A comparison of the physicochemical properties of AH Plus Jet with samples taken from the beginning, middle and final portions of the automix syringe system

Aim To evaluate physicochemical properties and semi-quantitative elemental analysis of AH Plus Jet with samples from the beginning, middle and final portions of the automix syringe system. Methodology Three experimental groups based on the source of the material used (beginning, middle and final portion) were established for each of the evaluated properties. Setting time, flow and radiopacity were evaluate following ANSI/ADA n. 57 specification. Set specimens was used in the semi-quantitative elemental analysis in an energy-dispersive X ray spectroscopy and scanning-electron microscopy (EDS/SEM). Statistical analysis was performed using one-way ANOVA followed by Tukey test (P<0.05). Results Flow, setting time, solubility and EDS/SEM tests showed no significant differences among the three portions of the automix syringe (P>0.05). Radiopacity test showed significant differences in the beginning of the syringe comparing to the middle and final portions (P<0.05). EDS/SEM analysis identified the presence of C, O, Al, Ca, Zr and W. The element Al, however, was found only in the final portion of the syringe. Conclusions The results of AH Plus Jet suggested an adequate ratio of the components, without segregation between organic and inorganic components, since the results of setting time, flow, solubility and EDS/SEM analysis presented similar values regardless of the portion of the syringe from where the sealer was taken.

Influência da ativação ultrassônica e veículo no pH dentinário em dentes com reabsorção radicular externa simulada reparados com MTA / Influence of ultrasonic activation and mixing vehicle on dentinal pH in simulated external root resorptions repaired with MTA

Avaliar o efeito da ativação ultrassônica e do veículo do MTA no pH dentinário em dentes com reabsorção radicular externa simulada. Métodos: Uma cavidade foi preparada na superfície radicular de 46 dentes bovinos, as quais foram seladas com MTA preparado com 100% de água destilada (DW) ou com 80% DW e 20% de propilenoglicol (PG). Os dentes foram divididos em quatro grupos (n = 10), de acordo com o veículo e o protocolo de ativação ultrassônica utilizado durante a inserção do material (ativação ou sem ativação). O grupo controle (n = 6) foi deixado sem selamento. O pH foi mensurado após 15, 30 e 60 dias de imersão. Resultados: A ativação com ultrassom não alterou significativamente o pH (p>0,05). Os cimentos manipulados utilizando DW + PG apresentaram maior pH aos 15 dias, em relação ao MTA manipulado com DW (p<0,05). Conclusão: A associação de 80% de água destilada com 20% de propilenoglicol aumentou o pH dentinário, o que é positivo para o reparo de reabsorções radiculares (AU).

The aim of this study was to evaluate the effect of ultrasonic activation and MTA vehicle on dentinal pH in simulated external root resorptions. So, a cavity was prepared in the root of forty-six bovine teeth. They were filled with MTA mixed with 100% distilled water (DW) or MTA mixed with 80% DW and 20% propylene glycol (PG). Teeth were divided into four groups (n = 10), according to the vehicle (DW or PG) and ultrasonic protocol used for material insertion (activated or not). Control group (n = 6) was unfilled. The pH was assessed after 15, 30 and 60 days of immersion. As results of all that, activation with ultrasound did not significantly alter the pH (p > 0.05). The cements were mixed with either DW or DW + PG, with the later association presenting higher pH at 15 days of assessment than the former (p < 0.05). Thereby, it can be concluded that mixing MTA with 80% DW and 20% PG increased the dentinal pH, which is positive for root resorption repair (AU).

Antimicrobial activity and physicochemical properties of antibiotic pastes used in regenerative endodontics

Abstract: The purpose of this study was to evaluate the pH, solubility and antimicrobial action of Calcium Hydroxide Paste (CH), Double Antibiotic Paste (metronidazole+ciprofloxacin-DAP), calcium hydroxide added to DAP (CH/DAP) and Triple Antibiotic Paste (metronidazole + ciprofloxacin+minocycline-TAP). pH (n=10) were measured by pHmeter. Root canals of acrylic teeth (n=10) were filled with the above-mentioned intracanal-dressings, immersed in ultrapure water, and solubility was measured by the difference between the initial and final volume (7,15 and 30 days) by using micro-computed tomography. Enterococcus faecalis biofilm was induced on bovine dentin disc surfaces (n=20), and treated with the pastes for 7 days. Percentage bacterial viability was verified by confocal microscope, with LIVE/DEAD dye. CH and CH/DAP presented the highest pH values. Regarding solubility, after 7 days, antibiotic groups presented significant volume loss. CH and CH/DAP showed no statistical difference compared with the Control in antimicrobial action against E. faecalis biofilm. However, TAP and DAP presented a significant percentage reduction in bacterial population. Due to high solubility of the pastes, renewing antibiotic dressings every 7 days, or using the medications for this period in regeneration protocols is recommended. DAP is indicated for killing E. faecalis in biofilm because it has antimicrobial action similar to TAP. Adding Calcium Hydroxide to DAP significantly decreased its antimicrobial action. In spite of its the low solubility and high pH values, the CH paste showed a low level of antimicrobial action against E. faecalis in biofilm.

