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La preparación de la cavidad de acceso es el primer paso y un requisito esencial, para la instrumentación y obturación de los conductos radiculares durante el tratamiento endodóntico. El objetivo del presente estudio fue comparar la resistencia a la fractura in vitro de premolares con cavidad de acceso tradicional (CAT), cavidad de acceso conservador (CAC) y cavidad de acceso ultraconservador (CAU). Esta fue una investigación transversal, prospectiva y experimental pura. Se realizó con 40 segundos premolares superiores, divididos en 4 grupos. Todas las muestras fueron desinfectadas y almacenadas en recipientes con suero fisiológico al 0,9 %. Al primer grupo se designó como el control, al segundo grupo CAT, al tercer grupo CAC y al cuarto grupo CAU. Se realizaron todos los accesos endodónticos con una pieza de mano de alta velocidad con refrigeración respetando el protocolo de cada uno de los diseños, posterior a ello se realizó el tratamiento endodóntico y restauración de los especímenes. Una vez preparadas todas las muestras, estas fueron sometidas a una prueba de fatiga en una máquina de ensayo universal y los resultados se registraron en Newtons. La prueba estadística usada fue ANOVA con un nivel de significancia de 5 %. Las CAT obtuvieron el menor valor de resistencia a la fractura en comparación con el grupo control. Sin embargo, no se observaron diferencias estadísticamente significativas entre los grupos CAT, CAC Y CAU. Entre los grupos CAC y CAU, no se encontraron diferencias estadísticamente significativas en comparación con el grupo control.
The preparation of the access cavity is the first step and an essential requirement for the instrumentation and obturation of the root canals during endodontic treatment. The objective of the present study was to compare the in vitro fracture resistance of premolars with traditional access cavity (CAT), conservative access cavity (CAC) and ultraconservative access cavity (CAU). This was a cross-sectional, prospective and pure experimental research. It was carried out with 40 upper second premolars, divided into 4 groups. All samples were disinfected and stored in containers with 0.9 % physiological saline. The first group was designated as the control, the second group CAT, the third group CAC and the fourth group CAU. All endodontic accesses were carried out with a high-speed handpiece with refrigeration, respecting the protocol of each of the designs, after which the endodontic treatment and restoration of the specimens was carried out. Once all the samples were prepared, they were subjected to a fatigue test in a universal testing machine and the results were recorded in Newtons. The statistical test used was ANOVA with a significance level of 5 %. The CAT obtained the lowest fracture resistance value, presenting statistically significant differences with the control group. However, no statistically significant differences were observed between the CAT, CAC, and CAU groups. Furthermore, between the CAC and CAU groups, no statistically significant differences were found compared to the control group.
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Aim: to evaluate the surface roughness and fracture resistance of complete dentures made using heat-cured polymethyl methacrylate (PMMA) resin manufactured by conventional technique & digital complete dentures manufactured by additive manufacturing technique. Materials and Methods: A total of 24 complete dentures were made (n=24), 12 dentures were made using heat-cured polymethyl methacrylate (PMMA) resin manufactured by the conventional methods. 12 dentures were designed by Exocad software program & constructed using additive manufacturing technique. Surface roughness was evaluated using optical profilometry. Fracture resistance was evaluated using universal testing machine. Data were analysed using unpaired t-test where α = 0.05. Results: There was no statistically significant difference found between the two groups when comparing the surface roughness values (P=0.5137). Conventional PMMA dentures showed mean (2.52± 0.14 µm), while 3D-printed dentures showed mean (2.59± 0.38 µm). However, regarding the fracture resistance, there was statistically significant difference found between the two groups (P(P<0.5), the conventional PMMA dentures showed higher mean (572.49± 13.07 N), while the digital dentures showed lesser mean with (202.51 ± 10.35 N). Conclusion: Conventional PMMA dentures and 3D-printed dentures had similar surface roughness. However conventional PMMA dentures had better fracture resistance when compared to 3D-printed dentures
Assuntos
Propriedades de Superfície , Qualidade, Acesso e Avaliação da Assistência à Saúde , Processos Fotoquímicos , MétodosRESUMO
Objective@#To evaluate the impact of ultra-high-molecular-weight polyethylene (UHMWPE)-Ribbond fibers, when combined with different restorative materials, on fracture resistance and marginal adaptation of isolated primary molar defects, to provide a reference for clinical practice.@*Methods@#This study was approved by the Ethics Review Committee. A total of 72 extracted primary molars with complete crowns were collected, and 66 primary molars were randomly assigned as experimental groups for the fracture resistance and microleakage tests. The molars were divided into six groups (n = 11) based on the type of restorative materials and the application of Ribbond fibers: Group A1, 3M Filtek Z250 + Ribbond; Group A2, 3M Filtek Z250; Group B1, Beautifil II LS + Ribbond; Group B2, Beautifil II LS; Group C1, 3M Filtek Bulk Fill + Ribbond; and Group C2, 3M Filtek Bulk Fill. Groups A1, B1 and C1 received the fiber-reinforcing technique, whereas Groups A2, B2 and C2 received the direct restorative technique; the remainings were in Group D (blank control group), which did not receive treatment for the fracture resistance test. The fracture resistance test was divided into six experimental groups and one blank control group (n = 6). Primary molar teeth in each experimental group were prepared with Class II cavities and filled. The fracture load of all samples was detected, and the fracture mode was analyzed after thermal cycling. The microleakage test was divided into six experimental groups, with five in each group. Class I cavities with a diameter of 3 mm and depth of 2.5 mm were prepared within the mesial and distal marginal ridges on the occlusal surface and filled for primary molars in each group. Marginal microleakage was assessed after thermal cycling.@*Results@#The fracture resistance test results showed that the fracture resistance in groups that received the fiber-reinforcing technique was greater than that in groups that received the direct restorative technique: Group A1>Group A2, Group B1>Group B2, Group C1>Group C2 (P<0.05). The application of Ribbond fibers increased fracture resistance to all tested restorative materials by 37.08% to 39.34%. The proportion of tooth frac-ture decreased significantly in groups A1, C1 compared with A2, C2, with a significant increase in the occurrence rate of “Repairable” (P<0.05). The fracture resistance in Group A1 was significantly greater than that in Group B1 and Group C1 (P<0.05). The marginal microleakage test results showed that the microleakage depth in groups that received the fiber-reinforcing technique was smaller than that in groups that received the direct restorative technique: Group A1<Group A2, Group B1<Group B2, Group C1<Group C2 (P<0.05). The microleakage depth in groups that received the fiber-reinforcing technique decreased by 53.90% to 66.96% compared to that in groups that received the direct restorative technique. The microleakage depth in Group B1 was significantly less than that in Group A1 and Group C1.@*Conclusion@#The application of Ribbond fibers combined with various restorative materials could enhance fracture resistance and diminish the microleakage depth to improve marginal adaptation.
