Evidence map›Paper›PMID 42286599›Full record

ArticleBMC oral health2026

Fracture behavior of endodontically treated premolars restored with direct and indirect restorations: an in vitro study.

Esraa Abdel Ghaffar El Gezawy, Samar Saeed Bedair, Khaled Farouk Abbas, Somaya Algizawi, Raghda Kamh

Abstract read
In one paragraph

Article in BMC oral health, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Esraa Abdel Ghaffar El GezawyConservative and restorative dentistry department, Faculty of Dentistry, Galala University, Suez, Egypt. esraa.elgizawy@gu.edu.eg.ORCID 0000-0002-1468-6491
Samar Saeed BedairFixed Prosthodontics Department, Faculty of Oral and Dental Medicine, Egyptian Russian University, Cairo, Egypt.ORCID 0009-0008-9011-0700
Khaled Farouk AbbasEndodontics Department, Faculty of Oral and Dental Medicine, Egyptian Russian University, Cairo, Egypt.ORCID 0000-0002-2546-7884
Somaya Algizawi, Riyadh, Saudi Arabia.ORCID 0000-0003-3381-9437
Raghda KamhConservative and restorative dentistry department, Faculty of Oral and Dental Medicine, Egyptian Russian University, Cairo, Egypt.ORCID 0000-0001-9622-0689

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundEndodontically Treated Teeth (ETT) have challenges in resisting fracture against occlusal forces. This study aimed to assess the fracture resistance (FR) of endodontically treated premolar teeth restored with an innovative self-adhesive bulk-fill resin-based composite (RBC) (Stela , SDI Limited, Australia), a short-fiber-reinforced composite (SFRC) (EverX flow, GC., Tokyo, Japan), a conventional nanohybrid (RBC) (Filtek Z250 XT, 3M ESPE, St. Paul, MN, USA) , and a Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) Lithium Disilicate (Emax, Dentsply Sirona, Bensheim, Germany) Endocrown.

methodsFor the FR test, 44 human extracted maxillary premolars were included in the study. Endodontic treatment was done, and a single operator prepared standardized mesio‑occlusal‑distal (MOD) cavities in the teeth and divided into four groups (n=11) according to the restorative material used. Group (F1): ETT restored with Stela resin-based composite, which was inserted into the cavity as a single 5 mm increment. Group (F2): ETT restored with (EverX Flow) composite,which was packed and light-cured for 20 seconds, leaving a 2 mm occlusal layer to be restored with nanohybrid composite (Filtek Z250 XT). Group (F3): ETT restored with Filtek Z250 XT resin-based composite only. Group (F4): ETT restored with (CAD/CAM Cerec MCXL) Lithium Disilicate endocrown, preparations were scanned with the Omnicam, and restorations were designed using CEREC Premium Software (version 4.4). For direct restoration groups the proximal walls were reconstructed by using a tofflemire matrix retainer and band. All restored teeth were subjected to FR testing using a universal testing machine ( Bluehill Lite Software on an Instron® / Each specimen's failure load was recorded in Newton). Each specimen was individually mounted on the computer-controlled machine equipped with a 5 kN load cell, with the acrylic block secured to the lower fixed head.

resultsStatistical analyses were conducted using SPSS 27®, GraphPad Prism®, and Microsoft Excel 2016. Data normality was assessed with the Shapiro-Wilk and Kolmogorov-Smirnov tests, which indicated a nonparametric distribution. Comparison between groups revealed a significant difference (P<0.0001), with Group F4 (Endocrown) demonstrating the highest performance (1427.73 ± 156.96), compared to all direct restoration materials. In contrast, there were no significant differences among the three direct restoration groups despite slight differences in their means. Group F2 (EverX+Z250, mean: 619.87 ± 186.41) was higher than Group F1 (Stella, mean: 561.75 ± 173.74) with P = 1.000, and higher than Group F3 (Z250, mean: 452.22 ± 202.72) with P = 0.471. Group F1 (Stella) exceeded Group F3 (Z250), but this difference was not statistically significant (P = 0.838).

conclusionsWhile lithium disilicate endocrowns exhibit superior fracture resistance, direct restorative materials may serve as a clinically acceptable alternative for routine applications. Nevertheless, these findings should be interpreted with caution, given the inherent limitations of the in vitro study design.

Indexed as

BicuspidDental Restoration, PermanentTooth FracturesTooth, NonvitalComposite ResinsComputer-Aided DesignDental MaterialsDental PorcelainDental Stress AnalysisHumansIn Vitro TechniquesMaterials TestingNanocompositesComposite ResinsDental MaterialsDental PorcelainEverX PosteriorFiltek Z250lithia disilicateCAD/CAMEndocrown restorationEndodontically treated premolarsFracture resistanceLithium DisilicateNnanohybrid resin-based compositeShort-fiber-reinforced resin-based composite

Identifiers

PMID42286599
PMCPMC13263949

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.