Survival of severely compromised endodontically treated teeth restored with or without a fiber glass post

Abstract Objective The use of a fiber glass post (FGP) type and choice of FGP diameter to restore endodontically treated incisors without ferrule is controversial. This study evaluated survival rate and failure mode of severely compromised central incisors without ferrule rehabilitated using resin-based composite (RBC) with or without FGP with different diameters. Methodology A total of 60 decoronated bovine incisors without a ferrule were endodontically treated and prepared for 1.4, 1.6, and 1.8 mm diameter FGPs (Whitepost System DC 0.5, Fit 0.4, and DCE 0.5; FGM). Half of the teeth received FGPs cemented using dual-cure resin cement (Allcem Core; FGM), the other half were filled using only bulk-fill RBC (OPUS Bulk Fill; FGM). The crowns were directly restored with RBC. The roots were embedded in polystyrene resin and the periodontal ligament was simulated with polyether impression material. Fatigue testing was conducted under 5 Hz cyclic loading at 30 degrees to the incisal edge, beginning at 50 N (5,000 cycles) as a warmup. After, the load was increased 100 N every 15,000 cycles until fracture occurred. All specimens were subjected to transillumination, micro-CT analysis, and digital radiography before and after fatigue testing. Fracture mode was classified according to severity and repair potential. Data were analyzed with Kaplan-Meier survival test and post hoc log-rank test (α=0.05) for pairwise comparisons. Results Using FGP significantly increased the number of cycles to failure, irrespective of FGP diameters (p=0.001). The FGP diameters had no statistically significant effect on cycles to failure or failure mode. Conclusion Using FGP without ferrule improved survival rate of structurally severely compromised central incisors compared with rehabilitation without FGP. The diameter of the FGPs had no effect on the survival rate and failure mode.

Estudio comparativo entre coronas, endocoronas y endocoronas con ausencia de una pared axial ante fuerzas de tracción / Comparative study between crown, endocrown and endocrown without one axial wall after tensile strength

Introducción: Las alternativas de tratamiento de órganos dentales con gran destrucción en su estructura varían, no sólo por el material de restauración, sino también por el valor económico y estético. Dentro de las alternativas existe: corona convencional, endocorona cuyo objetivo principal es la elaboración de una restauradora que evita la colocación de postes intraconducto y endocorona con ausencia de una pared axial (EPA) que se realiza cuando una pared, mesial, distal, vestibular o palatina está ausente. Objetivo: Verificar si la endocorona EPA se comporta de igual manera que las coronas convencionales y endocoronas al medir su resistencia ante fuerzas de tracción. Material y métodos: Treinta premolares fueron tratados endodóncicamente, 10 fueron preparados para recibir una corona convencional (grupo A), 10 para endocorona (grupo B) y 10 para endocorona EPA (grupo C). Se realizaron fuerzas de tracción para obtener el valor máximo en el cual las coronas fallaron. Se realizó una prueba ANOVA para comparar los resultados. Resultados: Al someter a los tres tipos de coronas a fuerzas de tracción los resultados obtenidos fueron: 3.04 ± 0.55 MPa para la corona, 7.08 ± 1.6 MPa para la endocorona y 6.17 ± 1.12 MPa para la endocorona EPA. Conclusiones: No existió diferencia significativa entre la endocorona (7.08 MPa) y la EPA (6.17 MPa), convirtiéndose en una alternativa de tratamiento con buen pronóstico en la práctica diaria (AU)

Introduction: The alternatives of treatment of tooth with excessive wear vary not only by the restoration material but also by the economic and aesthetic value. Among the alternatives there is: conventional crown, endocrown whose main objective is the elaboration of a restorative that avoids the placement of intraconducting posts and endocrown without one axial wall (EPA) that is done when a wall; mesial, distal, vestibular or palatal is absent. Objective: To verify if the (EPA) behaves in the same way as the conventional crown and endocrown when measuring its resistance to tensile strength. Material and methods: 30 premolars were treated endodontically, ten were prepared to receive a conventional crown, 10 for endocrown and 10 for EPA. Tensile strength were performed to obtain the maximum value at which the crowns failed, an ANOVA test was performed to compare the results. Results: When the three types of crowns were subjected to tensile strength, the results obtained were; 3.04 ± 0.55 MPa for the crown, 7.08 ± 1.6 MPa for the endocrown and 6.17 ± 1.12 MPa for the EPA endocrown. Conclusions: There was no significant difference between the endocrown (7.08 MPa) and EPA endocrown (6.17 MPa) becoming an alternative treatment with good prognosis in daily practice (AU)

Fenestration and dehiscence frequency in maxillary teeth with apical periodontitis: a CBCT study / Frecuencia de dehiscencias y fenestraciones en dientes maxilares con periodontitis apical: un estudio con TCHC

ABSTRACT Introduction: to determine the frequency of fenestration and dehiscence bone defects present in maxillary teeth with apical periodontitis, mainly in teeth with endodontic treatment, as they are frequently cause of nonspecific symptoms after treatment. Methods: 1201 Maxillary Cone Beam Computed Tomography (CBCT) exams were analyzed and 803 teeth with apical periodontitis were selected. Results: of the teeth with apical periodontitis, 142 had a fenestration defect (18%) of which 105 teeth (74%) were endodontically treated. The highest frequency was observed in premolars, with no statistical differences between groups. Dehiscence defect was found in 139 teeth (17%) out of which 90 (65%) were endodontically treated. The highest frequency was observed in molars, with statistical differences in relation to other tooth types (p< 0.001). Conclusion: an important number of teeth with apical periodontitis present dehiscence or fenestration bone defects, especially in teeth with root canal treatment.