Resumo A proposição deste estudo foi avaliar o pH, solubilidade e ação antimicrobiana da pasta de Hidróxido de Cálcio (HC), Pasta Diantibiótica (metronidazol+ciprofloxacina-DAP), Hidróxido de Cálcio adicionado a DAP (HC/DAP) e pasta Triantibiótica (metronidazol + ciprofloxacina + miociclina - TAP). a medição do pH e liberação de íons cálcio (n=10) foram avaliadas através de peagômetro e espectofotômetro de absorção atômica. Canais de dentes de acrílico (n=10) foram preenchidos com as medicações de canal mencionadas, imersos em água ultrapura e a solubilidade foi aferida pela diferença entre o volume inicial e final (7,15 e 30 dias) usando micro tomografia computadorizada. O biofilme de Enterococcus faecalis foi induzido em blocos de dentina bovina (n=20) e tratados com as pastas em questão por 7 dias. A porcentagem de bactérias vivas foi verificada usando o microscópio confocal com corante LIVE/DEAD. HC e HC/DAP apresentaram os maiores valores de pH e liberação de íons cálcio. A respeito da solubilidade, depois de 7 dias, os grupos com pastas antibióticas apresentaram perda de volume significante. HC e HC/DAP não tiveram diferenças estatísticas com o grupo controle na ação antimicrobiana contra biofilme. No entanto, a TAP e a DAP mostraram porcentagem significante de redução bacteriana. Conclusões: Devido à alta solubilidade das pastas, renovar as medicações antibióticas a cada 7 dias ou usa-las por esse período em protocolos regenerativos é recomendado. DAP é indicada para matar E. faecalis na forma de biofilme porque tem ação antimicrobiana similar a TAP. A adição do CH à DAP reduz significantemente sua ação antimicrobiana. Apesar da baixa solubilidade e altos valores de pH, a pasta de CH apresenta baixa ação antimicrobiana contra E. faecalis em biofilme.

Influência de substâncias irrigadoras em gel sobre o biofilme microbiano / Influence of gel irrigant agents in oral biofilm

Objetivo: o objetivo do presente estudo foi avaliar a ação antimicrobiana do hipoclorito de sódio a 1%, da clorexidina a 2% e do EDTA a 24% ­ todos na forma de gel ­, sobre o biofilme oral. Métodos: blocos de dentina bovina estéreis foram inseridos em um dispositivo intrabucal, o qual foi utilizado por um voluntário durante 3 dias. Após a formação do biofilme, os blocos foram imersos em 100 µl das diferentes substâncias avaliadas, durante 5 minutos. Após o tratamento, as amostras foram coradas com 50 µl de uma solução com iodeto de propídio e SYTO 9, e avaliadas em um microscópio confocal imediatamente após a remoção do agente antimicrobiano, gerando um total de 50 imagens por grupo. Os dados foram analisados por meio dos testes de Kruskal-Wallis e Dunn (α = 0,05). Resultados: diferenças estatísticas entre os grupos experimentais e controle foram observadas. O hipoclorito de sódio a 1% foi mais eficaz do que as outras substâncias avaliadas (p < 0,05). Ainda, a clorexidina a 2% reduziu a porcentagem de células vivas de forma mais significativa, comparada ao EDTA (p < 0,05). Conclusões: os agentes irrigantes utilizados nesse estudo não apresentaram capacidade de dissolução do biofilme formado in situ. No entanto, o hipoclorito de sódio apresentou melhores resultados, quanto comparado à clorexidina e ao EDTA.

Influência do cimento na radiopacidade de obturações com cone único / Sealer influence on radiopacity of single cone root canal fillings

Objetivo: o objetivo deste estudo foi avaliar a influência dos cimentos AH Plus e Endofill na radiopacidade de obturações em canais simulados, usando-se a técnica do cone único. Métodos: vinte blocos de resina com canais curvos simulados foram preparados até o instrumento rotatório ProTaper Universal F3. Após a irrigação final, os canais foram secos com cones de papel, e um cone de guta-percha F3 foi inserido no canal; em seguida, uma radiografia digital foi realizada para cada espécime. Os espécimes foram distribuídos aleatoriamente em dois grupos experimentais (n = 10), de acordo com cimento empregado. AH Plus e Endofill foram os cimentos associados à guta-percha para obturação dos canais. Após a presa final dos cimentos, novas imagens digitais foram realizadas, da mesma forma que as radiografias pré-operatórias. As imagens das radiografias antes e após a associação da guta-percha com o cimento foram sobrepostas e analisadas, para se registrar o número de pixels das imagens. A análise estatística foi realizada utilizando-se os testes t de Student e Wilcoxon, com nível de significância de 5%. Resultados: ambos os grupos apresentaram radiopacidade semelhante para a guta-percha (p > 0,05). No entanto, a adição do cimento aumentou significativamente (p < 0,05) a radiopacidade das imagens radiográficas. A radiopacidade foi aumentada em 68,10% com o cimento AH Plus e em 46,02% com o cimento Endofill, com diferença estatisticamente significativa entre os cimentos. Conclusões: os cimentos aumentaram significativamente a radiopacidade da obturação com a técnica do cone único. O cimento AH Plus foi mais radiopaco do que o cimento Endofill.

