Laboratory study of tissue repair of resin-based endodontic sealers in critical surgical defects.

OBJECTIVE: Filling materials should be restricted to the root canal space. However, sometimes it is impossible to control the apical extrusion, in this case, the fate of the filling material and the result of the treatment will depend on its physicochemical properties and biocompatibility. To evaluate the tissue response and bone repair capacity of endodontic sealers that were implanted in the calvaria of Wistar rats, forming the groups (n=16): AH Plus and Sealer Plus, compared to the clot group. METHODOLOGY: On days 30 and 60, the animals were euthanized, the calvaria was removed and processed for hematoxylin-eosin, immunohistochemistry for collagen type I, Picrosirus red and microtomographic analysis. Data were subjected to ANOVA and Tuckey tests (p<0.05). RESULTS: At 30 days, all groups showed an intense inflammatory reaction (p>0.05). At 60 days, the AH Plus and Sealer Plus maintained an intense inflammatory infiltrate compared to the clot group (p<0.05). We observed immunopositive areas for type I collagen in all groups at 30 days and 60 days (p>0.05). We observed more red collagen fibers for the Sealer Plus compared to the clot group at 30 days (p<0.05). Considering the total fibers, the clot group at 30 days compared to 60 days after surgery showed an increase in the amount of matrix (p<0.05). There were no statistical differences between groups for green and yellow fibers (p>0.05). Regarding morphometric parameters, at 30 days, the newly formed bone volume and number of bone trabeculae were higher in the groups with sealers compared to the clot group (p<0.05). At 60 days, AH Plus and Sealer Plus showed greater bone neoformation compared to the clot group (p<0.05). CONCLUSIONS: Despite AH Plus and Sealer Plus induced an intense inflammatory reaction, they can be considered biocompatible materials, since they allowed bone repair.

Laboratory study of tissue repair of resin-based endodontic sealers in critical surgical defects

Abstract Filling materials should be restricted to the root canal space. However, sometimes it is impossible to control the apical extrusion, in this case, the fate of the filling material and the result of the treatment will depend on its physicochemical properties and biocompatibility. Objective To evaluate the tissue response and bone repair capacity of endodontic sealers that were implanted in the calvaria of Wistar rats, forming the groups (n=16): AH Plus and Sealer Plus, compared to the clot group. Methodology On days 30 and 60, the animals were euthanized, the calvaria was removed and processed for hematoxylin-eosin, immunohistochemistry for collagen type I, Picrosirus red and microtomographic analysis. Data were subjected to ANOVA and Tuckey tests (p<0.05). Results At 30 days, all groups showed an intense inflammatory reaction (p>0.05). At 60 days, the AH Plus and Sealer Plus maintained an intense inflammatory infiltrate compared to the clot group (p<0.05). We observed immunopositive areas for type I collagen in all groups at 30 days and 60 days (p>0.05). We observed more red collagen fibers for the Sealer Plus compared to the clot group at 30 days (p<0.05). Considering the total fibers, the clot group at 30 days compared to 60 days after surgery showed an increase in the amount of matrix (p<0.05). There were no statistical differences between groups for green and yellow fibers (p>0.05). Regarding morphometric parameters, at 30 days, the newly formed bone volume and number of bone trabeculae were higher in the groups with sealers compared to the clot group (p<0.05). At 60 days, AH Plus and Sealer Plus showed greater bone neoformation compared to the clot group (p<0.05). Conclusions Despite AH Plus and Sealer Plus induced an intense inflammatory reaction, they can be considered biocompatible materials, since they allowed bone repair.