Resumen Introducción: determinar la frecuencia de fenestraciones y dehiscencias presentes en dientes maxilares con periodontitis apical, principalmente en dientes con tratamiento de endodoncia, pues frecuentemente son causa de síntomas inespecíficos después del tratamiento. Métodos: se examinaron y analizaron 1201 tomografías computarizadas de haz cónico (TCHC), y se seleccionaron 803 dientes con periodontitis apical. Resultados: de los dientes con periodontitis apical, 142 presentaban fenestración (18%), de los cuales, 105 dientes (74%) estaban tratados endodónticamente. La mayor frecuencia fue observada en premolares, sin diferencias estadísticas entre los grupos. La dehiscencia fue encontrada en 139 dientes (17%), de los cuales 90 (65%) estaban tratados endodónticamente. La mayor frecuencia fue encontrada en molares con diferencia estadísticas en relación con los otros tipos de dientes (p<0,001). Conclusión: un importante número de dientes con periodontitis apical presentan fenestraciones y dehiscencias, especialmente en dientes con tratamiento de canales radiculares.

Endocrown: una alternativa rehabilitadora a las restauraciones rígidas totales clásicas / Endocrown: a rehabilitative alternative to

La restauración ideal en los dientes tratados endodónticamente (DTE) ha sido un tema controversial y ampliamente discutido en la literatura odontológica. El alto índice de fracasos en los dientes endodónticos se asocia principalmente a la falta de un adecuado sellado coronario, motivo por el cual la restauración post endodóntica cumple un papel fundamental. Los propios tejidos del DTE constituyen el refuerzo más importante de la pieza dentaria. La odontología considerada hoy en día como ideal es la mínimamente invasiva. A su vez la restauración de elección deberá ser aquella que respete mayor cantidad de tejido remanente a la hora de seleccionar la restauración coronaria. Se deberá considerar la cantidad y la calidad del remanente dentario sano, como los requisitos funcionales de cada pieza en particular. Si bien existen diversos tipos de restauraciones que podrían rehabilitar un DTE, en este trabajo sólo nos referiremos a las de inserción rígida, específicamente a las endo-onlays, también denominadas endocrowns (AU)

One year clinical evaluation of e-max press crowns retained with fiber reinforced composite post versus e-max press endocrowns in anterior endodontically treated teeth (a randomized clinical trial) / Avaliação clínica de um ano de coroas e-max retidas com resina composta reforçada por fibra versus endocrowns de e-max em dentes anteriores tratados endodonticamente: um ensaio clínico randomizado

Objective: The purpose of this study was to assess patient satisfaction, gross fracture and marginal adaptation of e.max press endocrowns versus e.max press crowns retained with Fiber reinforced composite post (FRCP) and core in upper anterior teeth. Material and methods: The present study included 24 patients seeking root canal treatment in anterior upper arch. The patients received root canal treatment (RCT) then they were randomly assigned into two groups (n=12). The first group received preparation for the IPS e.max crowns retained with FRCP and core and the second group received preparation for the IPS e.max endocrowns. Press technique was used for the fabrication of both restorations using IPS e.max press ingots. Marginal integrity and gross fracture were evaluated using USPHS criteria and a questionnaire was conducted to evaluate patient satisfaction. Data were analyzed using IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp. Results: There was no statistical significant difference regarding gross fracture of both groups after 12 months (p-value = 0.093, Effect size = 0.447), meanwhile; group 1 was statistically significantly higher than group 2 regarding marginal integrity (p-value = 0.037, Effect size = 0.513). Regarding patient satisfaction FRCP and core group showed statistical significant higher satisfaction than endocrown group (p-value = 0.047, Effect size = 0.447). Conclusion: E.max press endocrowns revealed successful performance similar to e.max press crowns retained with FRCP in terms of gross fracture, however better marginal adaptation and patient satisfaction was obtained with e.max press crowns retained with FRC post and core group. (AU)

Objetivo: O objetivo deste estudo foi avaliar a satisfação do paciente, grau de fratura grosseira e adaptação marginal de endocrowns e.max versus coroas de e.max retidas com pino de compósito reforçado com fibra (FRCP) e núcleo nos dentes anteriores superiores. Material e métodos: O presente estudo incluiu 24 pacientes que buscavam tratamento endodôntico na arcada superior anterior. Os pacientes receberam tratamento de canal radicular (RCT) e foram divididos aleatoriamente em dois grupos (n = 12). O primeiro grupo recebeu preparação para as coroas IPS e.max retidas com FRCP e núcleo e o segundo grupo recebeu preparos para as endocrowns IPS e.max. A técnica de prensagem foi usada para a fabricação de ambas as restaurações usando os lingotes de prensagem IPS e.max. A integridade marginal e a fratura macroscópica foram avaliadas usando os critérios da USPHS e um questionário foi realizado para avaliar a satisfação do paciente. Os dados foram analisados usando IBM SPSS Statistics for Windows, versão 23.0. Armonk, NY: IBM Corp. Resultados: Não houve diferença estatisticamente significativa em relação à fratura bruta de ambos os grupos após 12 meses (p-valor = 0,093, tamanho do efeito = 0,447), entretanto; o grupo 1 foi estatisticamente significativamente maior do que o grupo 2 em relação à integridade marginal (p-valor = 0,037, tamanho do efeito = 0,513). Em relação à satisfação do paciente, o FRCP e o grupo principal mostraram maior satisfação estatisticamente significativa do que o grupo endocrown (p-valor = 0,047, tamanho do efeito = 0,447). Conclusão: as endocrowns E.max press revelaram um desempenho bem-sucedido semelhante às coroas e.max press retidas com FRCP em termos de fratura bruta, no entanto, melhor adaptação marginal e satisfação do paciente foram obtidas com as coroas e.max press retidas com pilar FRC e núcleo de preenchimento (AU)