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Abstract This study aimed to evaluate the effect of antioxidant solutions on fracture strength and bonding performance in non-vital and bleached (38% hydrogen peroxide) teeth. One hundred and eighty dentin specimens were obtained, 60 for each test: fracture strength, hybrid layer thickness, and bond strength. The groups (n=10) were randomly composed according to post-bleaching protocol: REST - restoration, without bleaching; BL - bleaching + restoration; SA - bleaching, 10% sodium ascorbate solution, and restoration; AT - bleaching, 10% α-tocopherol solution, and restoration; CRAN - bleaching, 5% cranberry solution, and restoration; CAP - bleaching, 0.0025% capsaicin solution, and restoration. Data were analyzed with ANOVA, Kruskal-Wallis, Dunn, and Qui-Square tests (α=0.05). The highest fracture strength values were observed in REST (1508.96 ±148.15 N), without significant difference for the bleached groups (p>0.05), regardless of the antioxidant use. The hybrid layer thickness in the group that was not subjected to bleaching (REST) was significantly higher than in any other group. The bond strength in the bleached and antioxidants-treated groups (SA, AT, CRAN, CAP) has no differences with the bleached group without antioxidants (BL). Adhesive failures were predominant in the groups that did not receive the antioxidant application. In conclusion, the evaluated antioxidants did not show an effect on the fracture strength, hybrid layer thickness, or bond strength of dentin bleached after endodontic treatment. The application of 10% sodium ascorbate, 10% alpha-tocopherol, 5% cranberry, or 0.0025% capsaicin solutions is not an effective step and should not be considered for the restorative protocols after non-vital bleaching.
Resumo Este estudo teve como objetivo avaliar o efeito de soluções antioxidantes na resistência à fratura e resistência de união em dentes tratados endodonticamente e clareados (38% de peróxido de hidrogênio). Cento e oitenta espécimes de dentina foram obtidos, 60 para cada teste: resistência à fratura, espessura da camada híbrida e resistência de união. Os grupos (n=10) foram compostos aleatoriamente de acordo com o protocolo pós-clareamento: REST - restauração, sem clareamento; BL - clareamento + restauração; SA - clareamento, solução de ascorbato de sódio a 10% e restauração; AT - clareamento, solução de α-tocoferol a 10% e restauração; CRAN - clareamento, solução de cranberry a 5% e restauração; CAP - clareamento, solução de capsaicina 0,0025% e restauração. Os dados foram analisados com os testes ANOVA, Kruskal-Wallis, Dunn e Qui-Quadrado (α=0,05). Os maiores valores de resistência à fratura foram observados em REST (1508,96 ±148,15 N), sem diferença significativa para os grupos clareados (p>0,05), independente do uso de antioxidantes. A espessura da camada híbrida no grupo que não foi submetido ao clareamento (REST) foi significativamente maior do que em qualquer outro grupo. A resistência de união nos grupos clareado e tratado com antioxidantes (SA, AT, CRAN, CAP) não apresentou diferenças com o grupo branqueado sem antioxidantes (BL). As falhas adesivas foram predominantes nos grupos que não receberam a aplicação do antioxidante. Em conclusão, os antioxidantes avaliados não mostraram efeito sobre a resistência à fratura, espessura da camada híbrida ou resistência de união à dentina clareada após tratamento endodôntico. A aplicação de soluções de ascorbato de sódio 10%, alfa-tocoferol 10%, cranberry 5% ou capsaicina 0,0025% não é uma etapa eficaz e não deve ser considerada para os protocolos restauradores após clareamento não vital.
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The aim of this in vitro study was to evaluate the biomechanical and chemical behavior of various bioactive materials in class II MOD restorations. Forty- eight standardized class II MOD cavities were prepared in sound extracted human molar teeth. The specimens were divided into four groups according to the restorative material: Group 1 (Filtek™ Z350 XT), Group 2 (Biodentine™ as a liner, and then restored with Filtek™ Z350 XT), Group 3 (Cention N™), and Group 4 (Activa™ Bioactive-Restorative). The samples were tested for fracture resistance by subjecting them to a compressive load in a Universal testing Machine. The failure modes of each specimen were evaluated. The alkalinizing potential and calcium ion release of the materials were measured. SEM-EDAX analyses were also performed for all materials. Data were analyzed using ANOVA and post hoc Tukey test (p<0.05). Group 1 showed the higher fracture resistance (p<0.05). Group 3 had greater fracture resistance values but no statistical difference from Group 4. Biodentine™ showed greater biomineralization potential. Class II MOD restorations of Group 1 displayed the higher fracture resistance; however, it was highly associated with catastrophic failure. Conversely, Biodentine™ presented a more significant bioactivity potential, and its use, as in Group 2, promoted the most favorable failure mode.
El objetivo de este estudio, in vitro, fue evaluar el desempeño biomecánico y químico de varios materiales bioactivos en restauraciones clase II MOD. Se prepararon cuarenta y ocho cavidades clase II MOD estandarizadas en dientes molares humanos extraídos. Las muestras se dividieron en cuatro grupos según el material de restauración: Grupo 1 (Filtek™ Z350 XT), Grupo 2 (Biodentine™ como base y luego restaurado con Filtek™ Z350 XT), Grupo 3 (Cention N™) y Grupo 4 (Activa™ Bioactivo-Reparador). La prueba de resistencia a la fractura fue realizada en una máquina de ensayo universal Instron. Se evaluaron los modos de falla de cada espécimen. Se midió el pH y la liberación de iones de calcio de los materiales. Se realizaron análisis SEM-EDAX. Los datos se analizaron mediante ANOVA y la prueba post hoc de Tukey (p<0,05). El grupo 1 mostró la mayor resistencia a la fractura (p<0,05). El Grupo 3 tuvo mayores valores de resistencia a la fractura que el Grupo 4, pero sin diferencia estadística. Biodentine™ mostró un mayor potencial de biomineralización. Las restauraciones Clase II MOD del Grupo 1 mostraron la mayor resistencia a la fractura; sin embargo, estuvo altamente asociado con fallas irreparables. Por el contrario, Biodentine™ presentó un potencial de bioactividad más significativo y su uso, como en el Grupo 2, promovió el modo de falla más favorable.