Antibióticos potencializam a ação antimicrobiana de cimentos endodônticos, em diferentes períodos, após a presa / Antibiotics increase the antimicrobial action of endodontic seal-ers, in different periods, after setting time

O objetivo do presenteestudo foi avaliar a atividade antibacteriana dos cimentos endodôn-ticos MTA Fillapex, Sealapex, Sealer 26 e Endofill puros e acrescidos de amoxicilina e ci-profloxacina frente a duas linhagens ATCC de Enterococcus faecalis (ATCC 29212 e ATCC 4083). Os testes foram realizados pela técnica de difusão radial dos cimentos aplicados di-retamente no ágar e impregnados em discos de papel e pelo teste de contato direto. Para a análise estatística, utilizaram-se os testes de ANOVA e Tukey com nível de significância de 5%. Os resultados mostraram que pela técnica da difusão radial, considerando os cimentos puros, o Sealapex foi o único que apresentou halos de inibição frente às duas linhagens. Já quando da associação de amoxicilina e ciprofloxacina, o MTA Fillapex revelou os melhores halos de inibição para as duas linhagens. Todos os cimentos tiveram a ação potencializada pela adição dos antibióticos (p<0,05). Pela técnica de difusão dos cimentos impregnados em discos de papel, o cimento Sealapex puro fresco demonstrou atividade antimicrobiana em todas as variáveis de tempo. Quando acrescidos dos antibióticos, todos os cimentos ti-veram a ação antimicrobiana potencializada pelas drogas, em todas as variáveis de tempo. Esse mesmo resultado foi observado na técnica do contato direto dos cimentos com ambas as linhagens. A atividade antibacteriana, frente ao E. faecalis, dos cimentos MTA Fillapex, Endofill, Sealer e Sealapex, acrescidos dos antibióticos amoxicilina e ciprofloxacina, foi potencializada mesmo após um longo período da presa dos cimentos.

The objective of this study was to evaluate the antibacterial activity of different endodon-tic cements (MTA Fillapex, Sealapex, Sealer 26, and Endofill), both pure and mixed with 5% of amoxicillin or ciprofloxacin, against two strains of Enterococcus faecalis (ATCC 29212 and ATCC 4083). Bacterial susceptibility testing was conducted by radial diffusion methods and direct contact test after different periods. Data were subjected to ANO-VA and Tukey test with a significance level of 5%. Sealapex was the only pure sealer to promote the inhibition of bacterial growth against both strains in different experimental periods. However, all cements present an increase in antibacterial activity by the addition of antibiotics (p<0.05). MTA Fillapex and Sealapex associated with amoxicillin promoted increased values for bacterial growth against ATCC 29212 and ATCC 4083 in comparison to other groups (p<0.001), including extended periods after setting time. The association of antibiotic agents increased the antibacterial effect of the evaluated sealers against the strains of E. faecalis.

Physical Properties, Antimicrobial Activity and In Vivo Tissue Response to Apexit Plus.

We investigated the physical properties, antimicrobial activity, and tissue reaction to Apexit Plus in comparison to Sealapex. Flow, radiopacity, setting time, and solubility were evaluated in each material. The antimicrobial activity against Enterococcus faecalis was performed. Polyethylene tubes containing Apexit Plus or Sealapex, and without material (control group) were implanted into the subcutaneous tissue of rats. At 7, 15, 30, and 60 days of implantation, the specimens were paraffin-embedded and the number of inflammatory cells (ICs) and the amount of birefringent collagen (BC) were quantified. The von Kossa reaction followed by immunohistochemistry for detection of alkaline phosphatase (ALP) was also performed. Statistical analysis was performed with ANOVA and Tukey test (p ≤ 0.05). The flow value of Apexit Plus was greater than Sealapex, whereas the radiopacity (3.44 mm Al) was lower than Sealapex (6.82 mm Al). Apexit Plus showed lower solubility and shorter initial and final setting (p 0.0001), whereas the antimicrobial activity was significantly greater than Sealapex. Although the number of ICs was higher in Apexit Plus (p = 0.0009) at 7 days, no significant difference was detected between Apexit Plus and Sealapex at 15, 30, and 60 days. All groups showed higher values for BC in the capsules over time. ALP-immunolabelled cells were observed, mainly around von Kossa-positive structures, either in the capsules of Apexit Plus or Sealapex. Therefore, our results revealed that Apexit Plus exhibited a greater effectiveness against Enterococcus faecalis and better physical properties than Sealapex, except for the radiopacity. In vivo findings indicate that Apexit Plus is biocompatible and presents potential bioactivity in the subcutaneous tissue.