Influence of NiTi alloy on the root canal shaping capabilities of the ProTaper Universal and ProTaper Gold rotary instrument systems

Abstract Objective This study aimed to evaluate the influence of the NiTi wire in Conventional NiTi (ProTaper Universal PTU) and Controlled Memory NiTi (ProTaper Gold PTG) instrument systems on the quality of root canal preparation. Material and Methods Twelve mandibular molars with separate mesial canals were scanned using a high-definition microcomputed tomography system. The PTU and PTG instruments were used to shape twelve mesial canals each. The canals were scanned after preparation with F2 and F3 instruments of the PTU and PTG systems. The analyzed parameters included the remaining dentin thickness at the apical and cervical levels, root canal volume and untouched canal walls. Data was analyzed for statistical significance by the Friedman and Dunn’s tests. For the comparison of data between groups, the Mann-Whitney test was used. Results In the pre-operative analysis, there were no statistically significant differences between the groups in terms of the area and volume of root canals (P>.05). There was also no statistically significant difference between the systems with respect to root canal volume after use of the F2 and F3 instruments. There was no statistical difference in the dentin thickness at the first apical level between, before and after instrumentation for both systems. At the 3 cervical levels, the PTG maintained centralization of the preparation on the transition between the F2 and F3 instruments, which did not occur with the PTU. Conclusion The Conventional NiTi (PTU) and Controlled Memory NiTi (PTG) instruments displayed comparable capabilities for shaping the straight mesial root canals of mandibular molars, although the PTG was better than the PTU at maintaining the centralization of the shape in the cervical portion.

Influência do contato com sangue e soro fisiológico na solubilidade, pH e constituição química do MTA / Influence of contact with blood and saline on solubility, pH and chemical composition of MTA

Objetivo: o objetivo deste estudo foi avaliar a solubilidade, pH e composição química do MTA branco em contato com sangue e soro fisiológico. Métodos: trinta réplicas de incisivos centrais superiores em acrílico, com retrocavidades com 3 mm de profundidade, foram preenchidas com MTA branco. Os espécimes foram individualmente inseridos em microtubos e divididos em três grupos (n = 10): no Grupo 1, as amostras não foram expostas a líquidos (grupo controle); no grupo 2, os microtubos receberam 1 mL de soro fisiológico; e no Grupo 3, receberam 1 mL de sangue humano fresco. As amostras foram armazenadas a 37°C durante 24 horas. A solubilidade foi avaliada volumetricamente, de modo que os espécimes foram escaneados por Micro-CT e individualmente imersos em 10 mL de água ultrapura; após 168 horas, novos escaneamentos foram realizados. O nível de pH foi mensurado após 168 horas. Secções das amostras com 2 mm de espessura foram analisadas por meio de espectroscopia de energia dispersiva, para avaliar a composição iônica. Os dados foram analisados estatisticamente pelos testes ANOVA e Tukey. Resultados: a solubilidade foi similar (p > 0,05) para todos os grupos. Após 168 horas, o pH foi significativamente maior para o Grupo 2, em comparação ao Grupo 3 (p < 0,05). Quanto à composição iônica, foi encontrada maior concentração de cálcio e o contato com sangue não interferiu na liberação de íons de cálcio. Conclusão: o contato do sangue e soro fisiológico com o MTA não influenciou na solubilidade, ambos favoreceram um pH alcalino, com o aumento da liberação de íons cálcio, com pequenas variações na composição iônica.

Medication-related osteonecrosis of the jaw. Introduction of a new modified experimental model

ABSTRACT PURPOSE : To evaluate a modified experimental model for medication-related osteonecrosis of the jaw (MRONJ) through the upper right central incisor extraction followed by intravenous bisphosphonate administration. METHODS: Forty five rats underwent the upper right central incisor tooth extraction were divided in 2 groups: Group I - experimental group, 30 rats received an intravenous administration protocol of zoledronic acid 35μg/kg into the tail vein every two weeks, totalizing four administrations, during eight weeks of administration, previously the extraction, and Group II - control group, 15 rats didn't received any medication before extraction. The groups were subdivided in postoperative periods: 14/28/42 days. Clinical analysis and microtomography were performed to verify the presence of osteonecrosis. In addition, descritive histological analysis of hematoxylin-eosin stained sections was performed to evaluate the presence of osteonecrosis or necrotic foci. RESULTS: Twelve (40%) rats, from experimental group, showed clinical signs of MRONJ (p=0.005), however, all samples showed imaginologic findings like osteolysis and loss of integrity of the cellular walls (p≤0.001). Microscopic evaluation revealed osteonecrosis areas with microbial colonies and inflammatory infiltrate (p≤0.001). In the control group, all animals presented the chronology of a normal wound healing. CONCLUSIONS: The presence of medication-related osteonecrosis of the jaw after maxillary central incisor extraction in rats. This new experimental model may be considered an option for the study of MRONJ.

Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study

ABSTRACT Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Efficacy of ultrasonic activation of NaOCl and orange oil in removing filling material from mesial canals of mandibular molars with and without isthmus

Objectives The aim of this study was to evaluate the volume of remaining filling material after passive ultrasonic irrigation (PUI) of sodium hypochlorite (NaOCl) and orange oil in mesial canals of mandibular molars, with and without isthmus. Material and Methods Thirty mesial roots of mandibular molars were divided according to the presence or absence of isthmus. Canals were prepared and filled (Micro-CT #1). Filling was removed using rotary instruments, and specimens were sub-divided into three groups according to the irrigation procedures: Conventional – conventional irrigation with NaOCl, PUI/NaOCl – PUI of NaOCl (three activations, 20 seconds each), and PUI/orange oil – PUI of orange oil (Micro-CT#2). Specimens were enlarged using the X2 and X3 ProTaper Next instruments and submitted to the same irrigation protocols (Micro-CT #3). Results No differences were found between the experimental groups in each stage of assessment (P>0.05). The volume of residual filling material was similar to that in Micro-CT #2 and Micro-CT #3, but lower than that observed in Micro-CT #1 (P<0.05). When groups were pooled according to the presence or absence of an isthmus, volume of residual filling material was higher in specimens presenting isthmus (P<0.05). Conclusions PUI of NaOCl or orange oil did not improve filling removal. Isthmus consists in an anatomical obstacle that impairs the removal of filling material.

