Influência do design de restaurações endocrown em CAD/CAM na carga máxima de carregamento em molares tratados endodonticamente

Objetivos: avaliar in vitro a influência de diferentes designs de preparos cavitários para restaurações endocrown, na resistência máxima ao carregamento de molares endodonticamente tratados. Materiais e métodos: Cinquenta terceiros molares hígidos e extraídos foram divididos aleatoriamente em 5 grupos (n= 10 por grupo), H= hígido, F1= 1 férula, F2 = 2 férulas VL(vestibular e lingual), FT= férula total e SF= platô reto. Os dentes foram submetidos à endodontia e, após, realizados os preparos cavitários. As coroas de endocrown, em Lava Ultimate, foram confeccionadas através do sistema CAD-CAM CEREC/INLAB e cimentadas com Single Bond Universal e Rely X Ultimate. O ensaio de resistência à fratura foi realizado em uma máquina de ensaios universal com velocidade de 1mm/min até o rompimento do corpo de prova. Após, foi avaliado o padrão de falha o qual levou em consideração apenas a presença ou não de fratura do assoalho pulpar. Resultados: (médias seguidas de mesma letra não apresentam diferença estatística para ANOVA e Tukey): H:3970N AB; F1:3170N AB; F2: 3786N AB; FT 2894N B; SF:4416N A. O padrão de falha predominante foi do tipo fratura da restauração em todos os grupos. Conclusões: o tipo de preparo cavitário para restaurações endocrown pode influenciar na resistência à fratura de molares tratados endodonticamente. O tipo de férula utilizada pode determinar maior resistência ao carregamento. O padrão de falha foi predominantemente recuperável.Objectives: To evaluate in vitro the influence of different cavity design preparations for endocrown restorations on the fracture resistance of endodontically treated molars. Materials and methods: Fifty extracted healthy third molars were divided randomly into 5 groups (n= 10 per group): H= healthy, F1= 1 ferrule, F2= 2 ferrules (buccal and palatal), FT= total ferrule and NF= flat plateau. The teeth were submitted to root canal treatment after which the cavity preparations were made. The crowns of endocrown, in Lava Ultimate, were manufactured with the CAD-CAM CEREC/INLAB system and cemented with Single Bond Universal and Rely X Ultimate. The resistance to fracture testing was made in a universal testing machine with a speed of 1mm/min. The pattern of failure was then evaluated, taking into consideration only the presence or absence of fracture in the pulp floor. Results: (Means followed by the same letter do not differ statistically for ANOVA and Tukey): H:3970N ab; F1:3170N ab; F2: 3786N ab; TF: 2894N b; NF:4416N a. The most prevalent pattern of failure was the type recoverable in all groups. Conclusions: The type of cavity preparation for endocrown restoration may influence the fracture resistance of endodontically treated molars. The type of ferrule may determine the greater resistance to loading. The pattern of failure was predominantly recoverable

Fracture Resistance and Microleakage of Endocrowns Utilizing Three CAD-CAM Blocks

This study assessed marginal leakage and fracture resistance of computer-aided design/computer-aided manufacturing (CAD/CAM) fabricated ceramic crowns with intracoronal extensions into the pulp chambers of endodontically treated teeth (endocrowns) using either feldspathic porcelain (CEREC Blocks [CB], Sirona Dental Systems GmbH, Bensheim, Germany), lithium disilicate (e.max [EX], Ivoclar Vivadent, Schaan, Liechtenstein), or resin nanoceramic (Lava Ultimate [LU], 3M ESPE, St Paul, MN, USA).). Thirty extracted human permanent maxillary molars were endodontically treated. Standardized preparations were done with 2-mm intracoronal extensions of the endocrowns into the pulp chamber. Teeth were divided into three groups (n=10); each group was restored with standardized CAD/CAM fabricated endocrowns using one of the three tested materials. After cementation with resin cement, specimens were stored in distilled water at 37°C for one week, subjected to thermocycling, and immersed in a 5% methylene-blue dye solution for 24 hours. A compressive load was applied at 35 degrees to long axis of the teeth using a universal testing machine until failure. Failure load was recorded, and specimens were examined under a stereomicroscope for modes of failure and microleakage. Results were analyzed using one-way analysis of variance and Bonferroni post hoc multiple comparison tests (α=0.05). LU showed significantly (p<0.05) higher fracture resistance and more favorable fracture mode (ie, fracture of the endocrown without fracture of tooth) as well as higher dye penetration than CB and EX. In conclusion, although using resin nanoceramic blocks for fabrication of endocrowns may result in better fracture resistance and a more favorable fracture mode than other investigated ceramic blocks, more microleakage may be expected with this material

Endocrown: uma alternativa restauradora para dentes tratados endodonticamente.