Influence of glass fiber posts and class III direct restorations on the resistance of anterior teeth / Influência dos pinos de fibra de vidro e restaurações diretas classe III na resistência dos dentes anteriores

This study objectives to evaluate the fracture strength of upper central incisors (UCI) restored with composite resin (CR) in Class III cavities and endodontically treated teeth with or without glass fiber post (GFP), analyzing their failure mode. Sixty human UCI were randomly divided into four experimental groups: endodontically treated teeth without GFP (G1), endodontically treated teeth with GFP (G2), teeth with mesial/distal Class III cavities restored with CR without GFP (G3), and teeth with mesial/distal Class III cavities restored with CR with GFP (G4). The samples were submitted to the fracture strength test in a universal testing machine with a compression shear load applied at speed of 1.0 mm/min until fracture occurred. The data were submitted to one-way ANOVA (α=0.05) and the samples were analyzed for failure mode. The analysis did not show a significant statistical difference in fracture strength between the groups (p>0.05). The results showed that only endodontically treated teeth (G1) (753.4N) presented behavior similar to teeth with GFP (G2) (702.1N). The same occurred when comparing teeth with Class III cavities without GFP (G3) (670.2 N) and with GFP (G4) (746.1N). It can be concluded that glass fiber posts do not change the fracture strength of incisors with endodontic treatment and Class III cavities.

Este estudo objetiva avaliar a resistência à fratura de incisivos centrais superiores (ICS) restaurados com resina composta (RC) em cavidades Classe III e dentes tratados endodonticamente com ou sem pino de fibra de vidro (PFV), analisando seu padrão de fratura. Sessenta ICS humanos foram divididos aleatoriamente em quatro grupos experimentais: dentes tratados endodonticamente sem PFV (G1), dentes tratados endodonticamente com PFV (G2), dentes com cavidades mesiais/distais Classe III restauradas com RC sem PFV (G3), e dentes com cavidades mesiais/distais Classe III restauradas com RC com PFV (G4). As amostras foram submetidas ao teste de resistência à fratura em uma máquina universal de ensaios com uma carga de cisalhamento de compressão aplicada na velocidade de 1,0 mm / min até a ocorrência da fratura. Os dados foram submetidos à ANOVA unidirecional (α=0,05) e as amostras foram analisadas quanto ao modo de falha. A análise não mostrou diferença estatisticamente significativa na resistência à fratura entre os grupos (p>0,05). Os resultados mostraram que os dentes apenas tratados endodonticamente (G1) (753,4N) apresentaram comportamento semelhante aos dentes com PFV (G2) (702,1N). O mesmo ocorreu ao comparar dentes com cavidades Classe III sem PFV (G3) (670.2 N) e com PFV (G4) (746.1N). Pode-se concluir que pinos de fibra de vidro não alteram a resistência à fratura de incisivos com tratamento endodôntico e cavidades Classe III.

Direct resin composite restoration of endodontically-treated permanent molars in adolescents: bite force and patient-specific finite element analysis

Abstract Objective To evaluate the influence of three levels of dental structure loss on stress distribution and bite load in root canal-treated young molar teeth that were filled with bulk-fill resin composite, using finite element analysis (FEA) to predict clinical failure. Methodology Three first mandibular molars with extensive caries lesions were selected in teenager patients. The habitual occlusion bite force was measured using gnathodynamometer before and after endodontic/restoration procedures. The recorded bite forces were used as input for patient-specific FEA models, generated from cone-beam computed tomographic (CT) scans of the teeth before and after treatment. Loads were simulated using the contact loading of the antagonist molars selected based on the CT scans and clinical evaluation. Pre and post treatment bite forces (N) in the 3 patients were 30.1/136.6, 34.3/133.4, and 47.9/124.1. Results Bite force increased 260% (from 36.7±11.6 to 131.9±17.8 N) after endodontic and direct restoration. Before endodontic intervention, the stress concentration was located in coronal tooth structure; after rehabilitation, the stresses were located in root dentin, regardless of the level of tooth structure loss. The bite force used on molar teeth after pulp removal during endodontic treatment resulted in high stress concentrations in weakened tooth areas and at the furcation. Conclusion Extensive caries negatively affected the bite force. After pulp removal and endodontic treatment, stress and strain concentrations were higher in the weakened dental structure. Root canal treatment associated with direct resin composite restorative procedure could restore the stress-strain conditions in permanent young molar teeth.