Assuntos
Materiais Biomédicos e Odontológicos/análise , Resinas Compostas/análise , Resistência à FlexãoRESUMO
Context: Preparation of the root canal system is recognized as being one of the most important stages in root canal treatment which removes organic debris and microorganisms from the root canal system by means of chemico- mechanical preparation and irrigation of the canals. The use of nickel-titanium instruments has drastically reduced the time and the difficulties that were encountered with traditional hand instruments made up of stainless steel. Utilizing properties of super-elasticity, shape memory and different tapers of these instruments reduces not only the possibility of canal transportation but also affects both the geometry and volume of root canals. This subjects the root dentin to stress and consequently dentinal defects which increases the risk of root fracture during or after root canal treatment. Clinicians now have the opportunity to choose from differently tapered instruments having unique characteristics in their geometry and metallurgy. These are progressively tapered instruments, fixed tapered instruments, and variable tapered instruments, which come with the benefit of conforming to the root canal anatomy as well as removing dentin as little as possible while cleaning and shaping. The aim of this study was to examine the influence of instrument taperAim: on the fracture resistance of endodontically treated roots under in vitro experimental conditions.Conclusion: Under the limitations of this study in in-vitro conditions there were no significant differences between the fracture loads between the different file systems used, however samples prepared with Hyflex EDM recorded the highest fracture resistance, followed by ProTaper NEXT, ProTaper Gold and NeoEndo Flex respectively.
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Introduction: The aim of this study was to compare the fracture resistance of simulated immature teeth using four different apical plug materials, i.e. Pro? Root MTA, Neo? MTA Plus, Biodentine, and Bioactive Glass. Materials and Methods: 80 extracted human maxillary anterior teeth were divided into 4 groups for this study. They were prepared using Peeso reamers to simulate immature teeth and to mimic Cvek’s stage 3 of root development. A 5 mm apical barrier was placed using different materials. The remaining canal was obturated using gutta?percha and AH plus sealer. The final samples were stored at 37°C and 100% humidity for 4 weeks. Fracture resistance of the teeth was measured in Newtons using a universal testing machine. The comparison of fracture resistance between the four groups was done using Kruskal Walis ANOVA followed by post hoc Mann Whitney U test for pairwise comparison. Results: Biodentine group showed the highest fracture resistance as compared to the other three groups and the difference was highly significant (P < 0.001). Conclusions: Biodentine can be advocated over MTA as an effective material for the management of teeth with wide open apex. Bioactive glass also has shown promising results in increasing the fracture resistance of simulated immature teeth.
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Context: Fracture of endodontically treated teeth is a grave sequela that a clinician should seriously ponder. Suitable selection of restorative materials is a requisite for long?term clinical success. Aims: To compare the fracture resistance of endodontically treated teeth restored with three different posts luted using two different cements under all ceramic crowns. Settings and Design: This in vitro study was conducted in the Department of Prosthodontics, Government Dental College, Kottayam, Kerala, India. Methods and Material: Thirty endodontically treated single?rooted mandibular premolars in which post spaces were prepared and divided into three different groups. Group 1 (n = 10): zirconia post group. Group 2 (n = 10): quartz fibre post group. Group 3 (n = 10): glass fibre post group. Each group is sub?divided into two based on the luting system: resin?modified glass ionomer cement (RMGIC) or dual?cure resin cement (DCRC). The fracture resistance testing was performed in a universal testing machine with a crosshead speed of 0.5 mm/min. Statistical Analysis Used: The mean fracture resistance were analysed using independent sample Student t?test and one?way ANOVA. Results: Within the zirconia post group, the mean fracture resistance was higher in DCRC sub?group compared to the RMGIC sub?group and the difference was statistically significant (p = 0.017). The difference in fracture resistance between three different post systems was not found to be statistically significant with respect to both the luting systems. Conclusions: It was observed that when zirconia post is used, the mean fracture resistance was higher in dual?cure resin group compared to the resin?modified GIC group.
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Resumo Este estudo teve como objetivo avaliar a resistência à fractura do silicato de lítio reforçado com zircônio todo o material cerâmico "Celtra Press" em comparação com um "IPS e-max Press" em condições orais simuladas. Quatorze coroas cerâmicas foram fabricadas em moldes epóxi que foram duplicados a partir de moldes principais de aço inoxidável e divididos em dois grupos iguais (n=7) de acordo com o material de construção; Grupo A: Coroas fabricadas com material IPS e-max Press e Grupo B: Coroas fabricadas com material Celtra Press. As coroas foram então cimentadas nos seus moldes correspondentes com um cimento de resina auto-adesivo e submetidas a ciclos térmicos e cargas cíclicas. Em seguida, foram carregadas para fraturar numa máquina universal de ensaios. Os resultados foram tabulados e analisados estatisticamente utilizando os testes Kolmogorov-Smirnov e Shapiro-Wilk. O teste t de Student usado para comparar os valores médios. O nível de significância foi fixado em P ≤ 0,05 e intervalo de confiança de 95%. A análise estatística foi realizada utilizando o software Graph Pad Instat (Graph Pad, Inc.) para Windows. Os valores médios ± SD da resistência à fractura foram registados para o grupo Disilicate de lítio (1706,01 ±154,32 N) enquanto que os valores médios ± SD registados com o grupo celtra foram (1550,67±196,71 N). As coroas cerâmicas de silicato de lítio reforçado com zircónio produziram valores de resistência à fractura comparáveis aos das coroas cerâmicas de dissilicato de lítio e ambos os materiais testados estão dentro dos valores clinicamente aceitáveis na área posterior.
Abstract The aim of this study was conducted to assess the fracture resistance of zirconia reinforced lithium silicate all ceramic material "Celtra Press" compared to lithium disilicate one "IPS e-max Press" under simulated oral conditions. Fourteen ceramic crowns were fabricated on epoxy dies which were duplicated from stainless steel master die and divided into two equal groups (n=7) according to the material of construction; Group A: Crowns fabricated with IPS e-max Press material and Group B: Crowns fabricated with Celtra Press material. The crowns were then cemented onto their corresponding dies with a self-adhesive resin cement and subjected to thermocycling and cyclic loading. Then they were loaded to fractur in a universal testing machine. The results were tabulated and statistically analyzed using Kolmogorov-Smirnov and Shapiro-Wilk tests. Student t-test used to compare mean values. The significance level was set at P ≤ 0.05 and 95% Confidence interval. Statistical analysis was performed using Graph Pad Instat (Graph Pad, Inc.) software for windows. The mean ± SD values of fracture resistance were recorded for lithium Disilicate group (1706.01 ±154.32 N) meanwhile the mean ± SD value recorded with celtra group were (1550.67±196.71 N). Zirconia reinforced lithium silicate ceramic crowns produced comparable fracture resistance values to lithium disilicate ceramic crowns and both tested materials are within the clinically acceptable values in the posterior area.
