Clinical and laboratorial performance of rehabilitation of endodontically treated teeth: A systematic review.

OBJECTIVE: This systematic review aimed to analyze the clinical (survival rate, failure risk, or fracture) and laboratory performance (fracture mode or failure) of rehabilitations of endodontically treated teeth, with and without posts. MATERIALS AND METHODS: A systematic search was conducted in the Pubmed, Scopus, Web of Science, Embase, Cochrane Library, and OpenGrey databases up to March 2023, according to PRISMA guidelines. In vitro and clinical studies that compared the clinical and laboratory performance of endodontically treated teeth with and without intraradicular posts were included. Studies selection, data extraction, and risk of bias analysis were performed. RESULTS: Thirty-one in vitro and 7 clinical studies were included. For in vitro studies, fiberglass post (n = 24) was the most mentioned. The follow-up time of the clinical studies ranged from 1 to 17 years, with the fiber-reinforced composite post (n = 3) being the most evaluated, and only failure risk proved to be more favorable for using intraradicular posts. CONCLUSION: Rehabilitations of endodontically treated teeth with and without intraradicular retainers showed no difference in fracture resistance and failure mode, evaluated by in vitro studies. Clinical studies showed no difference in survival rate, but failure risk proved to be more favorable for the use of posts. CLINICAL SIGNIFICANCE: This analysis revealed significant variability between results, however, most laboratory and clinical studies revealed no difference with using the post. Furthermore, it is important to emphasize the need to evaluate the coronary remnant and the general characteristics of the tooth in each situation.

Push-Out Bond Strength Assessment of Different Post Systems at Different Radicular Levels of Endodontically Treated Teeth.

This study assessed the bond strength of prefabricated post systems at different root levels of endodontically treated teeth. One-rooted human premolars (N = 70; n = 10) were cut to 2 mm above the cement-enamel junction. Root canals were treated and randomly assigned to one of the seven post systems: T: Titanium (Mooser), ZrO: Zirconia (Cosmopost), G: Fiber (FRC Postec Plus), E1: Fiber (Direct) (Everstick post), E2: Fiber (Indirect) (Everstick post), PP: Fiber (PinPost), and LP: Injectable Resin/Fiber composite (EverX Posterior). All posts were luted using a resin cement (Variolink II), and the roots were sectioned at the coronal, middle, and apical root levels. Push-out tests were performed in the Universal Testing Machine (0.5 mm/min). Data (MPa) were analyzed using two-way ANOVA and Tukey's tests (α = 0.05). The results showed that the bond strength (mean ± SD) of E2 posts were highest (5.3 ± 2.7) followed by PP (4.1 ± 2.0); G (4.0 ± 1.6); LP (2.6 ± 1.9): T (2.2 ± 1.5) and ZrO (1.9 ± 1.0) posts systems. No significant differences were found in bond strength of all post systems. The bond strength in the coronal root level was the highest with 3.6 ± 2.2 MPa. The bond strength of FRC post systems was significantly higher than those of rigid posts of titanium or ZrO2. Bond strength results were the highest in the coronal root level for all tested post systems but did not differ significantly from the other two root levels.

Resistance to fracture of intraradicular posts made of biological materials.

BACKGROUND: The aim was to analyze the fracture resistance of human teeth treated endodontically and restored with posts made of bovine dentin, human dentin, or glass fiber, and to evaluate the fracture pattern. METHODS: Cylindrical posts of 1.5 mm in diameter cemented to the roots of human maxillary canines presented a length of 15 mm, cervical diameter of 5-5.5 mm in the mesiodistal direction, and 7-7.5 mm in the vestibule-palatal direction. The groups studied were: Group I-10 glass fiber posts; Group II-10 human dentin posts; Group III-10 bovine dentin posts (self-adhesive resin cement); and Group IV-10 bovine dentin posts (resin-modified glass-ionomer cements). The coronal part of tooth was restored with a standardized core build-up using composite. All of the groups were submitted to a compression force test and the resistance to fracture was verified using a universal testing machine. The fracture pattern was likewise evaluated. RESULTS: The values of resistance to fracture were: 723.3N in group I, 561.5N in group II, 556.6N in group III, and, 613.27N in group IV. However, no statistically significant difference was observed among the groups. The fractures in groups I and II were most commonly found in the middle/apical third and were considered irreparable. For restored teeth in group III, half of the fractures appeared in the cervical third and were reparable. In group IV, all of the fractures were reparable, with the majority in the cervical thirds. CONCLUSION: Bovine dentin can be used as intraradicular post to substitute human dentin and glass fiber posts. The greater the malleability of the post, the greater the chances of survival of the teeth when subjected to fracture testing.