Resistencia a la Fractura de Dientes Tratados Endodónticamente Obturados con Selladores Biocerámicos Versus Selladores Resinosos. Revisión Sistemática / Fracture Resistance of Endodontically Treated Teeth Obturated with Bioceramic Sealers and Epoxy Resin-Based Sealers. A Systematic Review

RESUMEN: El objetivo de este estudio fue determinar mediante la revisión de la literatura científica disponible cuál es el tipo de cemento sellador que proporciona mayor resistencia a la fractura en dientes tratados endodónticamente, los cementos a base de biocerámicos o los en base a resina epóxica. Se realizó una revisión sistemática de acuerdo a las bases de los estamentos de PRISMA, en las bases de datos Medline, SciELO, Trip Database, LILACS, Web of Science, Cochrane. Se realizó la búsqueda a 10 años y se incluyeron sólo estudios in vitro. Se encontraron 202 artículos, luego se eliminaron los artículos duplicados y se excluyeron los estudios no atingentes por título y resúmenes, quedando ocho artículos que se revisaron a texto completo. En esta etapa se excluyeron dos estudios. Un total seis estudios fueron incluidos en esta revisión. De estos, ninguno encontró diferencia significativas entre cementos selladores a base de biocerámicos y a base de resina epóxica, en cuanto a resistencia a la fractura de los dientes tratados endodónticamente. Sin embargo, en 4 estudios los valores más altos encontrados de resistencia a la fractura estuvieron dados por los selladores en base a resina epóxica. Los artículos seleccionados, teniendo en consideración las limitaciones propias de los estudios in vitro, concluyen que en cuanto a resistencia a la fractura no hay diferencias significativas entre el uso de cementos selladores a base de biocerámicos y cementos selladores a base de resina epóxica en la obturación radicular de dientes tratados endodónticamente.

ABSTRACT: The objective of this study was to determine through the review of scientific literature, the type of sealer that provides the greatest resistance to fracture in endodontically treated teeth. Bioceramic sealer or epoxy resin based sealers were considered for this analysis. A systematic review was performed according to PRISMA, in the databases Medline, SciELO, Trip Database, LILACS, Web of Science, Cochrane. The search was carried out over the last 10 years, and only in vitro studies were included; 202 articles were found and subsequently, duplicate articles were eliminated, non-inferential studies by title and abstracts were excluded, leaving eight articles that were revised to full text. In this stage, two studies were excluded. In total, six studies were included in this review. Of these, none found significant difference between sealer cements based on bioceramics and based on epoxy resin, in terms of resistance to fracture of endodontically treated teeth. However, in 4 studies the highest found values of fracture resistance were given by sealers based on epoxy resin. Taking into account the limitations inherent to in vitro studies, this review concludes that in terms of fracture resistance, there are no significant differences between the use of sealer based on bioceramics and the based on epoxy resin in the root canal obturation.

Volume and/or time of naocl influences the fracture strength of endodontically treated bovine teeth

Abstract The aim of this study was to evaluate whether amplifying the volume and/or time of contact of NaOCl affects the fracture strength of endodontically treated bovine teeth. Four bovine incisors from 10 animals were allocated into 4 groups using a split-mouth design. Root canals were instrumented using a sequence of 4 manual stainless steel files and irrigated with a 5.25% alkalized NaOCl solution. The total volume and time of irrigation, per sample, varied among the groups as following: standard volume and time of contact - 15 mL/11.5 min; volume raise - 30 mL/11.5 min; time of contact raise - 15 mL/19 min; and volume and time of contact raise - 30 mL/19 min. Samples were subjected to a fracture resistance assay. At p=0.05, two-way ANOVA statistically scrutinized the results. Effect size of NaOCl time of contact and volume were also calculated (η2). The variation in time (p=0.000), volume of irrigation (p=0.000) and the combination of both (p=0.038) negatively influenced the fracture resistance. Standard volume and time of irrigation showed the highest fracture strength while isolated increase in volume or time reduced in 25% and 37%, respectively, the fracture resistance; the simultaneous increase in volume and time of irrigation promoted a reduction of 47%. Effect size of NaOCl time of contact was superior (0.746) than the volume (0.564). Raising the volume and/or time of a 5.25% alkalized NaOCl solution reduces the fracture resistance of endodontically treated bovine teeth.

Resumo O objetivo desse estudo foi o de avaliar se o aumento de volume e/ou tempo de contato do NaOCl afeta a resistência à fratura de dentes bovinos tratados endodonticamente. Quatro incisivos bovinos de 10 animais foram alocados em 4 grupos usando um desenho experimental de boca dividida. Os canais radiculares foram instrumentados usando uma sequência de 4 limas manuais de aço inoxidável e irrigados com uma solução de NaOCl alcalinizada a 5,25%. O volume total e o tempo de irrigação, por amostra, variaram entre os grupos da seguinte forma: volume e tempo de contato padrão (grupo controle) - 15 mL/11,5 min; aumento de volume - 30 mL/11,5 min; aumento no tempo de contato - 15 mL/19 min; e aumento no volume e no tempo de contato - 30 mL/19 min. As amostras foram submetidas a um ensaio de resistência à fratura. Com p=0.05, o teste two-way ANOVA analisou estatisticamente os resultados. O tamanho do efeito do tempo de contato e volume de NaOCl também foi calculado (h2). A variação no tempo (p=0,000), no volume de irrigação (p=0,000) e a interação entre ambos (p=0.038) influenciaram negativamente a resistência à fratura. O volume e o tempo padrão de irrigação apresentaram a maior resistência à fratura, enquanto o aumento isolado no volume ou no tempo de contato reduziram 25% e 37%, respectivamente, a resistência à fratura; o aumento simultâneo do volume e tempo de irrigação promoveu uma redução de 47%. O tamanho do efeito do tempo de contato com o NaOCl foi superior (0,746) ao volume (0,564). Aumentando o volume e/ou o tempo de uma solução de NaOCl alcalinizada a 5,25% reduz a resistência à fratura de dentes bovinos tratados endodonticamente.