Ex vivo Analysis of Three Electronic Apex Locators Accuracy with Different Settings.

Aims: The correct determination of a root canal length is a fundamental step for an adequate chemical-mechanical preparation and consequently, for a successful endodontic treatment. Electronic apex locators (EAL) were developed to provide fast and reliable working lengths. The aim of the present study was to analyze the accuracy of the Root ZX II, RomiApex A-15, and SmarPex EAL’s to determine the location of apical constriction, with and without the instructions recommended by the manufacturers. Methodology: Fifteen mandibular premolars were randomly selected and root canals were accessed. The real canal length was determined by introducing a #15 K-file until the tip was visualized in the apical foramen, using 40x magnification of an operative microscope. In the sequence, the teeth were inserted in plastic flasks containing floral foam soaked in 0.9% saline solution. The root canals were filled with 1% sodium hypochlorite and the electronic measures were obtained with the selected devices until the “0.0” or the last green bar mark, as showed in devices display, and as per the manufacturers settings recommendation. The data were submitted to statistical analysis with the Friedman and Wilcoxon tests with a 0.05% significance level (p < 0.05). Results: All devices were similar (p > 0.05) and showed precise and acceptable measurements at both times. Without manufacturers setting recommendation, the Root ZX II was the EAL that presented the greater percentage of coincidences with the real teeth length measures (73.33%), followed by the RomiApex A-15 (66.66%) and the SmarPex (40%). After performing the recommended settings the Root ZX II and the SmarPex presented 86.66% of coincidence with the real length, however, only the SmarPex device enhanced the mean precision with the real length (p < 0.05). Conclusion: Considering a clinically acceptable average error of ±0.5 mm, all devices were effective in determining the measurement until the apical constriction. Although, there were no statistical significant difference with and without manufacturers instruction, for Root ZX II, the performance was better when manufacturer instructions were followed.

Micro-CT Evaluation of Root Filling Removal after Three Stages of Retreatment Procedure

The aim of this study was to quantify the residual filling material after filling removal, re-preparation with rotary or reciprocating files and passive ultrasonic irrigation (PUI). Twenty maxillary molars were prepared using ProTaper instruments up to F1. The teeth were filled with AH Plus and ProTaper gutta-percha points using the single-cone technique. Thereafter, the specimens were scanned using a micro-computed tomography system (Micro-CT #1). Then, the root canal filling was removed using ProTaper Retreatment files, and a new scan was performed (Micro-CT #2). The specimens were divided into two groups according to the instrument used for re-preparation: ProTaper rotary or WaveOne reciprocating files (Micro-CT #3). Finally, PUI was performed, and a new micro-CT scan was performed (Micro-CT #4). Intragroup and intergroup analyses were performed using Friedman and Dunn's post hoc test and the Kruskal-Wallis and Dunn post hoc tests, respectively. Palatal canal presented the highest volume of residual filling material in all stages of endodontic retreatment (p<0.05). The main reduction of filling volume was achieved after using ProTaper Retreament (p<0.05). The amount of remaining filling material after using ProTaper Retreatment was similar to that achieved with rotary and reciprocating files and after PUI (p>0.05). Rotary and reciprocating files achieved similar removal of the root canal filling (p>0.05). The greatest reduction in filling material was achieved after using ProTaper Retreatment files. Rotary and reciprocating instruments and PUI did not improve the removal of root canal filling materials.

Resumo O objetivo dente estudo foi quantificar o material obturador residual após remoção da obturação, repreparo do canal com instrumentos de rotação contínua e reciprocantes e após irrigação ultrassônica passiva (IUP). Vinte molares superiores foram preparados usando instrumentos ProTaper sequencialmente até F1. Os dentes foram obturados com AH Plus e cones de guta percha ProTaper utilizando a técnica de cone único. Em seguida, os espécimes foram submetidos à microtomografia computadorizada (Micro-CT #1). Então, o material obturador foi removido utilizando instrumentos ProTaper Retratamento e novo escaneamento foi realizado (Micro-CT #2). Os espécimes foram divididos em dois grupos de acordo com o instrumento usado para o repreparo: de rotação contínua (ProTaper) ou reciprocante (WaveOne) (Micro-CT #3). Finalmente, IUP foi realizada e nova micro-CT foi conduzida (Micro-CT #4). As análises intra-grupo e inter-grupos foram realizadas utilizando os testes de Friedman e de Dunn e o teste de Kruskal-Wallis e Dunn, respectivamente. O canal palatino apresentou o maior volume de material obturador remanescente em todos os estágios do tratamento endodôntico (p<0,05). A maior redução do volume da obturação foi obtida após usar os instrumentos ProTaper Retratamento (p<0,05). A quantidade de material obturador remanescente após utilizar instrumentos ProTaper Retratamento foi similar àquela obtida após repreparo com instrumentos de rotação contínua e reciprocantes e após a IUP (p>0,05). Instrumentos de rotação contínua e reciprocantes proporcionaram similar remoção de material obturador (p>0,05). A maior redução do volume de material obturador foi obtida após utilizar os instrumentos ProTaper Retratamento. Instrumentos de rotação contínua e reciprocantes, assim como a IUP, não reduzíram o volume de material obturador remanescente.