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O aprimoramento da tecnologia CAD/CAM permitiu a confecção de placas estabilizadoras digitais, no entanto, há lacunas acerca do comportamento desses dispositivos frente a variáveis mecânicas e biológicas ainda desconhecidas. Dessa forma, o objetivo desse trabalho foi verificar se as resinas utilizadas na tecnologia digital das placas fresadas e impressas são capazes de influenciar na resistência à fratura e na adesão de micro-organismos em detrimento das resinas empregadas na confecção das placas termopolimerizáveis convencionais e se as propriedades testadas se relacionam com a variação da espessura desses dispositivos. Para tanto, foi realizado um estudo in vitro que contou com as fases mecânica e microbiológica, sendo cada uma composta pelos grupos Convencional (GC) (n=30), Fresado (GF) (n=30) e Impresso (GI) (n=30), de acordo com o método de confecção, possuindo cada um três subgrupos (n=10) que variaram a espessura dos espécimes de 1 a 3 mm. Na fase mecânica, as amostras, com formato de barras de 65 mm, foram testadas quanto à resistência à fratura na máquina de ensaios universal, com célula de carga de 500 kgf e velocidade de 1 mm/min; na microbiológica, a forma foi de discos com 15 mm de diâmetro, submetidos à adesão de micro-organismos à superfície com a exposição a Streptococcus mutans e mantidos por 24h a 35 °C em estufa para sucessiva contagem de UFC, com controle positivo. Os testes foram feitos em triplicata e os dados foram armazenados no SPSS 22.0 e a análise estatística contou com a ANOVA e o pósteste de Tukey. Nos resultados da fase mecânica, o ANOVA identificou diferenças estatisticamente significativas entre os grupos (p≤0,005), mostrando que GC e GF apresentaram melhores resultados. O pós-teste de Tukey considerou diferença estatisticamente significativa entre GF e GI (p=0,031), elencando GF como superior. Para a fase microbiológica, não foram verificadas diferenças estatísticas entre os grupos (p>0,005) em nenhuma das análises. Observou-se que para a resistência a fraturas, as resinas do modo fresado descreveram resultados superiores e/ou próximos aos da técnica convencional; e que as resinas da técnica digital e convencional, quanto à adesão superficial de micro-organismos, não diferiram entre si (AU).
CAD/CAM technology allowed the stabilizing splints manufacture, however there are gaps about these devices' behavior in face of mechanical and biological variables that are still unknown. Thus, the objective of this project was to verify if the resins used in digital technology of milled and printed stabilizer splints can influence fracture resistance and microorganism adhesion, in detriment of the resin applied in manufacture of conventional thermopolymerizable splints and if the tested properties are related to thickness variation of these devices. The method included mechanical and microbiological steps, each one composed by Conventional (CG) (n=30), Milled (MG) (n=30) and Printed (PG) (n=30) groups, according to the method of preparation, each one having three subgroups (n=10) that varied the specimen thickness from 1 to 3 mm. In the mechanical step, the samples, in the form of 65 mm bars, were tested for fracture resistance in a universal testing machine, with load cell of 500 kgf and speed of 1 mm/min; in the microbiological step, the shape was in form of 15 mm diameter discs, subjected to microorganism adhesion to the surface with exposure to Streptococcus mutans and kept for 24 hours at 35 °C in oven for successive CFU counting, with positive control. The tests were performed in triplicate and data were stored in SPSS 22.0 and statistical analysis used ANOVA and Tukey's post hoc. In the results of mechanical step ANOVA had identified statistically significant differences between the groups (p≤0,005), showing CG and MG had presented better results. Tukey´s post hoc had considered statistically significant difference between MG and PG (p=0,031), listing MG as superior. For the microbiological step, they did not show statistical differences between the groups (p>0.005) in any analysis. It was observed milled resins described superior results and/or close to the conventional technique one, for fracture resistance; and resins of digital and conventional technique, regarding the microorganism adhesion to the surface, did not differ from each other (AU).
Assuntos
Desenho Assistido por Computador/instrumentação , Resistência à Flexão , Adesão Celular , Análise de Variância , Adesões Focais/microbiologiaRESUMO
O objetivo deste relato de caso foi descrever em detalhes a técnica de transfixação de pino de fibra de vidro no sentido horizontal e restauração de resina composta em um dente molar tratado endodonticamete. Paciente, sexo feminino, 51 anos de idade, buscou o Centro Universitário da Serra Gaúcha (FSG Caxias do Sul Rio Grande do Sul) com a necessidade de realizar tratamento endodôntico do elemento molar número 26. Após a avaliação inicial, foi realizada a endodontia. O elemento havia pouca sustentação das paredes vestibular e palatina, então foi proposto a colocação de pino intrarradicular seguido de coroa, entretanto, por questões financeiras a paciente não aceitou. Logo, foi proposto a técnica de transfixação horizontal de pino de fibra de vidro associado a uma restauração de resina composta de forma direta. O procedimento foi realizado em sessão única e foi utilizado um pino de fibra de vidro número 1 disposto transversalmente entre as paredes mesiopalatina e distovestibular. A restauração foi realizada com resina composta Filtek Z350, devolvendo estética e função ao elemento dentário. Pode-se concluir que a técnica de transfixação horizontal de pino de fibra de vidro associado à resina composta é uma alternativa restauradora que possibilita maior resistência aos dentes tratados endodonticamente, apresenta resultados funcionais e estéticos satisfatórios, além de possibilitar uma maior sobrevida aos mesmos(AU)
The purpose of this case report was to describe in detail the technique of horizontal transfixion of a fiberglass post into an endodontically treated tooth. Female patient, 51 years old, sought the University Center of Serra Gaúcha (FSG - Caxias do Sul Rio Grande do Sul) with the need to perform the endodontic treatment of molar element number 26. After the initial evaluation, endodontics was performed. The element had little support for the buccal and palatal walls, so an intraradicular postplacement followed by a crown was proposed, for financial reasons the patient did not accept it. Therefore, the technique of horizontal transfixion of a fiberglass pin was proposed, associated with a restoration of direct composite resin. The procedure was performed in a single session and a number 1 fiberglass post was fixed crosswise between the mesiopalatal and distobuccal walls. The restoration was carried out with composite resin Filtek Z350, restoring aesthetics and function. It can be concluded that the horizontal transfixion of a fiberglass post associated with composite resin technique is a restorative alternative that allows greater resistance to endodontically treated teeth, provides satisfactory esthetics and better survival rates(AU)