Surface treatments of a glass-fiber reinforced composite: Effect on the adhesion to a composite resin.

PURPOSE: To compare the effect of different surface treatments (pre-treatments and bonding agents) on the bond strength between glass-fiber post and composite resin, and the topographic alterations of the treated post surface. METHODS: Thirty-six glass-fiber blocks (12mm×10mm×8mm) were specifically manufactured for this study and randomly assigned into 12 groups considering two factors: 'pre-treatments' (-cleaning with 70% alcohol; air-abrasion with silica-coated aluminum oxide particles; 35% hydrogen peroxide) and type of 'bonding agent' (no bonding agent; application of Monobond Plus; RelyX Ceramic Primer; Single Bond Universal). After that, 6 cylindrical templates (1mm high×1mm Ø) were fixed on each block, filled with composite resin (n=18) and light-cured. Specimens were stored under 37°C for 24h and microshear tests (wire loop Ø=0.2mm) were performed. Topographic, roughness and failure analyses were also performed. RESULTS: Different surface pre-treatments led to different topographic and roughness alterations; a higher surface alteration was noted after silica particles air-abrasion, while a slight surface alteration in the hydrogen peroxide group and a smooth pattern were observed in the cleaning group. The factors 'pre-treatments' (p<0.05), 'bonding agent' (p<0.05) and their interaction (p<0.05) influenced the bond strength. Silica coating, apart from bonding agent application, or Single Bond Universal application without pre-treatment promoted the highest bond values. The main failure type was adhesive at the resin-post interface. CONCLUSIONS: In terms of pre-treatments, silica coating promotes the best bonding performance, but pre-treatments can be dispensable when applying Single Bond Universal.

Influence of elastic modulus of intraradicular posts on the fracture load of roots restored with full crowns / Influência do modulo de elasticidade de retentores intrarradiculares na carga para fratura de raízes restauradas com coroas totais

Objective: This study aimed to evaluate the fracture load and displacement of roots restored with posts of different elastic modulus. Material and method: Thirty-six replicas of epoxy resin mixed with glass microfibers were made from an endodontically-treated human premolar root prepared to a length of 12 mm with a custom drill, leaving the apical 4 mm unprepared. Replicas were randomly restored with (n = 12): FP-LM (fiber post with low elastic modulus- 50 GPa), FP-HM (fiber post with high elastic modulus - 67 GPa) and MP (metallic post - 208 GPa), using self-curing adhesive and dual resin cement. Cores were built up with composite resin and metallic crowns were cemented in all the roots with self-adhesive resin cement with self-curing mode. Specimens were subjected to a fracture load test (45° inclination/0.5 mm/min) and displacement was registered at 100 N. Result: One-way ANOVA showed that elastic modulus of the post did not affect the fracture load means (p = 0.203) (FP-LM: 237.4 ± 65.11 N; FP-HM: 236.7 ± 92.85 N; MP: 295.8 ± 108.7 N) but was statistically significant for the displacement (p < 0.00): Tukey's test showed that FP-LM displacement mean (0.81 ± 0.15 mm) was significantly higher than those for FP-HM (0.46 ± 0.26 mm; p = 0.00) and MP (0.62 ± 0.07 mm; p = 0.04). Conclusion: Posts with different elastic modulus exhibit similar fracture loads, but a lower displacement is achieved when fiber posts with a high elastic modulus and metallic posts are used.