Uso do ultrassom na otimização do tratamento endodôntico: relato de caso / Use of ultrasonics to optimize endodontic treatment: case report

Objetivo: o objetivo do presente relato de caso foi demonstrar o emprego do ultrassom em diversas etapas do tratamento endodôntico de um segundo molar inferior com anatomia em forma de C, possibilitando um aumento na previsibilidade no tratamento em dentes com complexidades anatômicas. Relato de caso: paciente do sexo masculino, relatou sensibilidade dolorosa no lado direito inferior da face. O exame clínico mostrou ausência de vitalidade pulpar, e o exame radiográfico detectou a presença de lesão cariosa no dente #47, lesão periapical e uma anatomia em forma de C. Assim, o tratamento de escolha foi a necropulpectomia. Após abertura coronária, foi realizado o refinamento da câmara pulpar e das embocaduras dos canais, com ponta de ultrassom. O preparo biomecânico foi realizado com instrumento Reciproc 25.08 e Mtwo 40.04, sendo a agitação final do hipoclorito de sódio e do EDTA realizada com a ponta ultrassônica Irrisonic. A medicação intracanal empregada foi a pasta de hidróxido de cálcio. Após 15 dias, a medicação foi removida por meio de irrigação ultrassônica passiva, e os canais foram secos com pontas de papel absorvente esterilizadas. A obturação dos canais foi realizada com o cimento AH Plus, o qual foi inserido com espiral de Lentulo #40 e, em seguida, agitado por 1 minuto com ultrassom. Então, a técnica de obturação híbrida de Tagger foi realizada. Conclusão: o controle radiográfico após 1 ano e 8 meses mostrou o reparo total da lesão periapical, demonstrando que uso o ultrassom nas diversas etapas da terapia endodôntica pode contribuir para uma maior previsibilidade do tratamento (AU).

The aim of this case report was to describe the use of ultrasonic in several endodontics steps during root canal treatment of second C-shaped mandibular molar, favoring more predictable outcome of endodontic treatment of teeth with complex anatomy. A male patient reported painful symptoms on the right and lower side of the face. Clinical examination revealed absence of pulp vitality of tooth 47 and the radiographic examination showed carious lesion, apical periodontitis and C-shaped anatomy. Therefore, the necropulpectomy treatment was selected. After the coronal access, an ultrasonic tip was used to remove the irregularities of the pulp chamber. The root canal preparation was performed using Reciproc 25.08 and Mtwo 40.04 and a final passive ultrasonic irrigation of the sodium hypochlorite and EDTA was performed with Irrisonic tip. Calcium hydroxide paste was used as intracanal dressing, which was introduced by Lentulo #40 and ultrasonic agitated. After 15 days, a passive ultrasonic irrigation was performed to remove the intracanal dressing and the canals were dried with sterilized paper points. The root filling was performed with AH Plus sealer, which was introduced by Lentulo #40 in a electric motor at 350 rpm and ultrasonic agitated during 1 minute. Then, the hybrid Tagger technique was performed to root canal filling. The radiographic examination showed the suitable isthmus and lateral canals filling. After 1 year and 8 months, the radiographic examination revealed complete apical healing, showing that the use of ultrasonic in several steps of endodontic treatment can favor a more predictable outcomes (AU).

Avaliação in vitro da atividade antifúngica da pasta de hidróxido de cálcio associada a diferentes fármacos, frente à Candida albicans / In vitro evaluation of antifungal activity of calcium hydroxide paste mixed to different drugs, against Candida albicans

