporosis treatment. Despite the fact that bisphosphonates have a relatively good safety record and are tolerated well by the majority of patients, serious adverse events have been associated with their use. A 41-year-old man had been diagnosed with osteoporosis and had taken etidronate 200 mg/day daily for 2 years due to the judgmental error. He was referred for the management of refractory bone pain and generalized muscle ache. Serum calcium, phosphate, 25-hydroxy-vitamin D (25(OH)D), and immunoreactive parathyroid hormone (iPTH) were within normal range. Plain X-ray showed multiple fractures. Whole body bone scan confirmed multiple sites of increased bone uptakes. Tetracycline-labeled bone biopsy showed typical findings of osteomalacia. He was diagnosed with iatrogenic, etidronate-induced osteomalacia. The patient received daily parathyroid hormone (PTH) injection for 18 months. PTH effectively reverses impaired bone mineralization caused by etidronate misuse. Currently, he is doing well without bone pain. Bone mineral density significantly increased, and the increased bone uptake was almost normalized after 18 months. This case seems to suggest that human PTH (1-34) therapy, possibly in association with calcium and vitamin D, is associated with important clinical improvements in patients with impaired bone mineralization due to the side effect of bisphosphonate.

Risedronate-related Localized Amnesia in an Elderly Patient with Osteoporosis

Osteoporosis is the most common metabolic bone disease that results in an increased risk of fragility fractures. Bisphosphonates are commonly used in the treatment of osteoporosis. Concerns about their association with several possible adverse effects have been raised. Here, we experienced a rare case regarding a 63-year-old female patient who had localized amnesia related to once-monthly oral risedronate. A clear cause-and-effect relationship between the treatment of risedronate and this event has not been established and the mechanism behind the adverse effect is unknown. As clinical uses of bisphosphonates continue to expand, clinicians should be aware of the rare but potential adverse effects associated with bisphosphonates including neuropsychiatric problems.

Clinical study of correlation between C-terminal cross-linking telopeptide of type I collagen and risk assessment, severity of disease, healing after early surgical intervention in patients with bisphophonate-related osteonecrosis of the jaws

INTRODUCTION: The utility of the C-terminal cross-linking telopeptide test (CTX) as a method for staging Bisphosphonate-related osteonecrosis of the jaws (BRONJ) and its healing process was examined. MATERIALS AND METHODS: A total 19 patients who were diagnosed with BRONJ underwent a fasted morning CTX test, were enrolled in this study. The serum CTX values ranged from 50 to 630 pg/mL (mean 60). The risk assessment was rated according to the CTX values of the individual patient (minimal risk, > or =150 pg/mL, moderate, 100 to 150 pg/mL, high, < or =100 pg/mL). The BRONJ scores were then calculated according to the number of BRONJ lesions and their stage. The operation was done as soon as possible, regardless of BORNJ stage. RESULTS: The mean duration of bisphosphonate therapy was 4.1 years. Of the 19 patients, 15, 2 ans 2 received alendronate, risedronate and zoledronate, respecively. Of the 19 patients who underwent a sequestrectomy, saucerization and smoothing, 15 healed after the initial surgery, 1 patient healed after one more surgical procedure, 3 patients did not heal completely but showed improvement in symptoms. Therefore, 17 out of the 19 patients healed completely with complete mucosal coverage and the elimination of pain. The risk assessment using the CTX value and disease severity were not correlated (r=-0.264, P=0.275). In addition, the risk assessment using CTX value and healing after surgery were not correlated (r=-0.147, P=0.547). CONCLUSION: The serum CTX should be considered carefully by clinicians as part of overall management. Early surgical intervention is of benefit in the treatment of stage II BRONJ.

Nivel de satisfacción con pamidronato disódico en el tratamiento de osteogénesis imperfecta: trabajo realizado en el Hospital Ortopédico Infantil Caracas Venezuela / Level of satisfaction with pamidronate disodium in the treatment of osteogenesis imperfecta: work Hospital Ortopédico Infantil Caracas Venezuela

Se realizó un estudio descriptivo, prospectivo, de tipo transversal para determinar el nivel de satisfacción en 101 pacientes con Osteogénesis Imperfecta en el tratamiento con Pamidronato. Se contactaron por encuesta vía telefónica a 52 pacientes quienes contaban con al menos dos ciclos de tratamiento.De 505 fracturas reportadas, el 71% se produjeron previas al tratamiento, evidenciándose disminución del 42% de fracturas. 69 % de los pacientes no refieren dolor posterior al tratamiento en comparación con el 27% que no refieren dolor previo al tratamiento. El porcentaje de pacientes capaces de caminar de manera independiente aumentó 21%, disminuyendo 31% de paciente confinados al lecho o silla de ruedas. El porcentaje de mejoría, conformidad y recomendación del tratamiento es favorable en casi 100% de los entrevistados. El tratamiento con Pamidronato mejora la calidad de vida de los pacientes con Osteogénesis Imperfecta.

We present a descriptive study to evaluate the level of satisfaction in 101 patients with Osteogenesis Imperfecta in treatment with Pamidronato. We contact 52 patient for an enquire by telephone, who have 2 or more ciclos of treatment. From 505 fractures report, the 71% was until treatment, we found disminution of 42% of fractures. 69% of patients don’t refer pain after treatment in comparison with the 27% that do not refer pain until treatment. The porcent of patients capables of walk independent increase 21%, decrease 31% of patients that can not walk. The porcent of improvement, conformity and recomendation of treatment is good in also 100% of interview. The treatment with Pamidronato improve the life quality in the patients with Osteogenesis Imperfecta.

Effects of Risedronate on Osteoarthritis of the Knee

The purpose of the present study was to discuss the effects of risedronate on osteoarthritis (OA) of the knee by reviewing the existing literature. The literature was searched with PubMed, with respect to prospective, double-blind, randomized placebo-controlled trials (RCTs), using the following search terms: risedronate, knee, and osteoarthritis. Two RCTs met the criteria. A RCT (n = 231) showed that risedronate treatment (15 mg/day) for 1 year improved symptoms. A larger RCT (n = 1,896) showed that risedronate treatment (5 mg/day, 15 mg/day, 35 mg/week, and 50 mg/week) for 2 years did not improve signs or symptoms, nor did it alter radiological progression. However, a subanalysis study (n = 477) revealed that patients with marked cartilage loss preserved the structural integrity of subchondral bone by risedronate treatment (15 mg/day and 50 mg/week). Another subanalysis study (n = 1,885) revealed that C-terminal crosslinking telopeptide of type II collagen (CTX-II) decreased with risedronate treatment in a dose-dependent manner, and levels reached after 6 months were associated with radiological progression at 2 years. The results of these RCTs show that risedronate reduces the marker of cartilage degradation (CTX-II), which could contribute to attenuation of radiological progression of OA by preserving the structural integrity of subchondral bone. The review of the literature suggests that higher doses of risedronate (15 mg/day) strongly reduces the marker of cartilage degradation (CTX-II), which could contribute to attenuation of radiological progression of OA by preserving the structural integrity of subchondral bone.