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências da Saúde. Odontologia.Com o advento da tecnologia adesiva, tornou-se possível restaurar dentes com extensa destruição coronal sem precisar recorrer à técnica tradicional de colocação de pinos intrarradiculares. As Endocrowns são coroas cerâmicas fixadas a um dente despolpado posterior, ancoradas na porção interna da câmara pulpar e nas margens da cavidade. Além da longevidade funcional, as Endocrowns são uma alternativa promissora tanto em relação à estética como na devolução da função de molares tratados endodonticamente. Neste trabalho foi apresentada uma revisão de literatura e um caso clínico sobre Coroas Endodônticas Adesivas, mais conhecidas como Endocrowns. Possui como objetivo abordar as principais indicações e vantagens desse tratamento restaurador, além de descrever o protocolo clínico mais recomendado para a confecção de uma Endocrown. A revisão de literatura foi realizada por meio de um levantamento bibliográfico on line de artigos científicos e o relato de caso clínico foi desenvolvidos na clínica de Pós-Graduação na Universidade Federal de Santa Catarina.With the advent of adhesive technology, it became possible to restore teeth with extensive coronal destruction without resorting to the traditional technique of placing intraradicular posts. The Endocrowns are ceramic crowns fixed at a later pulped tooth, which are anchored in the pulp chamber and the edges of the cavity. In addition to the functional longevity, the Endocrowns are a promising alternative both in terms of aesthetics and in term of the return of the molars endodontically treated function. This paper presents a literature review and a clinical case analysis of adhesive endodontic crowns (a.k.a. Endocrowns). The aim to approach the main indications and advantages of this restorative treatment and describe the most recommended clinical protocol for the use of an Endocrown. The literature review has been conducted through a online literature of scientific articles and the clinical case report was developed at the Graduate clinic at the Federal University of Santa Catarina

Méthodes d’évaluation des restaurations coronaires de la dent dépulpée : revue de la littérature

Les techniques de restaurations prothétiques passent par des phases in vitro et ensuite in vivo. Parmi tous les challenges opposés au chirurgien-dentiste, la restauration de la dent dépulpée est un réel challenge du fait des modifications de l’organe dentaire, et surtout des pertes de substances associées à ce traitement. Ce travail cherche à déterminer quels sont les critères les plus pertinents pour étudier ces thérapeutiques in vivo. Une étude de la bibliographie sur les dix dernières années nous a permis de comparer les différentes grilles d’évaluation permettant l’évaluation des restaurations coronaires de la dent dépulpée tant au niveau de la survie qu’au niveau de la qualité de ces restaurations. Les résultats nous montrent que les moyens d’évaluation sont très hétérogènes et pour la plupart d’entre eux présentent de nombreuses faiblesses méthodologiques, menant à une difficulté importante pour comparer les études. Le manque de précision des méthodes évaluatives et le non recouvrement des critères d’évaluation ne permettent pas une évaluation précise et pertinente des restaurations. Lors de l’évaluation des restaurations coronaires la mise en place de critères et de procédures standardisés est recommandée. L’évaluation devrait porter aussi bien sur la restauration en elle-même que sur les fonctions qu’elle permet de restaurer. De plus l’indépendance entre l’évaluateur et le praticien doit être recherchée et l’utilisation d’outils de mesure objectifs doit être privilégiée

Прояв різних типів руйнування під квазістатичним стиском стоматологічних ортопедичних конструкцій

Acoustic emission (AE) signals obtained from quasi-static compression tests on different dental materials and tooth-endocrown constructions were processed by continuous wavelet transform technique. By energy criterion three types of fracture were identified: plastic deformation, micro- and macrocracking (brittle fracture). Parameters including the frequency peak, bandwidth, pulsewidth and energy of AE signals were analyzed

Endocoroa em pré-molar utilizando cerâmica reforçada por dissilicato de lítio: um relato de caso