Introdução: a frequência de micoses invasivas causadas por patógenos fúngicos oportunistas tem aumentado significativamente nas últimas décadas. Entre os principais agentes etiológicos de micoses oportunistas está a Candida albicans. Essa levedura apresenta vários fatores de virulência importantes para produção de doença. Alguns estudos têm demonstrado que C. albicans coloniza canais radiculares e túbulos dentinários. O espectro de atividade antimicrobiana do curativo de hidróxido de cálcio deve incluir essa levedura. Objetivos: o objetivo da presente pesquisa foi determinar a suscetibilidade in vitro de quatro linhagens de C. albicans coletadas da cavidade oral e uma estirpe padrão ATCC 10231 a pastas de hidróxido de cálcio associadas a drogas antifúngicas, antibióticas e anti-inflamatórias. A eficiência das pastas de Ca(OH)2 associadas às drogas sobre as leveduras foram analisadas pelo método da difusão radial e, também, pela técnica do contato direto com os medicamentos. Os dados foram analisados pelo teste de Kruskal-Wallis e o pós-teste de Dunn, para indicar as diferenças entres os grupos, com um nível de significância de 5%. Resultados: todas as medicações antifúngicas potencializaram a ação das pastas de hidróxido de cálcio contra a Candida albicans. Conclusões: a associação de medicações antifúngicas às pastas de Ca(OH)2 pode ser uma alternativa como medicação intracanal. (AU)

Introduction: the frequency of invasive mycoses caused by opportunistic fungal pathogens has increased significantly in the last decades. Among the main etiological agents of opportunistic mycoses is Candida albicans. This yeast has several important virulence factors for producing disease. Some studies have demonstrated that C. albicans colonized root canals and dentinal tubules. The spectrum of antimicrobial activity of calcium hydroxide dressing should include this yeast. Objectives: the aim of the present study was to determine the in vitro susceptibility of four C. albicans strains collected from the oral cavity and a standard strain ATCC 10231 to calcium hydroxide paste associated with antifungal, antibiotic and anti-inflammatory drugs. The efficiency of the Ca(OH)2 paste associated with the drugs on the yeasts was analyzed by the radial diffusion method and also by the direct contact method. Data were analyzed by Kruskal Wallis test and the Dunn post-test were used to indicate the differences between the groups with a significance level of 5%. Results: all antifungal drugs increased the action of the calcium hydroxide pastes against Candida albicans. Conclusions: the association of antifungals with Ca(OH)2 may be considered for use as intracanal medicaments (AU).

Atividade antimicrobiana do cimento à base de silicato de cálcio acrescido de antibióticos, testada pelos métodos de difusão radial e concentração inibitória mínima / Antimicrobial activity of calcium silicate-based sealer containing antibiotics, tested by means of radial diffusion and minimum inhibitory concentration

Introdução: a substituição do MTA pelo cimento Portland tem sido recomendada pela semelhança em suas composições e propriedades físicas e biológicas. A adição de um antibiótico ao cimento promoveria vantagens clínicas, desde que esse fosse liberado antes e após a presa do cimento. Objetivo: avaliar a atividade antimicrobiana, pelos métodos da difusão e concentração inibitória mínima (CIM), do cimento Portland puro e acrescido de radiopacificador, adicionado de amoxicilina e ciprofloxacina, frente a cinco microrganismos: S. aureus, P. aeruginosa, E. coli, E. faecalis e C. albicans. Métodos: no teste de difusão, foram utilizadas 30 placas de Petri com ágar, escavadas com poços onde foram introduzidos os cimentos imediatamente após a manipulação e após presa de 24h. Para o teste de CIM, foram preparados 120 tubos de ensaio, contendo 10mL de caldo BHI, divididos em quatro grupos. Cada grupo foi semeado com um inóculo fresco de cada microrganismo, separadamente. Os tubos foram incubados em estufa a 37°C e a turbidez foi avaliada após 24h. Os resultados foram avaliados pela análise de variância ANOVA e a comparação dos grupos, pelo teste de Tukey, com significância de 5%. Resultados: o cimento Portland apresentou atividade antimicrobiana apenas contra C. albicans. A amoxicilina apresentou um tênue efeito antibacteriano, enquanto a ciprofloxacina inibiu o crescimento bacteriano em todas as concentrações testadas. Conclusão: a adição da ciprofloxacina ao cimento Portland a fim de incrementar a atividade antimicrobiana parece segura; entretanto, os resultados não sustentam sua aplicação clínica, sendo necessários novos estudos.

Filling of simulated lateral canals with gutta-percha or thermoplastic polymer by warm vertical compaction.