Objetivo: Este trabalho avaliou a carga para fratura e deslocamento de raízes restauradas com pinos de diferentes módulos de elasticidade. Material e método: Trinta e seis réplicas de microfibras de vidro embutidas em resina epóxi foram fabricadas a partir de uma raiz de um pré-molar tratado endodonticamente preparado em 12 mm de comprimento com brocas customizadas, deixando 4 mm apicais sem preparo. As raízes foram randomicamente restauradas com (n = 12): FP-LM (pino de fibra com um baixo módulo de elasticidade - 50 GPa), FP-HM (pino de fibra com um alto módulo de elasticidade - 67 GPa) e MP (pinos metálicos - 208 GPa), usando adesivo autopolimerizável e cimento resinoso dual. Núcleos foram confeccionados com resina composta e coroas metálicas foram cimentadas em todas as raízes com cimento resinoso autoadesivo com modo de polimerização químico. Os espécimes foram submetidos ao teste de fratura em 45° (inclinação de 45° / 0,5 mm/min) e o deslocamento foi registrado aos 100 N. Resultado: Anova 1 fator mostrou que o módulo de elasticidade dos retentores não afetou as médias de fratura (p = 0,203) (FP-LM: 237,4 ± 65,11 N; FP-HM: 236,7 ± 92,85 N; MP: 295,8 ± 108,7 N) mas foi estatisticamente significante para o deslocamento (p < 0,00): o teste de Tukey mostrou que a média de deslocamento do grupo FP-LM (0,81 ± 0,15 mm) foi significativamente maior do que o grupo FP-HM (0,46 ± 0,26 mm; p = 0,00) e MP (0,62 ± 0,07 mm; p = 0,47). Conclusão: Pinos com diferentes módulos de elasticidade mostram resistência similar, porém um menor deslocamento é obtido quando pinos de fibra com alto módulo de elasticidade (FP-HM/MP) são usados.

Assessment of a Cavity to Optimize Ultrasonic Efficiency to Remove Intraradicular Posts.

INTRODUCTION: The study assessed an in vitro protocol for the removal of cast metal posts using ultrasonic vibration in multirooted teeth by drilling a cavity in the coronal portion of the post followed by ultrasound application in the cavity. METHOD: Forty endodontically treated molars received intraradicular cast posts and were divided into 4 groups according to the removal protocol: the control group, no cavity and no ultrasonic vibration; the ultrasonic group, no cavity and ultrasonic vibration in the coronal portion of the core; the cavity group, a cavity in the core and no ultrasonic vibration; and the cavity ultrasonic group, a cavity in the core and ultrasonic vibration inside the cavity. The traction test was performed on all samples using a universal testing machine (EMIC DL-2000; EMIC Equipamentos e Sistemas de Ensaio LTDA, São José dos Pinhais, PR, Brazil) at a speed of 1 mm/min, obtaining values in Newtons. The data were statistically analyzed using analysis of variance and the Tukey-Kramer test (P < .05). RESULTS: The results showed statistically significant differences between the tested groups (control group = 322.74 N, ultrasonic group = 283.09 N, cavity group = 244.00 N, and cavity ultrasonic group = 237.69 N). The lowest mean strength was found in the group that received ultrasonic vibration inside the cavity. CONCLUSIONS: Preparing a cavity in the coronal core followed by ultrasonic vibration reduces the traction force required for removal. The removal protocol was effective for removing posts in multirooted teeth cemented with zinc phosphate.

Endocrown restorations: A systematic review and meta-analysis.

OBJECTIVES: A systematic review was conducted to evaluate clinical (survival) and in vitro (fracture strength) studies of endocrown restorations compared to conventional treatments (intraradicular posts, direct composite resin, inlay/onlay). DATA: This report followed the PRISMA Statement. A total of 8 studies were included in this review. SOURCES: Two reviewers performed a literature search up to February 2016 in seven databases: PubMed, Web of Science, Scopus, BBO, SciELO, LILACS and IBECS. STUDY SELECTION: Only clinical trials and in vitro studies that evaluated endocrowns were included. Case reports, case series, pilot studies, reviews and in vitro studies that evaluated properties other than fracture strength of endocrowns were excluded. From the 103 eligible articles, 8 remained in the qualitative analysis (3 clinical trials and 5 in vitro studies), and the meta-analysis was performed for the 5 in vitro studies. A global comparison was performed with random-effects models at a significance level of p<0.05. RESULTS: Clinical trials showed a success rate of endocrowns varying from 94 to 100%. The global analysis in posterior and anterior teeth demonstrated that endocrowns had higher fracture strength than conventional treatments (p=0.03). However, when comparing endocrowns to conventional treatments only in posterior teeth (subgroup analyses), no statistically significant differences were found between treatments (p=0.07; I(2)=62%). CONCLUSION: The literature suggests that endocrowns may perform similarly or better than the conventional treatments using intraradicular posts, direct composite resin or inlay/onlay restorations. CLINICAL SIGNIFICANCE: Although further studies are still necessary to confirm the present findings, endocrowns show potential application for the rehabilitation of severely compromised, endodontically treated teeth.

