Adhesive procedures have changed the way to restore endodontically treated teeth (ETT). It started with the shift from cast post-and-core to fiber post. The original focus on strength also shifted towards failure modes, revealing that catastrophic failures are still a concern when restoring endodontically-treated teeth even with fiber posts. As an alternative, postless approaches have been proposed in order to improve the chances of repair. The goal of this critical review is to present a survey of the current knowledge on adhesive approaches to restore endodontically treated teeth with and without extensive coronal tissue loss. The preservation of tooth structure of endodontically treated teeth is paramount. Partial versus full coverage of ETT, the role of the ferrule, the post type effect on catastrophic failures and postless alternatives as endocrowns and postless build-ups are reviewed. There is a consensus that the remaining tooth structure plays an important role in ETT survival, although the current literature still is contradictory on the influence of post type on root fractures as well as the benefits of avoiding a post or partially restoring a tooth. More clinical studies should be carried out with the modern postless adhesive alternatives to conventional approaches.
The delivery of laminate veneers using a direct restorative composite rather than a resin cement resulted in significantly less chipping and fractures, higher fracture strength in both accelerated fatigue and load-to-failure.
ObjectiveThe aim of the present study was to analyze the influence of root canal and glass
fiber post diameters on the biomechanical behavior of the dentin/cement/post
interface of a root-filled tooth using 3D finite element analysis. Material and MethodsSix models were built using micro-CT imaging data and SolidWorks 2007 software,
varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and
P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm;
C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was
conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied
to the palatal surface of the central incisor. The periodontal ligament surface
was constrained on the three axes (x=y=z=0). Maximum principal stress
(σmax) values were evaluated for the root dentin, cement layer, and
glass fiber post. Results:The most evident stress was observed in the glass fiber post at C3P1 (323 MPa),
and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress
on the root dentin was almost constant in all models with a peak in tension at
C2P1 (64.5 MPa). ConclusionThe greatest discrepancy between root canal and post diameters is favorable for
stress concentration at the post surface. The dentin remaining after the various
root canal preparations did not increase the stress levels on the root.
This study aimed to evaluate the influence of the type of prosthetic abutment associated to different implant connection on bone biomechanical behavior of immediately and delayed loaded implants. Computed tomography-based finite element models comprising a mandible with a single molar implant were created with different types of prosthetic abutment (UCLA or conical), implant connection (external hexagon, EH or internal hexagon, IH), and occlusal loading (axial or oblique), for both immediately and delayed loaded implants. Analysis of variance at 95%CI was used to evaluate the peak maximum principal stress and strain in bone after applying a 100 N occlusal load. The results showed that the type of prosthetic abutment influences bone stress/strain in only immediately loaded implants. Attachment of conical abutments to IH implants exhibited the best biomechanical behavior, with optimal distribution and dissipation of the load in peri-implant bone.
Objetivo: apresentar um caso clínico de instalação de implante imediato em região de bifurcação após exodontia de molar com uma técnica de osteotomia alternativa com o preparo do sitio implantar previamente à remoção das raízes. Materiais e métodos: em dezembro de 2017, JNPS, 39 anos de idade, sexo masculino, compareceu à Faculdade de Odontologia com queixa do dente 46 fraturado sem sintomatologia dolorosa. Nos exames clínicos e radiográficos o dente 46 apresentava tratamento endodôntico, sem remanescente coronário e amplo septo inter-radicular que favorecia a instalação de implante imediato. A cirurgia ocorreu em fevereiro de 2018 com o preparo do leito do implante na região do centro do dente previamente à exodontia. Em seguida foi realizada a extração das raízes de forma minimamente traumática, visando preservar a estrutura circundante. Um implante Cone Morse 3,75x9mm (Titamax CM Cortical – Neodent, Curitiba, Brasil). O torque final de inserção foi de 20 N/cm e foi instalado o cicatrizador para procedimento cirúrgico de 1 estágio. Após 4 meses foi instalado o pilar protético (Pilar CM – Neodent, Curitiba, Brasil) com altura de 2,5 mm e nas sessões seguintes foram realizados os procedimentos para confecção de coroa metalocerâmica. Resultados: no acompanhamento de 12 meses após instalação do implante, verificou-se aspectos clínicos e radiográficos de normalidade, além de satisfação do paciente com o tratamento. Conclusão: a técnica utilizada facilita o preparo do leito receptor e a instalação de implante em condições de estabilidade favorável, podendo ser empregada em situações clínicas semelhantes.
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