The aim of this study was to evaluate the ability of gutta-percha and a thermoplastic synthetic polymer (Resilon) to fill simulated lateral canals, using warm vertical compaction. Forty-five single-rooted human teeth were prepared using the rotary crown-down technique. Artificial lateral canals were made at 2, 5, and 8 mm from the working length (WL) in each root. The specimens were divided into three groups (n = 15), according to the filling material: Dentsply gutta-percha (GD), Odous gutta-percha (GO), and Resilon cones (RE). The root canals were obturated using warm vertical compaction, without endodontic sealer. The specimens were subjected to a tooth decalcification and clearing procedure. Filling of the lateral canals was analyzed by digital radiography and digital photographs, using the Image Tool software. The data were subjected to the Kruskal-Wallis and Dunn tests at 5% significance. RE had the best filling ability in all root thirds (p < 0.05), with similar results for GO in the coronal third. In the middle and apical thirds, GD and GO had similar results (p > 0.05). Resilon may be used as an alternative to gutta-percha as a solid core filling material for use with the warm vertical compaction technique. The study findings point to the potential benefit of the warm vertical compaction technique for filling lateral canals, and the study provides further information about using Resilon and gutta-percha as materials for the warm vertical compaction technique.

Filling of simulated lateral canals with gutta-percha or thermoplastic polymer by warm vertical compaction

The aim of this study was to evaluate the ability of gutta-percha and a thermoplastic synthetic polymer (Resilon) to fill simulated lateral canals, using warm vertical compaction. Forty-five single-rooted human teeth were prepared using the rotary crown-down technique. Artificial lateral canals were made at 2, 5, and 8 mm from the working length (WL) in each root. The specimens were divided into three groups (n = 15), according to the filling material: Dentsply gutta-percha (GD), Odous gutta-percha (GO), and Resilon cones (RE). The root canals were obturated using warm vertical compaction, without endodontic sealer. The specimens were subjected to a tooth decalcification and clearing procedure. Filling of the lateral canals was analyzed by digital radiography and digital photographs, using the Image Tool software. The data were subjected to the Kruskal-Wallis and Dunn tests at 5% significance. RE had the best filling ability in all root thirds (p < 0.05), with similar results for GO in the coronal third. In the middle and apical thirds, GD and GO had similar results (p > 0.05). Resilon may be used as an alternative to gutta-percha as a solid core filling material for use with the warm vertical compaction technique. The study findings point to the potential benefit of the warm vertical compaction technique for filling lateral canals, and the study provides further information about using Resilon and gutta-percha as materials for the warm vertical compaction technique.

Avaliação das propriedades físicas, químicas e biológicas do cimento Portland associado á radiopacificadores micro e nanoparticulados / Evaluation of physicochemical and biological properties of Portland cement associated to micro and nanoparticulated radiopacifiers