Assessment of a conservative approach for restoration of extensively destroyed posterior teeth

Abstract Extensive restorations in posterior teeth always bring doubts to the clinicians regarding the best protocol, mainly when structures of reinforcement were lost. Objective This study aimed to evaluate the effect of beveling on the fracture resistance and pattern of class II (MOD) restored teeth. Methodology Ninety human premolars were randomly assigned into 9 groups: CTR (control/sound); NC (cavity preparation, non-restored); RU (restored, unbeveled); RTB (restored, entire angle beveling); RPB (restored, partial/occlusal beveling); EC (endodontic access/EA, non-restored); EU (EA, unbeveled); ETB (EA, entire angle beveling); EPB (EA, partial/occlusal beveling). Teeth were restored with Esthet X resin composite and stored in distilled water for 24 h before the inclusion in PVC cylinders. The axial loading tests were performed with 500 kgF at 0.5 mm/min crosshead speed until fracture of the specimens. Fracture resistance and pattern were accessed and data were analyzed using one-way ANOVA and Tukey's HSD test (α=0.05). Results Mean (±SD) failure loads ranged from 136.56 (11.62) to 174.04 (43.5) kgF in the groups tested without endodontic access. For endodontically accessed teeth, fracture resistance ranged from 95.54 (13.05) to 126.51 (19.88) kgF. Beveling of the cavosurface angle promoted the highest fracture resistance values (p<0.05) and prevented catastrophic fractures. Conclusions Cavosurface angle beveling is capable of improving fracture resistance and pattern for both endodonticaly accessed and non-accessed teeth.

Effects of intracanal medicaments and the remaining cavity wall on fracture strength of endodontically treated molars / Efeitos dos medicamentos intracanais e do muro de cavidade remanescente na força de fratura dos molares endodonticamente tratados

Objective: The aim of this study was to investigate the effects of the short-term intracanal application of two medicaments on the fracture strength of root-filled molar teeth with different levels of tooth structure loss. Material and Methods: Standard access cavities of totally 84 intact maxillary molar teeth were prepared in 72 teeth and were divided into 3 main groups. Standard access cavities were kept in the first group, while mesio-occlusal-distal cavities (MOD) were prepared in the second and third groups. One-half of the palatinal walls were removed in the third group. Twelve sound teeth were used in the fourth group as control. Each group was then assigned into two subgroups according to the medicament used (n=12): 2% chlorhexidine gel and calcium hydroxide. Samples were stored at 37°C and 100% humidity for 1 week. Then the teeth were inserted into a universal testing machine and vertically loaded (5 mm/min) from the occlusal surface. The data was recorded in Newtons and statistically evaluated using a Univariate ANOVA and a Tukey as post hoc test. Results: A significant difference was found among the test groups (p <0.01). No significant difference was found according to the medicament used (p>0.05), however the number of remaining walls significantly affected the fracture strength (p <0.01). The first group with access cavity showed mostly repairable fractures (60%­80%) whereas the others showed mostly nonrepairable fracture patterns s (60%­90%). Conclusion: In conclusion, the fracture strength of endodontically treated teeth is related to the structure loss rather than the intracanal medicament used. (AU)

Objetivo: O objetivo deste estudo foi investigar os efeitos da aplicação intracanal de curto prazo de dois medicamentos sobre a resistência à fratura de dentes molares preenchidos com raízes com diferentes níveis de perda de estrutura dentária. Material e Métodos: cavidades de acesso padrão de totalmente 84 dentes molar maxilares intactos foram preparadas em 72, dentes e foram divididas em 3 grupos principais. As cavidades de acesso padrão foram mantidas no primeiro grupo, enquanto as cavidades mesooclusais-distal (MOD) foram preparadas no segundo e terceiro grupos. A metade das paredes palatinas foi removida no terceiro grupo. Doze dentes de som foram utilizados no quarto grupo como controle. Cada grupo foi então atribuído em dois subgrupos de acordo com o medicamento utilizado (n = 12): 2% de gel de clorhexidina e hidróxido de cálcio. As amostras foram armazenadas a 37 ° C e 100% de umidade por 1 semana. Em seguida, os dentes foram inseridos em uma máquina de teste universal e carregados verticalmente (5 mm / min) da superfície oclusal. Os dados foram registrados em Newtons e avaliados estatisticamente usando uma ANOVA Univariada e um Tukey como teste post hoc. Resultados: uma diferença significativa foi encontrada entre os grupos de teste (p <0,01), no entanto, o número de paredes restantes afetou significativamente a resistência à fratura (p <0,01). O primeiro grupo com cavidade de acesso apresentou fracturas principalmente reparáveis (60% -80%), enquanto as demais apresentaram padrões de fratura não reparáveis (60% -90%). Conclusão: Em conclusão, a resistência à fratura dos dentes tratados endodonticamente está relacionada à perda da estrutura em vez do medicamento intracanal utilizado.(AU)

Evaluation of Stress Distribution in Endodontically Weakened Teeth Restored with Different Crown Materials: 3D-FEA Analysis

Abstract This study evaluated the stress distribution in endodontically treated teeth, weakened (W) or not weakened (NW), restored with different materials of prosthetic crown using 3D-FEA. Models of a maxillary canine were constructed based on micro-CT images and divided into the groups: G1 (control) - sound tooth; G2 to G7 - endodontically treated teeth restored with glass fiber post (GFP); which G2 to G4 simulated NW root and G5 to G7 simulated W root. For crown material the teeth were restored with: G2 and G5: metallic coping and ceramic veneering, G3 and G6: zirconia coping and ceramic veneering, G4 and G7: alumina coping and ceramic veneering. Load of 180 N was applied at the incisal third of lingual surface at 45º. Models were supported by the periodontal ligament (x=y=z=0). The von Mises stress (VMS) values were calculated. The W teeth presented higher VMS at coping when compared to NW teeth and group G1 showed lower VMS value. For crown material, for both W or NW teeth, increasing VMS was found at metallic, zirconia and alumina coping, respectively. Metallic coping showed a better performance despite its unfavorable esthetics, suggesting as an appropriate material for prosthetic restoration of endodontically treated teeth.

