Fracture resistance and microleakage of anterior endocrowns: a systematic review of in vitro studies.

Effect of intraradicular fiber post on the fracture resistance of endodontically treated and restored anterior teeth: A systematic review and meta-analysis

A variety of non-metal prefabricated posts, including fiber posts, can be used as an alternative to metal posts due to their numerous feasible characteristics. Further research is necessary to assess physical and mechanical properties of restorations supported by intracanal posts in primary teeth. The aim of the study was to compare fracture resistance of maxillary central incisors that were extensively restored with glass fiber and composite posts. A total of 40 primary maxillary central incisors were randomly divided into 4 equal groups. Group 1 received conventional intracanal composite posts, group 2 was treated with prefabricated intracanal glass fiber posts, group 3 received precured intracanal composite posts, and group 4 was treated with intracanal lucent glass fiber posts. Crowns were restored using composite resin, and the specimens were subsequently exposed to 5,000 thermal cycles and progressive load at a crosshead speed of 0.5 mm/min until fracture. The fracture resistance values were compared via one-way analysis of variance (ANOVA) followed by Tukey's test for pairwise comparisons (α = 0.05). The highest fracture resistance was observed in the lucent post group (343.2 N), followed by the prefabricated glass fiber post (284.8 N), conventional composite post (270.3 N) and precured composite post (261.1 N) groups, respectively. A statistically significant difference in the mean fracture resistance was observed among the 4 groups (p < 0.05). Pairwise comparisons revealed that the mean fracture resistance of the lucent post group was significantly higher than that of the other groups (p < 0.05). All of the intracanal posts provided apt fracture resistance and can be used to restore severely damaged primary maxillary central incisors. However, lucent posts demonstrated significantly higher levels of fracture resistance.

ObjectivesThis systematic review aims to investigate the effect of different preparation designs on the marginal fit and fracture strength of ceramic occlusal veneers.Materials and MethodsBased on the PICO question and the search terms, an electronic search was performed in Google Scholar, PubMed (MEDLINE), Scopus, Cochrane Library, Web of Science, Science Direct, Wiley, Ovid, and SAGE for articles published up to July 2022. After including English in vitro studies that evaluated posterior ceramic occlusal overlays at the posterior with ceramic restorations by following the PRISMA statement, the extracted data was tabulated. The methodological quality of the included studies was evaluated. Risk of bias assessment was done independently by two authors using the modified MINORS scale.ResultsAbout 3138 search results were screened, of which 22 were selected due to their titles. Twenty‐one full‐text articles were assessed for eligibility. Seventeen in‐vitro studies were finalized for the extraction of quantitative data. All 17 articles had a low risk of bias and were retained. The influencing items for evaluating the research were different in most studies; therefore, qualitative synthesis of the results was feasible. They generally included preparation design, material thickness, depth of preparation in the tooth, internal divergence angle, and finish line. Meta‐analysis was not done due to heterogeneity of preparation types and evaluation methods. Results revealed that fracture resistance of occlusal veneers is higher than normal mastication force, and it is sufficient to prepare the occlusal surface, use a self‐etching primer for bonding, and an acceptable minimum ceramic thickness. The marginal discrepancy of occlusal veneers is clinically acceptable. However, this systematic review faces some limitations due to the lack of in vivo studies, different preparation designs in included studies, different follow‐ups, and lack of comprehensive explanations in articles.ConclusionsThe preparation design of occlusal veneers influences both marginal adaptation and fracture resistance. Various preparation designs are proven to have clinically acceptable fracture strength and marginal adaptation.

Scientific mapping of hotspots and trends of post and core research based on the Web of Science: A bibliometric analysis