Objetivo: Avaliar as propriedades físicas, químicas e biológicas do cimento Portland (CP) associado a diferentes radiopacificadores (óxido de zircônio - OZr e óxido de nióbio - ONb) micro e nanoparticulados. Metodologia: Para isso, os grupos experimentais foram divididos em: Capítulo 1 - CP, CP+20% de óxido de bismuto (OB), CP+30% OZrmicro e CP+30% OZrnano; Capítulo 2 - CP+30% ONbmicro, CP+30% ONbnano e MTA-Angelus. Todos os materiais foram submetidos aos testes de radiopacidade, tempo de presa, pH e liberação de íons cálcio. Além disso, nos materiais do capítulo 1 foi realizado o teste de resistência à compressão após 24 horas e 21 dias. A reação tecidual provocada pelos materiais foi investigada por meio de análises morfológica, morfométrica (densidade numérica de células inflamatórias, CI) e imuno-histoquímica (número de células imunopositivas à interleucina-6, IL-6) da cápsula formada após 7, 15, 30 e 60 dias de implantação no subcutâneo dorsal. O método von Kossa, para detecção de estruturas calcificadas, também foi realizado. Resultados: Capítulo 1 ­ Os materiais testados apresentaram pH alcalino e liberação de íons cálcio após 1, 7, 14 e 28 dias. Os materiais CP+OB, CP+OZrmicro e CP+OZrnano apresentaram valores de radiopacidade estatisticamente superiores ao CP e similares entre si. O CP+OZr micro e o CP+OZr nano exibiram tempos de presa maiores do que CP (p≤0,05). O CP apresentou valor de resistência à compressão, após 24 horas e 21 dias, maior do que os materiais, porém, a adição de OZr promoveu médias estatisticamente superiores quando comparado ao CP+OB. Em todos os grupos, verificou-se redução significante no número de CI e de células imunopositivas à IL-6 aos 15, 30 e 60 dias em comparação à 7 dias. O número de CI e de células imunomarcadas à IL-6 nos materiais contendo OZr foi significantemente menor do que o CP+OB em todos os períodos experimentais. Estruturas von Kossa positivas foram observadas na cápsula adjacente aos materiais implantados em todos os períodos. Capítulo 2 - O MTA apresentou maior radiopacidade quando comparado aos grupos com ONb. O ONb aumentou o tempo de presa inicial dos materiais se comparados ao MTA. Os materiais avaliados apresentaram pH alcalino e liberaram íons cálcio. Em todos os grupos, foi verificada uma redução gradativa e significante no número de CI e IL-6 a partir dos 7 dias. Aos 7 e 60 dias, o CP+ONb micro apresentou as menores médias para o número de CI e células imunopositivas à IL-6. Em todos os períodos, as cápsulas formadas em resposta aos cimentos CP+ONb micro e o CP+ONb nano exibiram médias de densidade numérica de células inflamatórias e de células IL-6 positivas inferiores ou similares ao MTA. Estruturas von Kossa positivas foram observadas na cápsula adjacente aos materiais implantados em todos os períodos. Conclusão: Capítulo 1 - Os resultados mostraram que o óxido de zircônio microparticulado e nanoparticulado favorece as propriedades físicas, químicas e biológicas do CP em comparação ao óxido de bismuto. Capítulo 2 - O CP+ONbmicro e o CP+ONbnano são materiais biocompatíveis com propriedades físicas e químicas adequadas, similares ao MTAAngelus

Objective: The aim of this study was to evaluate the effect of different micro e nanoparticulated radiopacifiers (zirconium oxide ­ ZrO and niobium oxide - NbO) on the physicochemical and biological properties of Portland cement (PC). Methods: The experimental groups were divided in: Chapter 1 - PC, PC+20% bismuth oxide (BO), PC+30% ZrOmicro e PC+30% ZrOnano; Chapter 2 - PC+30% NbOmicro, PC+30% NbOnano and MTA-Angelus. All materials were submitted to the tests of radiopacity, setting time, pH and calcium ion release. Besides, in the materials of chapter 1, the test of compressive strength after 24 hours and 21 days was performed. Moreover, tissue reaction promoted by all materials was evaluated in rat subcutaneous. In each rat, two polyethylene tubes filled with materials were implanted into dorsal subcutaneous. Empty tubes were used as control. After 7, 15, 30 and 60 days, the specimens were fixed and embedded in paraffin. In the HE-stained sections, the number of inflammatory cells (IC) in the capsule was obtained. Moreover, detection of interleukin-6 (IL-6) by immunohistochemistry and number of IL-6 immunolabeled cells were carried out. The von Kossa method was also performed. The differences among the groups were subjected to ANOVA with a significance level of 5%. Results: Chapter 1 ­ All materials presented an alkaline pH and released calcium ions after 1, 7, 14 and 28 days. The PC+BO, PC+ZrOmicro and PC+ZrOnano exhibited radiopacity values statistically superior than PC. The PC+ZrOmicro and PC+ZrOnano presented setting times higher than PC (p≤0.05). After 24 hours and 21 days, the PC showed compressive strength value significantly superior to the other materials. A higher compressive strength in the PC+ZrO (micro and nano) was found compared to PC+BO. In all groups, significant reduction in the number of IC and IL-6 immunolabeled cells was verified from 7 days. Furthermore, the number of IC and IL-6 positive cells in the CP+ZrO was significantly reduced in comparison to PC+BO in all periods. von Kossa-positive structures were observed in the capsule adjacent to implanted materials. Chapter 2 - The MTA presented superior radiopacity when compared to the groups with NbO. The NbO increased the initial setting time of the materials in comparison to the MTA. The evaluated materials showed alkaline pH and were able to release calcium ion. In all groups, a significant and gradual reduction in the number of IC and IL-6 immunopositive cells was verified from 7 to 15, 30 and 60 days. At 7 and 60 days, the PC+NbOmicro presented number of IC and of IL-6 immunopositive cells inferior than the other materials. In all periods, the capsules adjacent to the MTA exhibited number of IC and of IL-6 immunopositive cells similar or superior than PC+NbOmicro and PC+NbOnano. von Kossa-positives structures were seen in the capsule adjacent to the implanted materials in all periods. Conclusion: Chapter 1 ­ The results revealed that ZrO microparticulated and nanoparticulated exhibits better physicochemical and biological properties in comparison to BO. Chapter 2 ­ The PC+NbOmicro and PC+NbO presented satisfactory physicochemical and biological properties, similar to the MTA