Resumo Este estudo avaliou a distribuição de tensão em dentes tratados endodonticamente, fragilizados (F) ou não fragilizados (NF), restaurados com diferentes materiais para a coroa protética utilizando 3D-FEA. Modelos de um canino maxilar foram construídos baseados em imagens de micro-CT e divididos em grupos: G1 (controle) - dente hígido; G2 a G7 - dentes tratados endodonticamente com pino de fibra de vidro (PFV), sendo que G2 a G4 simularam raízes NF e G5 a G7 simularam raízes F. Para o material das coroas os dentes foram restaurados com: G2 e G5: coping metálico e revestimento cerâmico, G3 e G6: coping de zirconia e revestimento cerâmico, G4 e G7: coping de alumina e revestimento cerâmico. Carregamento de 180 N foi aplicado na superfície lingual em seu terço incisal com 45 graus de inclinação. Os modelos foram suportados pelo ligamento periodontal (x=y=z=0). Os valores da tensão de von Mises (VMS) foram calculados. Os dentes F apresentaram maiores valores VMS para o coping quando comparados aos dentes NF, sendo que o G1 apresentou menores valores VMS. Para o material das coroas, ambos F ou NF aumentaram VMS no coping metálico, zirconia e alumina, respectivamente. Copings metálicos apresentaram melhor comportamento mecânico apesar de não favorecerem a estética, o que sugere ser um material apropriado para a restauração de dentes tratados endodonticamente.

Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts

Abstract Objective This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC), MultiCore Flow (MCF), and LuxaCore Z-Dual (LCZ)), and a nanohybrid composite, (Tetric N-Ceram (TNC)). Material and Methods Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post) cemented with resin cement (Panavia F2.0). Samples were randomly divided into four groups (n=10). Each group was built-up with one of the four core materials following its manufacturers’ instructions. The teeth were embedded in acrylic resin blocks. Nickel-Chromium crowns were fixed on the specimens with resin cement. The fracture resistance was determined using a universal testing machine with a crosshead speed of 1 mm/min at 1350 to the tooth axis until failure occurred. All core materials used in the study were subjected to test for the flexural modulus according to ISO 4049:2009. Results One-way ANOVA and Bonferroni multiple comparisons test indicated that the fracture resistance was higher in the groups with CPC and MCF, which presented no statistically significant difference (p>0.05), but was significantly higher than in those with LCZ and TNC (p<0.05). In terms of the flexural modulus, the ranking from the highest values of the materials was aligned with the same tendency of fracture loads. Conclusion Among the cores used in this study, the composite core with high filler content tended to enhance fracture thresholds of teeth restored with fiber posts more than others.

Efeito de diferentes sistemas de obturação na resistência à fratura de raízes tratadas endodonticamente / The Influence of different obturation systems on the fracture resistance of endodontically treated roots

Objective: This study aimed to compare the fracture resistance of endodontically treated roots filled by different obturation systems. Material and methods: Ninety-six maxillary central incisors were used and decoronated, retaining 12 mm of the roots. On the basis of obturation systems, the roots were randomly divided into 4 groups (n=24): Group1 (COGR): control group (unprepared, unfilled), Group 2 (AVGR): ActiV GP points/ActiV GP sealer, Group 3 (GPGR): Gutta percha points / AH plus sealer, and Group4 (GAGR): Gutta percha points/ActiV GP sealer. The last three groups were obturated with the single cone technique. The roots were then stored in 100% relative humidity at 37 °C for 2 weeks. A vertical compressive force was exerted in a universal testing machine until fracture occurred. Data were statistically analyzed using one-way ANOVA. Results: Mean (SD) failure loads for groups ranged from 920.51 ± 210.37 to 1113.44 ± 489.42 N. The fracture resistance between the different study groups indicated no statistical difference (p>0.05). Conclusions: ActiV GP system did not exert a significant effect on the fracture resistance of endodontically treated teeth.(AU)

Objective: Comparar a resistência à fratura de raízes tratadas endodonticamente obturadas através de diferentes sistemas. Materiais e Métodos: Noventa e seis incisivos centrais superiores foram utilizados, tiveram as coroas removidas, restando 12 mm de raíz. De acordo com o sistema de obturação, as raízes foram divididas em 4 grupos (n=24): Grupo1 (COGR): grupo controle (sem preparo, sem preenchimento), Grupo2 (AVGR): cones ActiV GP / cimento ActiV GP, Grupo3 (GPGR): cones de guta percha / cimento AH plus, e Grupo4 (GAGR): cones de guta percha / cimento ActiV GP. Os últimos três grupos foram obturados através da técnica de cone único. As raízes foram armazenadas em 100% de umidade relativa a 37 °C durante 2 semanas. Uma força compressiva vertical foi aplicada através de uma máquina de ensaio universal até ocorrer fratura. Os dados foram analisados estatisticamente através de ANOVA ­ 1 fator. Resultados: A carga média (SD) obtida no momento da falha variou entre 920.51 ± 210.37 até 1113.44 ± 489.42 N. A resistência à fratura entre os diferentes grupos estudados não indicaram diferença estatística. Conclusão: O sistema ActiV GP não exerceu um efeito significante na resistência à fratura em dentes tratados endodonticamente.(AU)