Filling Effectiveness and Dentinal Penetration of Endodontic Sealers: A Stereo and Confocal Laser Scanning Microscopy Study

Abstract: The aim of this study was to evaluate the filling effectiveness and dentinal penetration of the sealers AH Plus, Pulp Canal Sealer EWT, Sealapex and MTA Fillapex applied according to the vertical condensation technique using thermoplastic gutta-percha. Forty single-rooted teeth were selected. After chemical-mechanical preparation and root-canal filling, sections of the root (2, 4 and 6 mm from the apex) were obtained and analyzed by stereo microscopy and confocal laser scanning microscopy. Data were tabulated and statistically analyzed. With regard to the assessment of void spaces in the filling material at 2 mm from the apex, the sealers showed similar results, but at 4 and 6 mm from the apex, MTA Fillapex had inferior performance compared to AH Plus (at 4 mm), Pulp Canal Sealer EWT (at 4 and 6 mm) and Sealapex (at 6 mm) (p<0.05). With regard to the penetration into dentinal tubules at 2 mm from the apex, the sealers also showed similar results, but at 4 and 6 mm Pulp Canal Sealer EWT had an inferior performance compared to MTA Fillapex and AH Plus, respectively (p<0.05). All four sealers were found to be similar regarding adaptation of the filling material to the root canal walls, except the MTA Fillapex, which showed failures at 4 and 6 mm from the root apex. With regard to the ability to penetrate into the dentinal tubules, the sealers were found to be equivalent, except for the Pulp Canal Sealer EWT as it had poorer results at 4 and 6 mm compared to MTA Fillapex and AH Plus, respectively.

Resumo: O objetivo deste estudo foi avaliar a efetividade da obturação e capacidade de penetração no interior dos túbulos dentinários dos cimentos: AH Plus, Pulp Canal Sealer EWT, Sealapex e MTA Fillapex, associado à técnica de obturação da condensação vertical da guta-percha termoplastificada. Selecionou-se 40 dentes unirradiculados. Após o preparo químico-mecânico e obturação, secções das raízes (a 2, 4 e 6 mm do ápice) foram obtidas e analisadas através de microscopia estéreo e confocal de varredura a laser. Os dados foram tabulados e analisados estatisticamente. Em relação à avaliação de espaços vazios na obturação a 2 mm, os cimentos apresentaram resultados similares, entretanto a 4 e 6 mm MTA Fillapex apresentou desempenho inferior em relação a AH Plus (a 4 mm), Pulp Canal Sealer EWT (a 4 e 6 mm) e Sealapex (a 6 mm) (p<0,05). Em relação à capacidade de penetração nos túbulos dentinários a 2 mm, os cimentos apresentaram resultados similares, contudo a 4 e 6 mm, o Pulp Canal Sealer EWT mostrou-se inferior ao MTA Fillapex e AH Plus, respectivamente (p<0,05). Os quatro cimentos foram similares em relação à adaptação da obturação nas paredes dos canais radiculares, exceto o MTA Fillapex, que evidenciou falhas a 4 e 6 mm. Na capacidade de penetração nos túbulos dentinários, os cimentos foram equivalentes, exceto o Pulp Canal Sealer EW que se mostrou inferior a 4 e 6 mm, quando comparado com MTA Fillapex e AH Plus, respectivamente.

Analysis of the reaction of subcutaneous tissues in rats and the antimicrobial activity of calcium hydroxide paste used in association with different substances

The aim of this study was to evaluate the subcutaneous tissue response in rats and the antimicrobial activity of intracanal calcium hydroxide dressings mixed with different substances against E. faecalis. Fifty four rats were divided into three experimental groups according to the vehicle in the calcium hydroxide treatment: 0.4% chlorohexidine in propylene glycol (PG),Casearia sylvestris Sw in PG and calcium hydroxide+PG (control group). The pastes were placed into polyethylene tubes and implanted into the subcutaneous tissue. After 7, 14 and 30 days, the samples were processed and histologically evaluated (hematoxylin and eosin). The tissue surface in contact with the material was analyzed, and the quantitative analysis determined the volume density occupied by the inflammatory infiltrate (giant cells, polymorphonuclear cells and mononuclear cells), fibroblasts, collagen fibers and blood vessels. For the antimicrobial analysis, 20 dentin blocks infected with E. faecalis were treated with calcium hydroxide pastes in different vehicles; 0.4% chlorhexidine in PG, PG, extract fromCasearia sylvestris Sw in PG and a positive control (infection and without medication) for 7 days. The efficiency of the pastes was evaluated by the live/dead technique and confocal microscopy. The results showed that 0.4% chlorhexidine induced a higher inflammatory response than the other groups. The Casearia sylvestris Sw extract showed satisfactory results in relation to the intensity of the inflammatory response. In the microbiological test, there were no statistical differences between the evaluated intracanal dressings and the percentage of bacterial viability was between 33 and 42%. The control group showed an 86% viability. Antimicrobial components such as chlorhexidine or Casearia sylvestris Sw did not improve the antimicrobial activity against E. faecalis in comparison to the calcium hydroxide+PG treatment. In addition, the incorporation of chlorhexidine in the calcium hydroxide paste promoted the highest inflammatory response.

