Post and core: a new clinical perspective – myths and facts

Objective: The present study aims to describe a literature review on post and core restorations from a new clinical perspective in dentistry. Also, to define the best choice regarding the intraradicular retainer, material used, confection techniques and their possible failures, explaining the myths and the truths about them. Methodology: This literature review was conducted by leading health databases: Pubmed (https://www.ncbi.nlm.nih.gov/pubmed), SCIELO (www.scielo.org) e Google Scholar (https://scholar.google.com.br). The keywords for the textual search were: Denture, Partial, Fixed; Post and Core Technique; Dental Research; Dentistry. Inclusion criteria were: literature on the subject under study, literature of recent years, english and portuguese languages, laboratory and clinical studies, and systematic reviews. Literature Review: Post and core are defined as prosthetic elements that seek intraradicular retention to support prosthetic crowns or unitary restorations. The ideal shape of the intraradicular retainer should supplement the dental remnant, allowing the shape of a prepared tooth to receive a prosthetic crown. In conjunction of the dental remnant, they are responsible for dissipating and absorbing the forces developed during the chewing cycles, without deformation or damaging the minimal cement layer. Conclusion: The evolution of endodontic therapy enables a restoration with greater safety of treated teeth. However, it is necessary to consider the remaining dental structure, mainly because the posts do not provide reinforcement, only retention and resistance to the prosthetic crown.

Effect of glass-fiber post on the biomechanical behavior of teeth with direct veneers

Objective: This study aimed to evaluate the biomechanical behaviour of endodontically treated teeth with direct veneer that received or not intra-radicular glass fiber post by finite elements analysis. Material and methods: Six models were designed, varying the presence or absence of glass fiber post and the thickness of direct veneer (0.5, 0.7 and 1 mm). Tridimensional models of maxillary central incisors were obtained with CAD software, Rhinoceros 4.0, and transferred to CAE software, ANSYS 17.2, which a 100N load was applied in a 45° on the lingual surface to simulate functional movements. Geometry contacts were bonded, and the structures were isotropic, linear, elastics, and homogeneous. After coherence and convergence analysis of mashes, the chosen fail criterion was the maximum principal stresses. Results: For cement, glass fiber post, the stress distribution was similar independently of glass fiber post presence or veneer thickness. Models with glass fiber post had better stress distribution and lower values of maximum stress for inner dentin and veneers. Veneers with 0.5 and 1 mm had higher stress concentration areas. Conclusions: It can be concluded that glass fiber post is favorable for restored teeth with direct veneers, and very thin or very thick preparations can damage the biomechanical behavior of restorations.KeywordsDental veneers; Finite element analysis; Nonvital tooth; Post and core technique.

Monobloco – cimentação de pino e preenchimento em único passo em dente tratado endodonticamente

The literature reports several materials for the restoration of endodontically treated teeth, with coronal destruction that requires an intra-root fiber post to stabilize the prosthetic part. The intra-radicular post of composite resin reinforced with fiberglass can be used as retainers in rehabilitating endodontically treated teeth due to their adhesiveness, pleasing aesthetics, and elasticity module close to the dentin less wear on the remaining structure. This clinical case reports the step-by-step application of dual resin cement (Rebilda DC Dentine - Voco) used as the cementation material of the post and material for the filling core in a single step, in an upper right lateral incisor. Moreover, it describes the advantages and indications of the post-and-core technique, also called “monobloc” which can be used in both anterior and posterior teeth. This protocol minimizes the adhesive interfaces, the chair time, and the steps of the clinical procedure.

A Custom Made Post and Core Technique for Restoring Badly Broken Mandibular Posterior Tooth: A Case Report

The successful treatment of a badly broken tooth depends both on good endodontic therapy and prosthetic reconstruction of the tooth. Molars with almost total coronal destruction can be salvaged by the use of customized post and core. A number of methods have been suggested for making a cast post and core using two or more of the canals to increase retention of the prosthesis. This case report discusses a method to restore a structurally compromised, endodontically treated mandibular first molar using a customized cast post and core.