This study reported a clinical case about restoration of an endodontically treated tooth using an endocrown in lithium disilicate-reinforced ceramic fabricated by CAD/CAM system. Case of a female patient, 48 years old who presented coronal fracture of an endodontically treated tooth. Restoration with endocrown in lithium disilicate-reinforced ceramic fabricated by CAD/CAM system was indicated. The crowns were evaluated using a California Dental Association (CDA) quality assessment system at baseline and at follow-up examination. Endocrown in lithium disilicate-reinforced ceramic fabricated by CAD/CAM system was a reliable restorative alternative for an endodontically treated premolar. The minimally invasive prepare for endocrown preserves maximum tooth structure as a gold standard for tooth restorations. In addition, such restorative alternative is advantageous in comparison to conventional full post-and-core supported crown since it presents appropriate mechanical performance and longevity as a lower cost and faster clinical procedure.Este caso clínico descreve a restauração de um dente tratado endodonticamente com uma endocoroa em cerâmica de dissilicato de lítio fabricada pelo sistema CAD/CAM. O caso é de uma paciente do sexo feminino, 48 anos, que apresentava fratura coronária de um dente tratado endodonticamente. Uma restauração com endocoroa em dissilicato de lítio fabricada pelo sistema CAD/CAM foi indicada. As coroas foram avaliadas usando um sistema de avaliação de qualidade da Associação Dental da Califórnia e exame de acompanhamento. Uma endocoroa cerâmica em dissilicato fabricada por CAD/CAM foi uma alternativa de tratamento restaurador confiável para um pré-molar tratado endodonticamente. O preparo minimamente invasivo para endocoroa que preserva o máximo de estrutura dentária é considerado padrão ouro para restaurações dentárias. Ainda, tal alternativa restauradora é mais conservadora em comparação à coroa total com retentor intrarradicular e apresenta apropriado desempenho mecânico e longevidade com um menor custo e rapidez no preparo

Fracture resistance and failure modes of maxillary premolars restored with different endocrown designs and materials after artificial aging

Endocrowns have been used successfully for molars. However, they are still questionable for premolars due to their limited surface area for bonding. This study aimed to evaluate the effect of different designs and materials on the fracture resistance of maxillary premolar endocrowns. Three different endocrown designs and two ceramic materials were studied. Conventional post-and-core crowns served as control. Fifty-six maxillary premolars were endodontically treated and shortened to a level of 2 mm from the cervical line. They were randomly allocated into six endocrowns groups of two ceramic materials and three preparation designs: flat occlusal table with no ferrule design, 1.5 mm circumferential ferrule, and 1.5 mm buccal ferrule only. A post-and-core crown control group was designed with 1.5 mm ferrule, zirconia posts, and composite resin cores and lithium disilicate crowns. All restorations were bonded using Panavia V5 and subjected to a thermo-mechanical fatigue test with a 10 kg dynamic load for 1,200,000 cycles and thermocycling between 5 and 55 °C. The fracture resistance ranges from a minimum of 661 (± 143) N to a maximum of 1440 (± 316) N. Within the same material group, the designs showed a highly significant effect (p≤ 0.001), while the effect of a material variable within the same design was dependent on the design used. The ferrule design improved the fracture resistance of the specimens and were comparable to the post-and-core crown control group (p>0.05). The buccal ferrule groups fracture strength values were significantly lower than those of the control group (p≤0.001). The zirconia endocrowns with a flat occlusal table showed significantly higher fracture resistance than lithium disilicate endocrowns (p=0.001). Only two post-and-core samples revealed a favorable failure, all other specimens showed catastrophic failure modes

Should adhesive debonding be simulated for intra-radicular post stress analyses?