Fracture resistances of zirconia, cast Ni-Cr, and fiber-glass composite posts under all-ceramic crowns in endodontically treated premolars

PURPOSE: The aim of the present study was to evaluate the fracture resistances of zirconia, cast nickel-chromium alloy (Ni-Cr), and fiber-composite post systems under all-ceramic crowns in endodontically treated mandibular first premolars. MATERIALS AND METHODS: A total of 36 extracted human mandibular premolars were selected, subjected to standard endodontic treatment, and divided into three groups (n=12) as follows: cast Ni-Cr post-and-core, one-piece custom-milled zirconia post-and-core, and prefabricated fiber-glass post with composite resin core. Each specimen had an all-ceramic crown with zirconia coping and was then loaded to failure using a universal testing machine at a cross-head speed of 0.5 mm/min, at an angle of 45 degrees to the long axis of the roots. Fracture resistance and modes of failure were analyzed. The significance of the results was assessed using analysis of variance (ANOVA) and Tukey honest significance difference (HSD) tests (α=.05). RESULTS: Fiber-glass posts with composite cores showed the highest fracture resistance values (915.70±323 N), and the zirconia post system showed the lowest resistance (435.34±220 N). The corresponding mean value for the Ni-Cr casting post and cores was reported as 780.59±270 N. The differences among the groups were statistically significant (P<.05) for the zirconia group, as tested by ANOVA and Tukey HSD tests. CONCLUSION: The fracture resistance of zirconia post-and-core systems was found to be significantly lower than those of fiberglass and cast Ni-Cr post systems. Moreover, catastrophic and non-restorable fractures were more prevalent in teeth restored by zirconia posts.

Management of large class II lesions in molars: how to restore and when to perform surgical crown lengthening?

The restoration of endodontic tooth is always a challenge for the clinician, not only due to excessive loss of tooth structure but also invasion of the biological width due to large decayed lesions. In this paper, the 7 most common clinical scenarios in molars with class II lesions ever deeper were examined. This includes both the type of restoration (direct or indirect) and the management of the cavity margin, such as the need for deep margin elevation (DME) or crown lengthening. It is necessary to have the DME when the healthy tooth remnant is in the sulcus or at the epithelium level. For caries that reaches the connective tissue or the bone crest, crown lengthening is required. Endocrowns are a good treatment option in the endodontically treated tooth when the loss of structure is advanced.

Endocrown: estudio clínico retrospectivo de una serie de pacientes, en un período de 8 a 19 años / Endocrown: a retrospective patient series study, in a 8 to 19-year period

Objetivo: El objetivo de este trabajo es presentar el resultado clínico retrospectivo de 11 Endocrowns, realizados por el primer autor en su consultorio privado, en un período de 8 a 19 años. Materiales and Métodos: Se establecieron criterios de inclusión y exclusión para la muestra y las restauraciones. En ciento treinta pacientes seleccionados al azar, 11 Endocrowns habían sido realizados en 11 pacientes. Tres materiales restauradores y tres cementos de resina fueron utilizados. Se analizaron diferentes variables. El Indice Kappa de Cohen, referido al análisis de calidad de las restauraciones, tuvo una variación de 0.78 a 1. Para analizar las diferencias estadísticas significativas se utilizaron métodos estadísticos descriptivos. Resultados: Al momento del examen, 10 (90.9%) Endocrowns estaban en función Uno (9.1%) había fracasado. Conclusiones: Endocrown, es un procedimiento restaurador técnicamente sensible, conservador, estético, fácil, rápido, con muy aceptable funcionalidad y longevidad, para rehabilitar dientes posteriores endodónticamente tratados, principalmente molares.

Purpose. The aim of this paper is to present the retrospective clinical performance of 11 endocrowns, placed in a single private practice in an 8-to-19-year period. Materials and Methods. Inclusion and exclusion criteria for the sample and the restorations were established. One hundred and thirty patients were selected at random. Eleven endocrowns had been placed in 11 patients. Three restorative materials and three resin cements were used. Cohen’s Kappa coefficient, on the quality analysis of the restorations, ranged from 0.78 to 1. Due to the small sample, inferential statistical methods could not be used. Therefore, statistical descriptive methods were applied. Results. At the moment of the clinical examination, 10 (90.9%) endocrowns were in function and 1 failed (9.1%). Conclusions. Endocrown is a conservative and aesthetic technique-sensitive procedure used to restore posterior endodontically treated teeth, mainly molars, with a very good biomechanical and functional performance, and very acceptable longevity.

Conservative Management Of Endodontically Treated Mandibular Molar By Indirect Composite: A Novel Approach.