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Resinas Compostas , Dente não Vital , Pinos Dentários , Dente Molar , Materiais Restauradores do Canal Radicular , Tratamento do Canal Radicular , Restauração Dentária Permanente , Resistência à FlexãoRESUMO
Objetivo: realizar uma revisão de literatura narrativa sobre a importância e a influência do efeito férula na resistência à fratura de restaurações em dentes tratados endodonticamente com utilização ou não de retentores intrarradiculares. Metodologia: Foram utilizados os seguintes descritores indexados no DeCS (Descritores em Ciências da Saúde): "Férula", Prótese Dentária", "Falha da Restauração Dentária", "Técnica de Retentor Intrarradicular" e "Pinos de Retenção Dentária" para busca nas bases de dados PubMed, Embase, Lilacs, Web of Science, Scopus e Cochrane Library. Resultados: Os dados da maioria dos estudos in vitro ou in vivo incluídos nesta revisão sugerem o uso da férula para aumento da resistência à fratura e longevidade dos dentes tratados endodonticamente. Tem sido recomendada a confecção de uma férula com altura uniforme de 2 mm e espessura superior a 1,5 mm. Conclusão: O uso de retentores radiculares foi indicado pela maioria dos trabalhos, sendo geralmente recomendados os pinos de fibra de vidro ao invés de núcleos metálicos fundidos para minimizar os riscos de fratura radicular em razão do módulo de elasticidade semelhante à dentina, além de possibilidade de retratamentos em casos de falhas adesivas. Apesar disso, ainda são necessários estudos clínicos com acompanhamento a longo prazo para avaliar a longevidade das restaurações de dentes tratados endodonticamente utilizando pinos de fibra de vidro sem ou com a presença de férula em diferentes espessuras e alturas.
Objective: This study aimed to conduct a narrative literature review on the importance and influence of the ferrule effect on the fracture resistance of restorations in endodon-tically treated teeth with or without the use of intraradicular posts. Methodology: The following descriptors indexed in the DeCS (Health Sciences Descriptors) were used: "Ferrule", Dental Prosthesis", "Dental Restoration Failure", "Post and Core Technique", and "Dental Posts", to search on the databases of PubMed, Embase, Lilacs, Web of Science, Scopus, and Cochrane Library data. Results: Data from most of the in vitro or in vivo studies included in this review suggest the use of the ferrule to increase fracture resistance and longevity of endodontically treated teeth. It has been recommended to make a ferrule with a uniform height of 2 mm and a thickness greater than 1.5 mm. Conclusion: The use of intraradicular posts was indicated by most studies, and fiberglass posts are generally recommended instead of cast metal cores to minimize the risk of root fracture due to the modulus of elasticity similar to dentin, in addition to the possibility of retreatments in ad-hesive failure cases. Despite this, clinical studies with a long-term follow-up are essential to evaluating the longevity of restorations of endodontically treated teeth using fiberglass posts without or with the presence of ferrule in different thicknesses and heights.
Assuntos
Contenções Periodontais , Técnica para Retentor Intrarradicular , Técnica para Retentor Intrarradicular/tendências , Falha de Restauração DentáriaRESUMO
@#Conservative endodontic access cavity (CEC) is the first step of minimally invasive endodontics. After that operation, teeth retain the dental hard tissue, such as crest and peri-cervical dentin, to a large extent. It is of great significance to reduce the tissue excision and achieve a favorable prognosis. There are a variety of approaches and corresponding cavities in CEC. The methods to determine the medullary approach include X-ray localization, micro CT/cone beam CT localization and digital guide plate localization. Among them, X-ray film and micro CT/cone beam CT are simple and commonly used in the clinic. For more complex root canal systems, the use of a digital guide plate can establish a more accurate pulp opening pathway and reduce the unnecessary loss of tooth hard tissue. However, the positioning price of a digital guide plate is high, and it has not been widely used in the clinic. The hole types of CEC include minimally invasive medullary hole type, super conservative minimally invasive medullary hole type, "Truss" hole type and cutting end hole type. The stress analysis of CEC and traditional endodontic access (TEC) cavity are mainly based on the loading of teeth by a universal mechanical testing machine in vitro, finite element analysis and clinical observation. Most scholars’ studies have shown that minimally invasive endodontics can improve the fracture resistance of teeth, but the differential capacities of CEC and TEC remain controversial. How does on balance the purpose of pulp treatment and the maximum retention of tooth tissue? Further exploration is still needed.
RESUMO
OBJECTIVE@#To compare the effects of resin base and different retention depth on the fracture resistance of mandibular molars restored with nano-ceramic endocrowns.@*METHODS@#Forty mandibular molars selected and randomly divided into 5 groups: ① The control group which was consisted of intact teeth, ② the non-resin base group, ③ the 2 mm retention depth group, ④ the 3 mm retention depth group, ⑤ the 4 mm retention depth group, respectively. After tooth preparation, in vitro root canal therapy was conducted, which was followed by endocrown design, production and adhesive of groups ②-⑤. All the samples were under load (N) of the universal mechanical testing machine after embedding. The fracture pattern of each sample was observed under stereomicroscope. Then the microstructure of the fracture surface was observed by scanning electron microscopy.@*RESULTS@#The fracture loads of each group were respectively: the control group fracture load was (3 069.34±939.50) N; experimental groups: fracture load of (2 438.04±774.40) N for the group without resin base; fracture load of (3 537.18±763.65) N for the group with 2 mm retention depth. The fracture load of the retention depth 3 mm group was (2 331.55±766.39) N; the fracture load of the retention depth 4 mm group was (2 786.98±709.24) N. There was statistical significance in the effect of resin base and different retention depth on the fracture loads of molars restored with nano-ceramic endocrown (P < 0.05). Repairable fractures in each group were as follows: control group 2/8, non-resin base group 1/8, retention depth of 2 mm group 1/8, retention depth of 3 mm group 2/8, and retention depth of 4 mm group 0/8. The effects of the retention depth and the presence of resin base on the fracture resistance of the resin nano-ceramic endocrowns were statistically significant (P < 0.05). Scanning electron microscopy showed more arrest lines and small twist hackles on the fracture surface of the restorations with resin base (retention depths of 2 mm, 3 mm, and 4 mm), with cracks extending towards the root. In addition to the characteristics above, more transverse cracks parallel to the occlusal surface, pointing outwards from the center of the pulp cavity retention, were also observed on the fracture surface of the non-resin base restorations.@*CONCLUSION@#When molar teeth with nano-ceramic endocrowns are restored, resin base and the retention depth of 2 mm help the teeth to obtain optimal fracture strength.