Rat subcutaneous tissue response to calcium silicate containing different arsenic concentrations

Objective: To evaluate the response of rat subcutaneous tissue in implanted polyethylene tubes that were filled with GMTA Angelus and Portland cements containing different arsenic concentrations. Material and Methods: Atomic absorption spectrophotometry was utilized to obtain the values of the arsenic concentration in the materials. Thirty-six rats were divided into 3 groups of 12 animals for each experimental period. Each animal received two implants of polyethylene tubes filled with different test cements and the lateral of the tubes was used as a control group. After 15, 30 and 60 days of implantation, the animals were killed and the specimens were prepared for descriptive and morphometric analysis considering: inflammatory cells, collagen fibers, fibroblasts, blood vessels and other components. The results were analyzed utilizing the Kuskal-Wallis test and the Dunn's Multiple test for comparison (p<0.05). Results: The materials showed, according to atomic absorption spectrophotometry, the following doses of arsenic: GMTA Angelus: 5.01 mg/kg, WPC Irajazinho: 0.69 mg/kg, GPC Minetti: 18.46 mg/kg and GPC Votoran: 10.76 mg/kg. In a 60-day periods, all specimens displayed a neoformation of connective tissue with a structure of fibrocellular aspect (capsule). Control groups and MTA Angelus produced the lower amount of inflammatory reaction and GPC Minetti, the highest reaction. Conclusions: There was no direct relationship between the concentration of arsenic present in the composition of the materials and the intensity of the inflammatory reactions. Higher values, as 18.46 mg/kg of arsenic in the cement, produce characteristics of severe inflammation reaction at the 60-day period. The best results were found in MTA angelus. .

O efeito do uso de fitoterápicos e da própolis nas propriedades físico-químicas, antimicrobiana e biocompatibilidade do MTA / The effect of the use of phytotherapics and propolis in physicochemical properties, antimicrobial and biocompatibility of MTA

O objetivo deste estudo foi avaliar as propriedades físico-químicas, antimicrobianas e biocompatibilidade do MTA branco manipulado com extratos aquoso e/ou em propilenoglicol da Arctium lappa L., Casearia sylvestris Sw. e própolis. Dentre os testes físico-químicos foram avaliados o tempo de presa, escoamento, pH, liberação de íons cálcio e alteração volumétrica. Para verificar o efeito antimicrobiano foram aplicadas as metodologias do contato direto (Enterococcus faecalis e a Cândida albicans) e da descontaminação dentinária, empregando a microscopia confocal de varredura laser para verificar a viabilidade de Enterococcus faecalis. Para a avaliação da biocompatibilidade, 162 ratos Wistar foram utilizados, onde cada animal recebeu dois implantes subcutâneos e um alveolar. Após os períodos experimentais de 15, 30 e 60 dias foram realizadas análises microtomográfica, histológica descritiva e histomorfométrica. Adicionalmente amostras do tecido alveolar foram processadas para dosagem das citocinas TNF-α e IL-10 por meio do ensaio imunoenzimático (ELISA). Os dados obtidos foram analisados estatisticamente com os testes ANOVA e Tukey ou Kruskal-Wallis e Dunn. Os resultados revelaram que a variação do veículo associado ao MTA aumentou significativamente o tempo de presa, no entanto, não houve influência na alteração volumétrica (P>0,05) e na capacidade do cimento em manter o meio alcalino e liberar íons cálcio. Os cimentos manipulados com extratos em propilenoglicol apresentaram maior escoamento (P<0,05). Apenas o extrato da própolis agregou ao MTA efeito contra o Enterococcus faecalis após 24 e 48 horas (descontaminação dentinária e contato direto respectivamente) e contra a Cândida albicans após 10 horas (P<0,05). De acordo com as avaliações histológica e histomorfométrica dos implantes em tecidos subcutâneo e alveolar não foi constatada diferença significativa entre os grupos experimentais quando comparados com o grupo no qual o MTA foi manipulado...

The aim of this study was to evaluate the physicochemical, antimicrobial properties and biocompatibility of white MTA mixed with aqueous or propylene glycol extracts of Arctium lappa L., Casearia sylvestris Sw. and propolis. Among physicochemical tests were evaluated the setting time, flowability, pH, ion calcium release and volumetric change. To verify the antimicrobial effects were applied the methods of direct contact (Enterococcus faecalis and Candida albicans) and dentin decontamination by using the confocal laser scanning microscopy to verify the Enterococcus faecalis viability. To evaluate the biocompatibility were used 162 Wistar rats. Each animal received one alveolar and two subcutaneous implants. After the experimental periods of 15, 30 and 60 days were performed the microtomography, histological description and histomorphometric analyses. Additionally alveolar tissue samples were processed for the measurement of TNF-α e IL-10 cytokines by enzyme-linked immunosorbent assay (ELISA). The data were statistically analyzed by the ANOVA and Tukey or KruskalWallis and Dunns tests. The results revealed that the variation of the vehicle associated to MTA significantly increased its setting time, however did not influence the volumetric change (P>0,05) and the cement's ability to maintain the alkaline medium and ion calcium release. Cements mixed with propylene glycol extracts showed higher flowability (P<0,05). Only propolis extract added to MTA the effect against E. faecalis after 24 and 48 hours (dentin decontamination and direct contact respectively) and against Candida albicans after 10 hours (P<0,05). According to the histological and histomorphometric evaluation of the implants in subcutaneous and alveolar tissue was not observed significant differences between the experimental groups in comparison to the reference group (MTA was mixed with distilled water). The microtomography analysis and expression of TNF-α and IL-10 showed...