Solvent capacity of different substances on gutta-percha and Resilon.

The aim of this study was to evaluate the effectiveness of 3 solvents (eucalyptol, orange oil, and xylol) on 2 types of gutta-percha (conventional and thermoplastic) and Resilon. Specimens (10 mm diameter x 1 mm thick; n=7 per condition) were prepared and maintained at 37 degrees C for 48 h. Each specimen was weighed on a precision scale every 24 h until its mass was stable, at which time the initial mass was determined. Specimens (n=7) were then immersed in the solvent solutions and, after 48 h at 37 degrees C, they were reweighed at 24- h intervals, until stabilization (final mass). The difference between the final and the initial mass determined the solvent capacity of each solvent. Data were subjected to analysis of variance and Tukey's test at 5% significance level. The results demonstrated that xylol was the most effective, especially on conventional gutta-percha and Resilon (p<0.05). Eucalyptol and orange oil were more effective on thermoplastic gutta-percha than the other materials (p<0.05). It was concluded that all evaluated substances presented solvent action, but xylol was the most effective on both gutta-percha or Resilon.

Solvent capacity of different substances on gutta-percha and Resilon

The aim of this study was to evaluate the effectiveness of 3 solvents (eucalyptol, orange oil, and xylol) on 2 types of gutta-percha (conventional and thermoplastic) and Resilon. Specimens (10 mm diameter x 1 mm thick; n=7 per condition) were prepared and maintained at 37ºC for 48 h. Each specimen was weighed on a precision scale every 24 h until its mass was stable, at which time the initial mass was determined. Specimens (n=7) were then immersed in the solvent solutions and, after 48 h at 37ºC, they were reweighed at 24- h intervals, until stabilization (final mass). The difference between the final and the initial mass determined the solvent capacity of each solvent. Data were subjected to analysis of variance and Tukey's test at 5 percent significance level. The results demonstrated that xylol was the most effective, especially on conventional gutta-percha and Resilon (p<0.05). Eucalyptol and orange oil were more effective on thermoplastic gutta-percha than the other materials (p<0.05). It was concluded that all evaluated substances presented solvent action, but xylol was the most effective on both gutta-percha or Resilon.

O objetivo deste estudo foi avaliar a efetividade de 3 solventes em 2 tipos de guta-percha e no Resilon. Os materiais avaliados foram: guta convencional (Endo points), guta termoplastificada (Endo points TP) e cones de Resilon (RE). Amostras circulares medindo 10 mm de diâmetro e 1 mm de espessura foram preparadas, sendo mantidas a 37°C por 48 h. Cada amostra, com o anel metálico, foi pesada em uma balança de precisão a cada 24 h até estabilização da massa, quando a massa inicial era determinada. As amostras (n=7) foram imersas, então, nas soluções solventes avaliadas (eucaliptol, óleo de laranja, e xilol). Após 48 h a 37ºC, as amostras foram pesadas outra vez a cada 24 h, até a estabilização (massa final). A diferença entre a massa final e inicial determinou a capacidade solvente de cada material. Os dados foram submetidos à análise de variância em nível de significância de 5 por cento e teste de Tukey. Os resultados demonstraram que o xylol foi mais eficaz solvente, especialmente na guta convencional e no Resilon (p<0,05). O eucaliptol e o óleo de laranja foram mais eficazes sobre a guta thermoplastificada em relação aos outros materiais obturadores (p<0,05). Conclui-se que todas as substâncias testadas apresentam ação solvente, contudo, o xilol foi o mais efetivo sobre a guta-percha ou Resilon.