Assuntos
Cerâmica , Resinas Compostas , Porcelana Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário , Teste de Materiais , Dente MolarRESUMO
Background: Fragment re-attachment has been considered as one of the treatment modalities for the management of fractured anterior teeth. Hydration of fractured fragments aids in inhibiting the loss of ions and maintains vitality and esthetics. Aim: The study aimed to evaluate the effect of preconditioning the fractured fragments with remineralizing agents on fracture resistance of re-attached teeth. Settings and Design: This was an in vitro study. Materials and Methods: Sixty freshly extracted noncarious human permanent maxillary central and lateral incisors were randomly allocated into three Groups of 20 each: Group 1: 2% sodium fluoride (2%NaF), Group 2: casein phosphopeptide–amorphous calcium phosphate (CPP-ACP), and Group 3: self-assembling peptide P11-4 (SAP). These were further divided into two subgroups of 10 teeth each, based on contact time with remineralizing agents, i.e., 30 min and 2 h. Fractured fragments were treated with remineralizing agents for a specified contact time and then re-attached with flowable composite resin. Force required to fracture the re-attached tooth was recorded in Newtons using universal testing machine. Statistical Analysis: Unpaired t-test, one-way analysis of variance test, and post hoc Tukey test were used for the statistical analysis. Results: A higher fracture resistance was noticed in fragments treated with 2% NaF (30 min- 215.6 N, 2 h- 188.5 N) compared to CPP-ACP (30 min- 141.3 N, 2 h- 111.1 N) and SAP (30 min- 134.8 N, 2 h- 149.5 N). At 30 min interval, it was found to be more in 2% NaF and CPP-ACP groups compared to 2 h. However, it increased with time in the SAP group. A statistically significant difference was found between the groups at both time intervals (P = 0.007 and 0.017). Conclusion: Preconditioning of fractured coronal fragments with 2% NaF showed higher fracture resistance compared to CPP-ACP and self-assembling peptide P11-4. Samples treated with SAP P11-4 exhibited good fracture resistance at 2 h contact time.
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ABSTRACT: This study aimed to evaluate the fracture resistance of teeth restored with conventional, bulk-fill, and fiber-reinforced composite materials regarding intact teeth. Standard cavities were prepared on 70 sound third molar teeth. The teeth were randomly divided into six groups: intact teeth, conventional Bis-GMA based composite, fiber-reinforced composite, Bis-GMA based bulk-fill composite, ormocer based bulk-fill composite, glass containing resin-based bulk-fill composite. The data was obtained by a Universal Testing Machine and analyzed statistically. Fracture resistance of the teeth restored with conventional composite was significantly lower than the other groups (p0.05). The obtained data showed that restoring teeth with bulk-fill and fiber-reinforced composites could be recommended in Class II cavities.
RESUMEN: El objetivo del presente estudio fue evaluar la resistencia a la fractura de los dientes restaurados con materiales compuestos convencionales, de relleno y reforzados con fibras, en relación con los dientes intactos. Se prepararon cavidades estándar en 70 dientes de terceros molares sanos. Los dientes se dividieron al azar en seis grupos: dientes intactos, compuesto convencional basado en Bis-GMA, compuesto reforzado con fibra, compuesto de relleno a base de Bis-GMA, compuesto de relleno a base de ormocer, compuesto de relleno a base de vidrio que contiene resina. Los resultados fueron obtenidos utilizando una máquina universal de pruebas y analizados estadísticamente. La resistencia a la fractura de los dientes restaurados con el composite convencional fue significativamente menor que la de los otros grupos (p0,05). Los datos obtenidos mostraron que la restauración de dientes con composites de relleno y reforzados con fibra podría ser recomendada en cavidades de Clase II.
Assuntos
Selantes de Fossas e Fissuras , Mobilidade Dentária , Resinas CompostasRESUMO
Abstract This study assessed the fracture resistance of simulated immature teeth reinforced with calcium aluminate cement (CAC) or mineral trioxide aggregate (MTA) containing calcium carbonate nanoparticles (nano-CaCO3). The microstructural arrangement of the cements and their chemical constitution were also evaluated. Forty-eight canines simulating immature teeth were distributed into 6 groups (n=8): Negative control - no apical plug or root canal filling; CAC - apical plug with CAC; CAC/nano-CaCO3 - apical plug with CAC+5% nano-CaCO3; MTA - apical plug with MTA; MTA/nano-CaCO3 - apical plug with MTA+5% nano-CaCO3; and Positive control - root canal filling with MTA. The fracture resistance was evaluated in a universal testing machine. Samples of the cements were analyzed under Scanning Electron Microscope (SEM) to determine their microstructural arrangement. Chemical analysis of the cements was performed by Energy Dispersive X-ray Spectroscopy (EDS). The fracture resistance of CAC/nano-CaCO3 was significantly higher than the negative control (p<0.05). There was no significant difference among the other groups (p>0.05). Both cements had a more regular microstructure with the addition of nano-CaCO3. MTA samples had more calcium available in soluble forms than CAC. The addition of nano-CaCO3 to CAC increased the fracture resistance of teeth in comparison with the non-reinforced teeth. The microstructure of both cements containing nano-CaCO3 was similar, with a more homogeneous distribution of lamellar- and prismatic-shaped crystals. MTA had more calcium available in soluble forms than CAC.