O efeito do uso de fitoterápicos e da própolis nas propriedades físico-químicas, antimicrobiana e biocompatibilidade do MTA / The effect of the use of phytotherapics and propolis in physicochemical properties, antimicrobial and biocompatibility of MTA

O objetivo deste estudo foi avaliar as propriedades físico-químicas, antimicrobianas e biocompatibilidade do MTA branco manipulado com extratos aquoso e/ou em propilenoglicol da Arctium lappa L., Casearia sylvestris Sw. e própolis. Dentre os testes físico-químicos foram avaliados o tempo de presa, escoamento, pH, liberação de íons cálcio e alteração volumétrica. Para verificar o efeito antimicrobiano foram aplicadas as metodologias do contato direto (Enterococcus faecalis e a Cândida albicans) e da descontaminação dentinária, empregando a microscopia confocal de varredura laser para verificar a viabilidade de Enterococcus faecalis. Para a avaliação da biocompatibilidade, 162 ratos Wistar foram utilizados, onde cada animal recebeu dois implantes subcutâneos e um alveolar. Após os períodos experimentais de 15, 30 e 60 dias foram realizadas análises microtomográfica, histológica descritiva e histomorfométrica. Adicionalmente amostras do tecido alveolar foram processadas para dosagem das citocinas TNF-α e IL-10 por meio do ensaio imunoenzimático (ELISA). Os dados obtidos foram analisados estatisticamente com os testes ANOVA e Tukey ou Kruskal-Wallis e Dunn. Os resultados revelaram que a variação do veículo associado ao MTA aumentou significativamente o tempo de presa, no entanto, não houve influência na alteração volumétrica (P>0,05) e na capacidade do cimento em manter o meio alcalino e liberar íons cálcio. Os cimentos manipulados com extratos em propilenoglicol apresentaram maior escoamento (P<0,05). Apenas o extrato da própolis agregou ao MTA efeito contra o Enterococcus faecalis após 24 e 48 horas (descontaminação dentinária e contato direto respectivamente) e contra a Cândida albicans após 10 horas (P<0,05). De acordo com as avaliações histológica e histomorfométrica dos implantes em tecidos subcutâneo e alveolar não foi constatada diferença significativa entre os grupos experimentais quando comparados com o grupo no qual o MTA foi manipulado...

The aim of this study was to evaluate the physicochemical, antimicrobial properties and biocompatibility of white MTA mixed with aqueous or propylene glycol extracts of Arctium lappa L., Casearia sylvestris Sw. and propolis. Among physicochemical tests were evaluated the setting time, flowability, pH, ion calcium release and volumetric change. To verify the antimicrobial effects were applied the methods of direct contact (Enterococcus faecalis and Candida albicans) and dentin decontamination by using the confocal laser scanning microscopy to verify the Enterococcus faecalis viability. To evaluate the biocompatibility were used 162 Wistar rats. Each animal received one alveolar and two subcutaneous implants. After the experimental periods of 15, 30 and 60 days were performed the microtomography, histological description and histomorphometric analyses. Additionally alveolar tissue samples were processed for the measurement of TNF-α e IL-10 cytokines by enzyme-linked immunosorbent assay (ELISA). The data were statistically analyzed by the ANOVA and Tukey or KruskalWallis and Dunns tests. The results revealed that the variation of the vehicle associated to MTA significantly increased its setting time, however did not influence the volumetric change (P>0,05) and the cement's ability to maintain the alkaline medium and ion calcium release. Cements mixed with propylene glycol extracts showed higher flowability (P<0,05). Only propolis extract added to MTA the effect against E. faecalis after 24 and 48 hours (dentin decontamination and direct contact respectively) and against Candida albicans after 10 hours (P<0,05). According to the histological and histomorphometric evaluation of the implants in subcutaneous and alveolar tissue was not observed significant differences between the experimental groups in comparison to the reference group (MTA was mixed with distilled water). The microtomography analysis and expression of TNF-α and IL-10 showed...

Shaping ability of Reciproc and TF Adaptive systems in severely curved canals of rapid microCT-based prototyping molar replicas

Objective: To evaluate the shaping ability of Reciproc and Twisted-File Adaptive systems in rapid prototyping replicas. Material and Methods: Two mandibular molars showing S-shaped and 62-degree curvatures in the mesial root were scanned by using a microcomputed tomography (μCT) system. The data were exported in the stereolitograhic format and 20 samples of each molar were printed at 16 µm resolution. The mesial canals of 10 replicas of each specimen were prepared with each system. Transportation was measured by overlapping radiographs taken before and after preparation and resin thickness after instrumentation was measured by μCT. Results: Both systems maintained the original shape of the apical third in both anatomies (P>0.05). Overall, considering the resin thickness in the 62-degree replicas, no statistical difference was found between the systems (P>0.05). In the S-shaped curvature replica, Reciproc significantly decreased the thickness of the resin walls in comparison with TF Adaptive. Conclusions: The evaluated systems were able to maintain the original shape at the apical third of severely curved mesial canals of molar replicas. .