Endocrown restorations have increased in popularity in recent years due to the advancement of both adhesive and restorative materials. The clinical success of endocrowns depends on several factors, including preparation design, material selection, fracture resistance, and marginal adaptation. The aim of this in vitro study was to compare the fracture strength of endocrown restorations fabricated from three different computer-aided design (CAD)/computer-aided manufacturing (CAM) materials. Thirty extracted mandibular first molars were selected. The teeth underwent conventional root canal treatment before being prepared for endocrown restoration. The teeth were allocated to three groups (n=10), corresponding to each of the three ceramic materials used to fabricate the endocrowns they would receive. The ceramic materials used were zirconia-reinforced lithium silicate glass-ceramic (VITA Suprinity, VITA Zahnfabrik, Bad Säckingen, Germany), polymer-infiltrated hybrid ceramic (VITA Enamic, VITA Zahnfabrik, Bad Säckingen, Germany), and lithium disilicate glass-ceramic (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein). The specimens were scanned, and the digital impressions were transferred into design software to construct the endocrowns. The endocrowns were then milled and cemented. A universal testing machine (5969L3504, Instron, USA) was used for the fracture strength test at a crosshead speed of 1 mm/min until catastrophic failure occurred. Statistical analysis was performed using IBM Corp. Released 2015. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp. The one-way analysis of the variance test indicated a significant difference in the fracture strength between the different ceramic groups tested (P=0.037). The Tukey posthoc test showed that the IPS e.max CAD group had marginally higher fracture strength values than the VITA Enamic group (P=055). No significant differences in fracture strength values were found between the VITA Enamic and VITA Suprinity groups or between the VITA Suprinity and IPS e.max CAD groups (P>0.05). The reported fracture strength values for all the tested materials were higher than the strength required to resist masticatory forces. Therefore, endocrowns fabricated using VITA Enamic, IPS e.max CAD, and VITA Suprinity CAD/CAM materials present restorations with a clinically acceptable fracture strength.

The aim of this study was to compare the stress distribution in radicular dentin of a maxillary canine restored with either a glass fiber post, carbon fiber post or an experimental dentin post using finite element analysis (3D-FEA). Three 3D virtual models of a maxillary canine restored with a metal-ceramic crown and glass fiber post (GFP), carbon fiber post (CFP), and experimental dentin post (DP) were obtained based on micro-CT images. A total of 180 N was applied on the lingual surface of the incisal third of each tooth at 45 degrees. The models were supported by the periodontal ligament fixed in three axes (x=y=z=0). The von Mises stress (VMS) of radicular dentin and the intracanal posts was calculated. The structures of all groups showed similar values (MPa) and distribution of maximum von Mises stress. Higher stress was found in the apical third of dentin while the posts presented homogeneous stress distribution along the axis. The fiber and dentin posts exhibited similar stress values and distribution. Thus, the experimental dentin post is a promising restorative material.

The opportunity of using Endocrown-type restorations in the current prosthetic dentistry practice as an alternative to other, well-established methods of corono-radicular restorations and the evolving palette of adhesive materials has made these restorations more popular in the last few years. The purpose is to review the available literature about Endocrown restorations regarding mechanical properties - fracture strength and resistance, survival rate, the preparation design - marginal and internal adaptation, and esthetics. The search was carried out on four databases: PubMed, Scopus (ScienceDirect), Web of Science, and Scielo using the following terms: "endocrowns", "endodontic crown", and" no buildup crown". Initially, a total of 163 articles published between 2015 and May 2021 were selected. After the duplicates, papers presented only as abstracts, articles in any other languages except English, and review articles were eliminated; a total of 72 articles remained to be considered for this review.After assessing the 72 considered articles, 37 were chosen as fit for this review. The reasons for the elimination of the other 35 articles were: their main focus was other than endocrowns, e.g., direct restorations, indirect restorations of vital teeth; case reports; study protocols. From the 37 articles selected, 34 were focused on mechanical properties, including the influence of the preparation design, and three on survival rate, of which one also had a point of view regarding esthetics. The literature included in this review shows that endocrowns perform similarly or even better in some cases than other coronal restorations. However, this statement must be interpreted cautiously, given that most articles were in vitro or finite element analysis studies. Given the high degree of conflicting results found in the articles included in this review, the authors consider as reasonable to conclude that further studies are needed to confirm the feasibility of endocrowns and the best choice of material.

Mechanical performance of endocrown restorations in anterior teeth: A systematic review and network meta-analysis

This systematic review and meta-analysis compares the fracture resistance of polyethylene fiber posts and prefabricated glass fiber posts in root canal-treated, single-rooted permanent teeth. By analyzing invitro studies, it addresses gaps in fiber post system research. A systematic search of PubMed, Web of Science, Scopus, Embase, and Cochrane Library (until May 2024) identified invitro studies comparing these post types. The risk of bias was assessed using Sarkis-Onofre etal. and Alhajj etal. A meta-analysis estimated pooled standardized mean differences (SMD) with 95% confidence intervals (CIs) (PROSPERO: CRD42022362407). Out of 622 studies, nine were included. Polyethylene fiber posts had significantly lower fracture resistance (SMD = -1.77, 95% CI: -2.98 to -0.57). Meta-regression showed no impact of force speed or load angle. Subgroup analysis highlighted significant effects of tooth type, storage media, post length, periodontal ligament (PDL) simulation, ferrule, and crown placement. Additionally, fractures in teeth restored with polyethylene fiber posts tended to be more repairable. Polyethylene fiber posts exhibited lower fracture resistance than prefabricated glass fiber posts. However, multiple factors influence outcomes, highlighting the need for further research and standardization.