Resumo Este estudo avaliou a resistência à fratura de dentes imaturos simulados reforçados com cimento de aluminato de cálcio (CAC) ou trióxido agregado mineral (MTA) contendo nanopartículas de carbonato de cálcio (nano-CaCO3). O arranjo microestrutural dos cimentos e sua constituição química também foram avaliados. Quarenta e oito caninos simulando dentes imaturos foram distribuídos em 6 grupos (n=8): Controle negativo - sem plug apical ou obturação do canal radicular; CAC - plug apical com CAC; CAC/nano-CaCO3 - plug apical com CAC + 5% nano-CaCO3; MTA - plug apical com MTA; MTA/nano-CaCO3 - plug apical com MTA + 5% nano-CaCO3; e Controle positivo - obturação dos canais radiculares com MTA. A resistência à fratura foi avaliada em máquina universal de ensaios. Amostras dos cimentos foram analisadas em Microscópio Eletrônico de Varredura (MEV) para determinar seu arranjo microestrutural. A análise química dos cimentos foi realizada por Espectroscopia de Energia Dispersiva de Raio-X (EDS). A resistência à fratura de CAC/nano-CaCO3 foi significativamente maior do que o controle negativo (p<0,05). Não houve diferença significativa entre os outros grupos (p>0,05). Ambos os cimentos apresentaram microestrutura mais regular com a adição de nano-CaCO3. As amostras de MTA apresentaram mais cálcio disponível em formas solúveis do que CAC. A adição de nano-CaCO3 ao CAC aumentou a resistência à fratura dos dentes em comparação aos dentes não reforçados. A microestrutura de ambos os cimentos contendo nano-CaCO3 foi semelhante, com uma distribuição mais homogênea de cristais de formato lamelar e prismático. MTA apresentou mais cálcio disponível nas formas solúveis do que CAC.
Assuntos
Humanos , Materiais Restauradores do Canal Radicular , Fraturas dos Dentes , Óxidos , Obturação do Canal Radicular , Silicatos , Compostos de Cálcio , Compostos de Alumínio , Ápice Dentário , Cimentos Dentários , Combinação de MedicamentosRESUMO
Objectives: To compare the clinical performance of milled PEEK-based single crowns to zirconia veneered single crowns through evaluation of restoration fracture, margin adaptation, and patient satisfaction. Material and Method: Twenty-four full coverage crowns were fabricated for posterior teeth. The patients were divided into two groups according to crowns' material: Group 1(control group) patients received Zr veneered crowns and Group2 (intervention group) patients received Bio HPP crowns. The preparations were standardized with supra-gingival, chamfer finish line for all teeth. The try-in and provisionalization were performed using CAD/CAM (CAM5-S1) machine with software (Exocad). The restorations were veneered according to manufactures instructions. The restoration surfaces were treated according to the manufacture instructions for each material. Self-adhesive resin cement (by BISCO) was used for both groups for crowns cementation. Fracture, margin integrity and biocompatibility (shade and function) were also evaluated during each recall visit using questionnaire to determine patient satisfaction. These measurements were repeated after two, four, six, eight, ten and twelve months respectively. Results: Fisher's Exact test was used to compare between the two groups; There was no statistically significant difference between the two groups (P-value = 1.000, Effect size = 0.478) for each time period, respectively. Conclusions: Both Zr veneered and Bio HPP crowns revealed successful clinical performance from the clinical performance aspect and patient satisfaction. No significant difference was recorded between the two materials; regarding the clinical performance and patient satisfaction. Therefore, careful checking of the surface of the veneering material one-year post-cementation is recommended (AU)
Objetivo: Comparar o desempenho clínico de coroas unitárias fresadas à base de PEEK com coroas unitárias estratificadas de zircônia por meio da avaliação da fratura da restauração, adaptação marginal e satisfação do paciente. Material e Métodos: Vinte e quatro coroas totais posteriores foram confeccionadas. Os pacientes foram divididos em dois grupos de acordo com o material das coroas: os pacientes do Grupo 1 (grupo controle) receberam coroas estratificadas de Zr e os pacientes do Grupo 2 (grupo de intervenção) receberam coroas BioHPP. Os preparos foram padronizados com linha de término supragengival e chanfro para todos os dentes. O try-in e a provisionalização foram realizados em máquina CAD / CAM (CAM5-S1) com software (Exocad). As restaurações foram estratificadas de acordo com as instruções do fabricante. As superfícies da restauração foram tratadas de acordo com as instruções do fabricante de cada material. O cimento resinoso autoadesivo (BISCO) foi utilizado para a cimentação das coroas em ambos os grupos. Fratura, integridade marginal e biocompatibilidade (tonalidade e função) também foram avaliadas durante cada consulta de retorno usando um questionário para determinar a satisfação do paciente. Essas medições foram repetidas após dois, quatro, seis, oito, dez e doze meses, respectivamente. Resultados: o teste exato de Fisher foi usado para comparação entre os dois grupos; não houve diferença estatisticamente significativa entre os dois grupos (P-valor = 1,000, tamanho do efeito = 0,478) para cada período de tempo, respectivamente. Conclusão: As coroas estratificadas de Zr e BioHPP revelaram um desempenho clínico bem-sucedido do ponto de vista do desempenho clínico e da satisfação do paciente. Nenhuma diferença significativa foi registrada entre os dois materiais; quanto ao desempenho clínico e satisfação do paciente. Portanto, recomenda-se a verificação cuidadosa da superfície do material de estratificação após um ano de cimentação.(AU)
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Humanos , Adaptação Marginal Dentária , Coroas , Resistência à FlexãoRESUMO
O acesso à cavidade pulpar é a etapa do tratamento endodôntico que tem como objetivo expor a embocadura dos canais radiculares. Por muito tempo, o formato ideal da cavidade era aquele que proporcionasse a criação de uma trajetória reta ao canal, com a remoção completa do teto da câmara pulpar. Porém, nas últimas décadas, foi investigado um desgaste excessivo de dentina que possibilita a redução da resistência do dente. Então, propuseram novo formato de cavidade de acesso, que permite a preservação máxima possível das estruturas de suporte, objetivando aumentar a resistência de dentes tratados endodonticamente. Apesar das vantagens, supostamente atribuídas aos acessos minimamente invasivos, esse formato tem sido questionado por dificultar a visibilidade da entrada dos canais, localização, e possibilidade de deixar áreas intocadas nas paredes dos canais. Diante disso, este trabalho realizou um levantamento bibliográfico a fim de verificar se há consistência científica quanto à interferência do acesso coronário na resistência dentária. Concluiu-se que o acesso minimamente invasivo não apresentou diferença quanto ao aumento da resistência à fratura de dentes tratados endodonticamente quando comparado ao acesso tradicional, entretanto, o tema ainda é relevante e os benefícios dessa técnica devem ser investigados clinicamente a longo prazo.