Propriedades Mecânicas dos Pinos Intrarradiculares e sua Influência na Fratura de Dentes Tratados Endodonticamente

O objetivo deste trabalho é revisar a literatura acerca das propriedades mecânicas dos retentores intrarradiculares (RI), focando no núcleo metálico fundido (NMF) e pino de fibra de vidro, e em como influenciam na fratura de dentes tratados endodonticamente. Foi realizada busca na base de dados Pubmed, utilizando os descritores Post and Core Technique, Crowns e Dental Stress Analysis, onde 368 artigos foram encontrados e 5 selecionados. Os critérios de inclusão foram artigos publicados nos últimos 10 anos, na língua inglesa, estudos in vitro e que analisassem as propriedades mecânicas dos RI de interesse, sendo excluídos outros tipos de estudo e estudos in vitro que utilizassem dentes de animais. Forças verticais aplicadas em dentes com NMF causam estresse na raiz dental, principalmente na região apical, pois RI que possuem maior flexibilidade e menor rigidez promovem uma distribuição uniforme de tensões no dente, criando uma unidade mecanicamente homogênea e reduzindo o risco de fratura da raiz. Dessa forma, o pino de fibra de vidro é considerado mais favorável em termos de distribuição de tensão, devido ao módulo de elasticidade ser semelhante ao da dentina. É fundamental, portanto, que o cirurgião-dentista conheça as propriedades mecânicas desses materiais a fim de optar pelo tratamento mais indicado na restauração de dentes tratados endodonticamente.Palavras-chave: Post and Core Technique. Crowns. Dental Stress Analysis.

Push-out bond strength of glass fiber posts luted with two resin cements

<p class="CorpoA"><strong>Objective.</strong> To evaluate the bond strength of a prefabricated glass fiber post to the root dentin with two resin cements using the push-out test. <strong>Material and Methods.</strong> Thirty fiber posts (White Post ECD) were cemented in human endodontically treated anterior teeth with two resin cements (n=15): Relyx^TMARC and AllCem. The roots were transversely sectioned and divided in cervical, middle and apical thirds after 48 h of cementation. The specimens' retention was tested by push-out method. The results were analyzed by 2-way ANOVA and Tukey’s test (<em>p</em>&lt;0.05). <strong>Results.</strong> There were no significant differences in the bond strength between the resin cements. The bond strength was higher in cervical third than in middle and apical thirds for both resin cements. It was observed higher percentages of adhesive failures followed by mixed. <strong>Conclusions.</strong> Both resin cements are indicated in the cementation of glass fiber post.</p><p class="CorpoA"><strong>Keywords</strong></p><p class="CorpoA">Dental prosthesis; Post and core technique; Biomechanical phenomena.</p>

Knowledge and attitudes of students and dentists about the use and cementation of intra-radicular posts

<p><strong>Objective:</strong> The aim of the study was assess the knowledge and attitudes of students and dentists about the use and cementation of intra-radicular posts. <strong>Material and Methods:</strong> This cross-sectional study interviewed 150 students and 150 dentists in the city of XXXXXXXXX (Brazil). A questionnaire containing questions regarding restorative choice in teeth with large coronal destruction, level of confidence for the use of post and resin cement, function of intra-radicular posts and social-demographic characteristics was applied. Data were analysed using descriptive analysis and associations were tested through logistic regression using 95% confidence intervals. <strong>Results: </strong>The analysis showed that students presented an odd to choose prefabricated posts 127% greater than the dentists for anterior teeth, 105% greater to choose self-adhesive resin cement and 46% greater to choose conventional resin cement. Considering posterior teeth, students presented an odd to choose prefabricated posts 40% smaller than the dentists and an odd 51% greater to choose conventional resin cement. <strong>Conclusion:</strong> The formation level (students or dentists) was directly related to clinical choices of the interviewed. The use of prefabricated posts seems to be related to the location of the tooth in the arch, with pre-fabricated posts being more indicated for anterior teeth. Use of pre-fabricated posts in teeth with large coronal destruction is accepted in the literature. However, dentists are still not confident to use of pre-fabricated fiber posts especially in posterior teeth with large coronal destruction.</p><p><strong>Keywords</strong></p><p>Resin cements; Post and core technique; Health knowledge, attitudes, practice.</p>

Restoration of highly mutilated endodontically treated multi-rooted teeth using customized interlocking post & core : A case report

An endodontically treated teeth should have a good prognosis. It can resume full function and serve satisfactorily as an abutment for a fixed dental prosthesis (FDP) or a removable partial dental prosthesis. However, special techniques are needed to restore such a tooth. There are various techniques of post and core advocated in the literature. This case report presents the restoration of highly mutilated endodontically treated multi-rooted teeth using customized interlocking post and core technique.