Influence of bismuth oxide concentration on the pH level and biocompatibility of white Portland cement

Objectives: To investigate if there is a relation between the increase of bismuth oxide and the decrease of pH levels and an intensification of toxicity in the Portland cement. Material and Methods: White Portland cement (WPC) was mixed with 0, 15, 20, 30 and 50% bismuth oxide, in weight. For the pH level test, polyethylene tubes were filled with the cements and immersed in Milli-Q water for 15, 30 and 60 days. After each period, the increase of the pH level was assessed. For the biocompatibility, two polyethylene tubes filled with the cements were implanted in ninety albino rats (n=6). The analysis of the intensity of the inflammatory infiltrate was performed after 15, 30 and 60 days. The statistical analysis was performed using the Kruskal-Wallis, Dunn and Friedman tests for the pH level and the Kruskal-Wallis and Dunn tests for the biological analysis (p<0.05). Results: The results showed an increase of the pH level after 15 days, followed by a slight increase after 30 days and a decrease after 60 days. There were no significant statistical differences among the groups (p>0.05). For the inflammatory infiltrates, no significant statistical differences were found among the groups in each period (p>0.05). The 15% WPC showed a significant decrease of the inflammatory infiltrate from 15 to 30 and 60 days (p<0.05). Conclusions: The addition of bismuth oxide into Portland cement did not affect the pH level and the biological response. The concentration of 15% of bismuth oxide resulted in significant reduction in inflammatory response in comparison with the other concentrations evaluated. .

Influence of the Method in Root Canal Filling Using Active Lateral Compaction Techniques

The aim of this study was to evaluate, by stereomicroscopy and confocal laser microscopy, the influence of different lateral compaction methods for the obturation quality, as well as the time spent for the procedure. Thirty root canals of freshly extracted single-rooted human teeth were prepared with the ProTaper system up to F5 instrument and filled with gutta-percha and AH Plus sealer by the lateral compaction technique. The teeth were divided into 3 groups (n=10) in accordance with the method used for the lateral compaction, as follows: Manual, Mechanical and Ultrasonic. The sealers were stained with rhodamine B dye in a proportion of 0.1% per gram in weight to allow for the analysis under a confocal microscope. During the root filling procedure, the time spent was recorded with a stopwatch. The specimens were stored at 37 °C for 48 h, and then sectioned at 2, 4 and 6 mm from the apex. The percentage of gutta-percha, sealer and void areas were evaluated using a stereomicroscope and sealer penetration perimeter by confocal laser microscope. Statistical analyses were performed using the Kruskall-Wallis and Dunn tests (p<0.05). The mechanical method required a shorter time for the lateral compaction than the manual method (p<0.05). There were no significant differences (p>0.05) for the perimeter of the dentin with sealer penetration among all groups. The mechanical method showed a higher (p<0.05) percentage of gutta-percha and less sealer at the 4 mm section in comparison with the manual method. The ultrasonic group showed intermediate values. The void areas found in the root filling were similar (p>0.05) between the three methods. In conclusion, the fastest lateral compaction was achieved with the mechanical method, and all the methods showed void areas in the root filling.

O objetivo deste estudo foi avaliar a influência de diferentes técnicas de condensação lateral em relação a qualidade da obturação por meio de estereomicroscopia e microscopia confocal, bem com o tempo gasto para realizar o referido procedimento. Trinta canais radiculares de dentes humanos unirradiculares foram modelados com o sistema ProTaper, finalizando com o instrumento F5. Em seguida os canais foram obturados com guta percha e cimento AH Plus por meio da técnica de condensação lateral. Os espécimes foram divididos em 3 grupos (n=10) de acordo com o método de condensação lateral utilizado, sendo: Manual, Mecânico, Ultrassônico. Os cimentos foram manipulados com rodamina B na proporção de 0.1% de peso para permitir a análise com microscopia confocal. O tempo gasto para realizar cada procedimento de obturação foi registrado com o uso de um cronômetro. Os espécimes foram armazenados a 37 °C durante 48 h, para em seguida serem seccionados a 2, 4 e 6 mm a partir do ápice radicular. A porcentagem da área de guta percha, cimento e vazios foram avaliados com estereomicroscópio. A penetração de cimento foi avaliada por meio de microscópio confocal. A análise estatística foi realizada utilizando os testes de Kruskall-Wallis e Dunn (P < 0.05). O método mecânico exigiu menos tempo para realizar a condensação lateral em comparação com o método manual (p<0.05). Não foi encontrada diferença (p>0.05) em relação ao perímetro de penetração de cimento nos túbulos dentinários entre todos os grupos avaliados. O método mecânico apresentou maior (p<0.05) porcentagem de guta percha e menos cimento no nível de 4 mm quando comparado com o método manual. O grupo do ultrassom apresentou resultados intermediários. Áreas de vazios encontradas foram similares (p>0.05) entre os grupos. Foi possível concluir que o método mecânico foi mais rápido para a técnica de condensação lateral, mas todos os métodos de obturação estudados apresentaram espaços vazios na massa obturadora.