Orientador: Valentim Adelino Ricardo BarãoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: As análises computacionais de tensões em restaurações intracanais por vezes apresentam incoerências com estudos clínicos e in vitro. Ao avaliar padrões de fratura e resistências à fratura, os dados obtidos tanto em estudos clínicos quanto in vitro costumam não corresponder claramente com o desempenho previsto computacionalmente. Visto que a perda de adesão entre dente e restauração antecede a falha catastrófica in vitro, a inclusão e entendimento desse comportamento em estudos computacionais pode se fazer necessário para melhor correlação com os dados experimentais. Objetivos: Elucidar a influência da perda de adesão em restaurações intracanais e suas consequências na distribuição e valores máximos de tensões. Material e métodos: Cinco diferentes tipos de restaurações intracanais foram avaliadas através da análise por elementos finitos: MP = núcleo metálico fundido; GP = pino de fibra de vidro; PP = pino metálico pré-fabricado; RE = endocrown em resina; CE = endocrown em cerâmica em corpo único. Dois preparos cervicais foram considerados: sem férula (f0) e férula de 2 mm (f1). A simulação foi realizada em três etapas: (1) todos os contatos colados; (2) falha de adesão entre coroa e dente; (3) falha de adesão entre coroa, pino intracanal e dente. Contatos friccionais e separação entre as interfaces foram modeladas onde a falha de adesão foi simulada. As razões de tensões obtidas pela teoria de Mohr-coulomb (?MC ratio) e fator de segurança em fadiga (SF) para dentina foram comparadas com valores disponíveis na literatura de resistência a fratura, vida em fadiga e padrões de fratura em dentes com restaurações intracanais. Resultados: Os valores de ?MC ratio não apresentaram diferenças entre os grupos na primeira etapa. A segunda etapa provocou aumento do ?MC ratio em região de férula quando comparado com a primeira etapa. Na terceira etapa, ?MC ratio e SF para os modelos f0 foram altamente influenciados pelo material do material restaurador. Os modelos CE e RE apresentaram os maiores valores de ?MC ratio e menor SF. O grupo MP apresentou o menor ?MC ratio e maior SF. Os modelos f1 não mostraram diferenças relevantes na terceira etapa. Conclusão: A análise por elementos finitos apresentou melhor semelhança à literatura quando o contato friccional para restaurações intracanais é simulado. Resultados de análises onde todos os contatos são simulados como unidos devem ser considerados com cautelaAbstract: Computational stress analyses of intra-radicular restorations sometimes seem to contradict in vitro and clinical studies. When evaluating fracture patterns and ultimate strength, the obtained data from in vitro and clinical studies usually do not correspond to the behavior observed by computational methods. As the adhesion loss between tooth and restoration precedes the catastrophic failure in vitro, the addition and understanding of this behavior in computational studies could be necessary for better correlation to experimental data. Objectives: To elucidate the influence of debonding on stress distribution and maximum stresses for intra-radicular restorations. Methods: Five intra-radicular restorations were analyzed by finite element analysis: MP = metallic cast post core; GP = glass fiber post core; PP = pre-fabricated metallic post core; RE = resin endocrowns; CE = single piece ceramic endocrown. Two cervical preparations were considered: no ferule (f0) and 2 mm ferule (f1). The simulation was conducted in three steps: (1) intact bonds at all contacts; (2) bond failure between crown and tooth; (3) bond failure among tooth, post and crown interfaces. Contact friction and separation between interfaces was modeled where bond failure occurred. Mohr-coulomb stress ratios (?MC ratio) and fatigue safety factors (SF) for dentin structure were compared with published strength values, fatigue life, and fracture patterns of teeth with intra-radicular restorations. Results: The ?MC ratio was similar for all restorations types at first step. The second step increased ?MC ratio at the ferule compared to step 1. At the third step, the ?MC ratio and SF for f0 models were highly influenced by post material. CE and RE models had the highest values for ?MC ratio and lower SF. MP had the lowest ?MC ratio and higher SF. The f1 models showed no relevant differences among them at the third step. Conclusion: Finite element analysis most closely predicted failure performance of intra-radicular posts when frictional contact was modeled. Results of analyses where all interfaces are assumed to be perfectly bonded should be considered with cautionDoutoradoProtese DentalDoutor em Clínica OdontológicaCAPE

Restoration of Endodontically Treated Anterior Teeth by Modified Conservative Endocrowns: A Case Report with a 30-Month Follow Up

Objectives Restoration of severely damaged endodontically treated anterior teeth typically poses a challenge. Specific indication of post-retained restorations in such teeth has reasonably been questioned because of the potential tooth structure weakening. The present study aimed to describe a modified conservative endocrown (modified refers to intracanal extension while conservative refers to preparation at the finish line) to rehabilitate severely damaged anterior teeth. Case: Endodontically treated lower right central incisor had inadequate remaining tooth structure and restored by endocrwn restoration as a definitive treatment and followed for 30 month. Conclusion Considering the clinical outcome after 30 months of follow-up, it seems that this specific type of endocrown could efficiently serve as a conservative treatment approach to restore endodontically treated anterior teeth