Introduction: The patient’s desire for esthetics, coupled with the decreasing use of amalgam, requires that clinicians be comfortable and proficient in the use and placement of tooth-colored restoratives.Case Report: A 30 yrs old male came with chief complaint of large metallic filling on lower left back region came to the department for esthetic restoration. Patient had dental history of endodontic treatment with 36,37,46,47 and periodontal surgery with 46,47. Patient was advised by endodontic department for proper restoration of endodontically treated teeth to avoid fracture of treated tooth.Discussion: Indirect composite restorations demonstrate enhanced physical properties and predictable clinical performance having less polymerization shrinkage than direct composites. There is more strength in highly filled indirect composite. One of the most important attributes of indirect composite is the ability to create ideal contours and contacts with adjacent and opposing teeth that might be difficult to achieve clinically with large, directly placed composite restorations. [Kaushik ANJIRM 2016; 7(5):98-100]

Resistencia a la fractura de postes de fibra de vidrio vs postes colados en dientes anteriores. Revisión sistemática / Fracture Resistance of fiberglass post vs cast post in anterior teeth. Systematic review

Los dientes anteriores con tratamiento endodóntico y con pérdida de estructura dental usualmente son restaurados con postes de fibra de vidrio o con postes colados, y son susceptibles a presentar fallas que pueden llegar a ocasionar la pérdida dental por no ser rehabilitables. Se propone aquí, identificar cuál entre los dos tipos de postes: prefabricados de fibra de vidrio o postes colados, es más resistente a la fractura debido a las fuerzas biomecánicas compresivas o tensionales que se suceden en los dientes anteriores rehabilitados con coronas respecto a la fractura del poste, de la raíz o el desalojo de este. Se realizó una revisión sistemática de la literatura, con información recolectada desde las bases de datos de los buscadores: PubMed, Scielo, Lilacs y Science Direct. Noventa y tres artículos sobre el tema fueron tamizados según los criterios de selección. Cuatro cumplieron con este procedimiento y se encontró que la resistencia a la fractura tiende a ser mayor en dientes restaurados con postes colados, pero cuando se presenta una fractura es desfavorable para el retratamiento restaurativo. En el caso de los postes de fibra de vidrio se presenta mejor resistencia a la fractura y presentan un patrón por lo general más favorable para un retratamiento en caso de éste fracaso.

Anterior teeth with endodontic treatment and loss of tooth structure are usually restored with glass fiber posts or cast cores, which are susceptible to present failures that may potentially cause tooth loss because they are not able to be restored again. It is proposed here to identify which of the two types of posts: prefabricated fiberglass or cast posts, is more resistant to fracture due to biomechanical forces of compression that occur in the anterior teeth restored with crowns respect to fracture post , root or eviction of this. A systematic review of the literature was conducted with information gathered from the databases of search engines: PubMed, Scielo, Lilacs and Science Direct. Ninety three articles on the topic were screened according to the selection criteria. Four cumplied with this procedure and found that fracture resistance tends to be grater in teeth restored with cast posts, but when a tracture accors is untaorubale for a restorative retreat. In the case of fiberglass posts and greater remaining height structure better fracture resistance is presented, and they present a pattern usually more favorable for retreatment in case of fracture.

Accuracy of color measurement of endondontically treated teeth after aging / Precisão da medição de cor de dentes tratados endodonticamente após envelhecimento

Objective: The aim of this study was to compare the accuracy of three different modes of a spectrophotometer (Vita Classical, 3D-Master and CIE L*a*b* system) in the evaluation of color alteration in endodontically treated teeth. Material and Methods: The root canal treatment of forty-five sound human canines was performed. Color measurements were performed before the endodontic treatment (baseline), and after 6 months of water storage. Shade matching was performed using a spectrophotometer (Vita Easyshade) in three different modes: Vita Classical, 3D-Master and CIE L*a*b* coordinates. The color change (ΔE value) for the three methods were assessed in each sample and analyzed by multiple linear regression analysis. L*, a* and b* values were analyzed by t-test. The significance level was set at 5%. Results: According to the digital evaluation, no statistically significant differences were found between the CIE L*a*b*,Vita Classical and 3D-Mastermodes. However, a significant difference was found (p < 0.001) for the ΔE values, with the CIE L*a*b* mode presenting greater accuracy to detect color alterations. Conclusion: CIE L *a*b* method properly correlates to Vita Classical and 3D-Master modes. However, Easyshade can easier detect color changes if used in the CIE L*a*b* mode, which leads to more accurate results.

Objetivo: O objetivo deste estudo foi comparar a precisão de três modos diferentes de um espectrofotômetro (Vita Classical, 3D-Master e sistema CIE L*a*b*) na avaliação da alteração de cor em dentes tratados endodonticamente. Materiais e Métodos: O tratamento endodôntico de quarenta e cinco caninos humanos foi realizado. Medições de cor foram realizadas, antes do tratamento endodôntico (imediatamente), e após 6 meses de armazenamento em água. Análise de cor foi realizado utilizando um espectrofotômetro (Vita Easyshade) em três diferentes modos: Vita Classical, 3D-Master e sistema CIE L*a*b*. A mudança de cor (valor ΔE) para os três métodos foram avaliadas em cada amostra e analisados através de análise de regressão linear múltipla. Valores de L*, a* e b* foram analisados através do teste-t. O nível de significância estabelecido foi de 5%. Resultados: De acordo com a avaliação digital, não foram encontradas diferenças significativas entre os métodos CIE L*a*b*,Vita Classical e 3D-Master. No entanto, uma diferença significativa foi encontrada (p < 0,001) para os valores de ΔE, com o modo CIE L*a*b* apresentando uma maior precisão para detectar alterações de cor. Conclusão: O método CIE L *a*b* correlaciona corretamente para os modos Vita Classical e 3D-Master. No entanto, o Easyshade pode detectar alterações de cor, mais facilmente quando utilizado no modo CIE L *a*b*, permitindo resultados mais precisos.