Access to the pulp cavity is the stage of endodontic treatment that aims to expose the mouth of the root canals. For a long time, creating a straight path to the canal, with the complete removal of the pulp chamber roof, was the ideal cavity format. However, in recent decades, excessive dentin wear, which makes it possible to reduce tooth strength, has been investi-gated. So, a new access cavity format, which allows the maximum possible preservation of the support structures, was proposed to increase the resistance of endodontically treated teeth. Despite the advantages supposedly attributed to minimally invasive accesses, this format has been questioned for hindering the visibility of the entrance to the channels, the location, and the possibility of leaving untouched areas on the walls of the channels. Therefore, this work carried out a bibliographical survey to verify the scientific consistency regarding the interference of coronary access in dental resistance. The minimally inva-sive access showed no difference regarding increased fracture resistance of endodontically treated teeth compared to the traditional access. However, the topic is still relevant, and its benefits, in the long term, should be clinically investigated.
Assuntos
Tratamento do Canal Radicular/tendências , Tratamento do Canal Radicular , Cavidade Pulpar/cirurgia , Endodontia/métodosRESUMO
As cavidades de acesso dominaram a recente discussão sobre a Endodontia minimamente invasiva (EMI). No entanto, a rotulagem da EMI é mais ampla, envolvendo o uso de instrumentos com conicidades reduzidas ou geometrias inovadoras que permitam a remoção mínima de dentina. Além disso, aprimoramentos metodológicos têm sido sugeridos para mimetizar condições clínicas. Buscando responder algumas questões acerca da EMI, a presente tese é dividida em dois estudos. O estudo 1 avaliou a influência do acesso ultraconservador (UltraAC) na instrumentação, na qualidade da obturação e na capacidade máxima de carga para fratura em molares inferiores após o preparo do canal com o sistema XP-endo Shaper (XP) ou Reciproc (RC) em condições clínicas simuladas. Para isso, quarenta molares inferiores foram microtomografados e pareados em quatro grupos (n = 10), de acordo com o acesso e a instrumentação: TradAC/RC, TradAC/XP, UltraAC/RC e UltraAC/XP. Os dentes foram reescaneados e os parâmetros da instrumentação e obturação foram analisados. Os dentes foram restaurados e submetidos à ciclagem termomecânica e à capacidade máxima de carga para a fratura. O teste ANOVA foi usado para a análise estatística (P < 0,05). Os grupos TradAC apresentaram menor porcentagem (%) de área não preparada do que os grupos UltraAC (P < 0,05). O grupo UltraAC/XP apresentou a menor % de dentina removida (P < 0,05). A % de debris foi menor nos grupos UltraAC/XP e TradAC/XP do que no UltraAC/RC e TradAC/RC (P < 0,05). Os grupos UltraAC demonstraram maior % de espaços vazios e de material obturador na câmara pulpar (P < 0,05). Não houve diferença na capacidade máxima de carga para a fratura entre os grupos (P > 0,05). O estudo 2 avaliou o uso de instrumentos com conicidade reduzida - Bassi Logic ,03 (BL), com diferentes designs (XP) e como grupo de comparação o sistem Reciproc, na eficácia da instrumentação dos canais em condições clínicas simuladas. Vinte e quatro molares foram microtomografados, acessados de forma tradicional e divididos em três grupos (n = 8), de acordo com o preparo: BL, XP e RC. Nos grupos BL e RC, os canais mesiais foram instrumentados com 25/,03 ou R25 e o canal distal com 25/,03 e 40/,03 ou R25 e R40, respectivamente. No grupo XP, o mesmo instrumento foi utilizado em todos os canais (30/,04). Após o preparo, os dentes foram reescaneados e a % de área não preparada e de dentina removida foram avaliadas separadamente para os canais mesiais e distal. Os dados foram analisados com os testes ANOVA e de Tukey (P < 0,05). Verificou-se que o grupo BL apresentou maior % de área não preparada para ambos os canais em relação aos grupos XP e RC (P < 0,05). No entanto, não houve diferença na % de dentina removida entre os grupos (P > 0,05). Com base nos estudos, conclui-se que as estratégias minimamente invasivas adotadas no acesso e na instrumentação foram desvantajosas frente a tratamentos tradicionais, não justificando o seu uso(AU)
Access cavities have dominated the recent discussion on minimally invasive Endodontics (EMI). However, the issue of MIE is broader than access cavities, such as the use of instruments with reduced taper or innovative geometries that allow minimal dentin removal. Furthermore, methodological improvements have been suggested to mimic clinical conditions. Seeking to answer some questions about EMI, this thesis is divided into two studies. The first study evaluated the influence of ultraconservative access (UltraAC) on canal shaping, filling ability and maximum load capacity for fracture of mandibular molars after root canal preparation with XP-endo Shaper (XP) or Reciproc (RC), under simulated clinical conditions. Thus, forty mandibular molars were scanned and paired into four groups (n = 10), according to access and instrumentation protocol: TradAC/RC, TradAC/XP, UltraAC/RC and UltraAC/XP. Teeth were rescanned and the instrumentation and filling parameters were analyzed. The teeth were restored and submitted to thermomechanical cycling and maximum load capacity for the fracture. ANOVA test was used for statistical analysis (P < 0.05). The TradAC groups had a lower percentage (%) of unprepared area than the UltraAC groups (P < 0.05). The UltraAC/XP group had the lowest % of dentin removed (P < 0.05). The % of debris was lower in the UltraAC/XP and TradAC/XP groups than in the UltraAC/RC and TradAC/RC groups (P < 0.05). The highest % of voids and filling material in the pulp chamber was observed in the UltraAC groups (P < 0.05). There was no difference in the maximum load capacity for the fracture between the groups (P > 0.05). The second study evaluated the use of a reduced taper endodontic instrument system - Bassi Logic .03 taper (BL), expandable heat-treated system (XP) and, as comparison, the Reciproc system, on the ability to shape canals under simulated clinical conditions. For that, twenty-four mandibular molars were scanned and divided into three groups (n = 8), according to root canal instrumentation system: BL, XP and RC. In the BL and RC groups, the mesial canals were instrumented with 25/.03 or R25 and the distal canal with 25/.03 and 40/.03 or R25 and R40, respectively. In the XP group, the same instrument was used in all root canals (30/.04). After preparation, the teeth were rescanned and the % of unprepared area and dentin removed were evaluated separately for the mesial and distal canals. Data were analyzed using ANOVA and Tukey tests (P < 0.05). It was found that the BL group had a higher % of unprepared area for both root canals compared to the XP and RC groups (P < 0.05). However, there was no difference in the % of dentin removed between groups (P > 0.05). Based on the studies, it is concluded that there is no justification for the use of EMI since in general, UltraAC did not promote advantages over TradAC and the use of instruments with reduced taper resulted in a larger unprepared area, which could possibly influence the cleaning of the root canal system (AU)