Restoration of endodontically treated teeth

The restoration of endodontically treated teeth is one of the most challenging situations of the dentist`s clinical practice, because it involves procedures related to several areas, such as Endodontics, Operative Dentistry, and Prosthetics. These restorations aim to replace the structures lost during endodontic surgery and access to both the pulp chamber and root canal system during the instrumentation, as well as the removal of the carious tissue and temporary restorations. It is also important to remember that the prognosis of endodontically treated teeth depends not only on endodontic treatment success itself, but also on the amount of remnant tooth tissue and the definitive restoration that will be placed onto the dental element.

Retratamento endodôntico de dentes com contenção intrarradicular:orientação clínica / Endodontic retreatment of teeth restored with intraradicular posts: clinical orientation

Objetivo: Tendo em vista orientar os profissionais da odontologia na conduta clínica, o presente trabalho propôs-se a criação de uma tabela com situações clínicas contendo sugestões de tratamento em relação às possíveis falhas ocorridas tanto na adaptação da contenção intrarradicular quanto no tratamento endodôntico. Material e método: Foram avaliadas as condições de tratamento no âmbito clínico e radiográfico e discutidas as possíveis soluções de tratamento mais viáveis para os respectivos problemas. A tabela foi construída levando-se em consideração a experiência profissional dos alunos de oito edições do curso de especialização em endodontia da Faculdade de Odontologia da Universidade Federal de Uberlândia, no período de 1995 a 2010. Resultados: Na condição satisfatória do pino, sua remoção só foi indicada onde se observa tratamento endodôntico insatisfatório e lesão periapical presente. Na condição insatisfatória do pino, sua remoção foi indicada independente da qualidade do tratamento endodôntico, e após a remoção o retratamento endodôntico foi também indicado, independente da presença ou não de lesão periapical. O fator determinante na indicação da cirurgia parendodôntica foi a presença da lesão periapical e mesmo assim foi indicada a proservação clínica e radiográfica antes da cirurgia. Conclusões: Caso ocorra o insucesso do tratamento de um dente com canal tratado e restauração coronária com pino intracanal, a conduta clínica a ser tomada dependerá de vários fatores, dentre eles a presença de lesão periapical, a extensão da obturação e a qualidade da restauração coronária, principalmente com relação ao comprimento e diâmetro do pino intrarradicular.

Aim: To guide dentists in their clinical practice, the present study presents a table list of clinical situations and treatment suggestions related to possible failures in both post adaptation and endodontic treatment. Methodology: Work conditions were evaluated in both clinical and radiographic aspects and the most viable treatment solutions were discussed. The table was built considering the professional experience of the students throughout eight editions of the endodontics specialization course in the Federal University of Uberlandia, from 1995 to 2010. Results: When the post?s condition was considered acceptable, its removal was only indicated when the endodontic treatment was considered inacceptable and there was a presence of periapical lesion. If the post?s situation was considered inacceptable, its removal was indicated regardless of the endodontic treatment?s quality, and after post?s removal, endodontic retreatment was also indicated in the presence or absence of periapical lesions. The determinant factor to indicate periapical surgery was the presence of periapical lesion and, even so, its indication was considered a secondary procedure. Conclusions: If a treatment failure of an endodontic treated tooth with an intracanal retained coronal restoration occurs, the clinical conduct will depend on several factors such as: presence of perapical lesion, extend of the root canal filling and quality of coronal restauration, mainly with relation to the length and diameter of the intracanal post.