Post and core crowns and endocrowns perform similarly on fracture strength, but endocrowns have more repairable fractures.

This systematic review aimed to investigate the fracture resistance and mode of failure of endodontically-treated permanent teeth restored with Ribbond posts (Ribbond, Inc.) compared with endodontically-treated permanent teeth restored with other post systems. A comprehensive, systematic literature search was carried out using several electronic databases: MEDLINE/PubMed, Google Scholar, and Cochrane Library. Two separate researchers were appointed to identify the studies meeting the eligibility criteria, and to perform the data extraction, risk of bias, and quality assessment. Twelve studies were included in the quantitative analysis. Meta-analysis was performed with 11 of the 12 included articles. The meta-analysis showed that Ribbond posts have a fracture strength less than prefabricated metal posts, cast metal posts, and prefabricated fiber posts and greater than custom e-glass fiber posts. Mode of failure analysis revealed that Ribbond posts have the most favorable non-catastrophic fractures. Although Ribbond posts have lower fracture resistance, their favorable mode of failure makes them potentially the most biomimetic post system.

The influence of customization of glass fiber posts on fracture strength and failure pattern: A systematic review and meta-analysis of preclinical ex-vivo studies

Learning How to Believe: Epistemic Development in Cultural Context

Objective The aim of this systematic review was to provide an overview of available scientific evidence regarding the comparative efficacy of computer-aided design (CAD) and computer-aided manufacturing (CAM) glass fiber posts with prefabricated and metal cast posts for the restoration of endodontically treated teeth (ETT). Methods This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic and manual searches were performed using the PubMed, SciELO, Cochrane, ScienceDirect, Web of Science, and EBSCO databases. The reference lists of the selected papers were reviewed to identify relevant papers. There were no year restrictions, and eligible studies were those in English publications and describing in vitro studies evaluating intraradicular retainers (IRs) for (i) fracture resistance, (ii) bond strength, (iii) adaptation, and (iv) cement layer thickness. Literature reviews, systematic reviews, meta-analyses, case reports, in vitro studies with <8 specimens, and noncomparative trials involving prefabricated or metal cast posts were excluded. The authors of this review independently screened the search results, extracted data, and assessed the risk of bias. Results No significant differences were found in fracture resistance between prefabricated and CAD/CAM glass fiber posts or between CAD/CAM glass fiber and metal cast posts, although the latter demonstrated higher fracture resistance than the prefabricated glass fiber posts. Restoration with a full crown was not necessary to increase the fracture resistance in the presence of the ferrule effect. CAD/CAM glass fiber and metal cast posts had higher bond strength, lower nanoleakage, and better adaptation to the root canal. Conclusions Despite the heterogeneity of methodologies and results reported, the results of these studies indicated that the CAD/CAM glass fiber and metal cast posts showed greater efficacy in terms of fracture resistance, retention, and adaptation, compared to prefabricated glass fiber posts.

The aim of this study was to evaluate the fracture resistance and marginal adaptation of endo-crown restorations produced from different resin-matrix ceramics (RMS) and the effects of these materials on marginal adaptation and fracture resistance. Three frasaco models were used by preparing (first) premolar teeth in three different margin preparations: butt-joint, heavy chamfer and shoulder. Each group was further divided into four subgroups according to the type of restorative material used: Ambarino High Class (AHC), Voco Grandio (VG), Brilliant Crios (BC) and Shofu (S) (n = 30). Master models were obtained using an extraoral scanner and fabricated with a milling machine. Marginal gap evaluation was performed with a silicon replica technique using a stereomicroscope. Replicas of the models (n = 120) were produced with epoxy resin. The fracture resistance of the restorations was recorded using a universal testing machine. The data were statistically analyzed using two-way ANOVA, and a t-test was applied for each group. Tukey’s post-hoc test was performed to compare significant differences (p ≤ 0.05). The highest marginal gap was observed in VG, and the best marginal adaptation and the highest fracture resistance were found in BC. The lowest fracture resistance in Butt-joint preparation design was found in S. In addition, the lowest fracture resistance value in the heavy chamfer preparation design was found in AHC. The heavy shoulder preparation design displayed the highest fracture resistance values for all materials.