Efetividade de quatro solventes sobre diferentes cimentos endodônticos / Effectiveness of four solvents on different endodontic sealers

Este estudo teve como objetivo avaliar a capacidade solvente de quatro solventes sobre cimentos obturadores. Os cimentos avaliados foram: Acroseal, AH Plus, Epiphany, Endomethasone N e Sealer 26. Foram confeccionados corpos-de-prova circulares com 10 mm de diâmetro e 1 mm de espessura para cada cimento. Cada corpo-de-prova foi pesado em balança de precisão até a estabilização da massa, quando a massa inicial foi determinada. Em seguida, os corpos-de-prova (n=07) foram imersos por 10 minutos nas soluções solventes avaliadas: eucaliptol, óleo de laranja (citrol), xilol e uma solução solvente experimental à base de tetracloroetileno. Depois de 48 h em estufa a 37ºC, foram realizadas novas pesagens a cada 24 h, até a estabilização (massa final). A diferença da massa final e inicial determinou a capacidade solvente. Os dados obtidos foram submetidos à análise de variância com 5% de significância e teste de Tukey. O cimento Endomethasone N foi o material mais solubilizado pelos solventes estudados. O cimento que apresentou menor solubilização foi o AH Plus, seguido pelo Acroseal, exceto no grupo eucaliptol, onde o Sealer 26 apresentou maior solubilização que o Acroseal. O cimento Epiphany, embora com baixa solubilização, foi o que apresentou maior ação solvente após o Endomethasone N. Conclui-se que o cimento à base de óxido de zinco e eugenol é o mais solubilizado pelos solventes avaliados, destacando-se o xilol.

The aim of this study was to evaluate the solvent capacity of four solvents on endodontic sealers. The evaluated sealers were: Acroseal, AH Plus, Epiphany, Endomethasone N, and Sealer 26. Standardized specimens (10 X 1 mm) were made. Each specimen was weighted using a precision balance until the weight become stable, when the initial weight was established. Then, the specimens (n=7) were immersed for 10 minutes in each evaluated solvent: eucalyptol, orange oil (citrol), xylol and an experimental solvent solution based on tetrachloroethylene. After 48 h in stove at 37ºC, the weight of the specimens was measured at each 24 h until the weight become stable again (final weight). The difference between the final and initial weight determined the solvent action. The obtained data were submitted to the Analysis of Variance with 5% of significance and Tukey test. The Endomethasone N sealer was the material more soluble by the studied solvents. The less soluble sealer was AH Plus, followed by Acroseal, except for the eucalyptol, were Sealer 26 showed be less soluble than Acroseal. The Epiphany sealer, although with low solubilization, was the sealer with more solvent action after Endomethasone N. In conclusion, the sealer based on zinc-oxide and eugenol was the most soluble by the evaluated solvents, with xylol showing more effectiveness.

Radiopacity evaluation of root-end filling materials by digitization of images

The purpose of this study was to evaluate the radiopacity of 5 root-end filling materials (white MTA-Angelus, grey MTA-Angelus, IRM, Super EBA and Sealer 26). Five specimens (10 mm diameter X 1 mm thickness) were made from each material and radiographed next to an aluminum stepwedge varying in thickness from 2 to 16 mm. Radiographs were digitized and the radiopacity of the materials was compared to that of the aluminum stepwedge using VIXWIN 2000 software in millimeters of aluminum (mm Al). Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. Radiopacity values varied from 3 mm Al to 5.9 mm Al. Sealer 26 and IRM presented the highest radiopacity values (p<0.05), while white/grey MTA and Super EBA presented the lowest radiopacity values (p<0.05). The tested root-end filling materials presented different radiopacities, white/grey MTA and Super EBA being the least radiopaque materials.