Evidence map›Paper›PMID 42346691›Full record

ArticleJournal of functional biomaterials2026

Flexural Strength and Clinical Classification of Different Layers in 4/5Y-PSZ Zirconia Materials.

Ulrich Lohbauer, Margit Schwarz, Renan Belli

Abstract read
In one paragraph

Article in Journal of functional biomaterials, 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

3 authors.

Ulrich LohbauerResearch Laboratory for Dental Biomaterials, Department for Operative Dentistry and Periodontology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Glueckstrasse 11, 91054 Erlangen, Germany.ORCID 0000-0002-9862-0886
Margit SchwarzResearch Laboratory for Dental Biomaterials, Department for Operative Dentistry and Periodontology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Glueckstrasse 11, 91054 Erlangen, Germany.
Renan BelliResearch Laboratory for Dental Biomaterials, Department for Operative Dentistry and Periodontology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Glueckstrasse 11, 91054 Erlangen, Germany.ORCID 0000-0003-0913-3996

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Multilayer 4Y/5Y-PSZ zirconia materials have been developed to combine strength and translucency in monolithic "all-in-one" dental restorations. This study evaluated the flexural strength of different layers (incisal, transition, and dentin) in four commercially available multilayer zirconia systems using three-point bending tests in accordance with ISO 6872. A total of 360 CAD/CAM-fabricated bar-shaped specimens were prepared from the materials CE (Cercon yo ML, DentsplySirona), KA (Katana YML, Kuraray Noritake), PZ (3D ProZir, Aidite), PE (IPS e.max ZirCAD Prime esthetic), and assigned to layer-specific groups based on their position within the discs. After sintering and standardized surface finishing, specimens were tested under three-point bending conditions. Fracture strength was calculated and statistically analysed. Microstructural and fractographic analyses were performed to assess grain structure and to identify fracture origins. The results demonstrated significant differences in flexural strength both among materials and between layers. In general, dentin layers exhibited the highest strength, reaching mean values up to 1143 MPa, while incisal layers showed significantly lower values, with minima around 572 MPa. Only one material (CE) maintained flexural strength above the ISO threshold of 800 MPa across all layers, qualifying for unrestricted (class 5) clinical use. Other materials showed limitations, particularly in the more translucent incisal regions (KA, PE). One material fell below the ISO threshold (PZ). Weibull moduli revealed differences in reliability, with moduli ranging from 4.7 to 16.5. Fractographic evaluation identified typical fracture patterns such as surface grinding defects and internal porosity, but no abnormal fracture origins. The strength gradient corresponds to microstructural differences, particularly grain size and phase composition, influenced by yttria content. Increased translucency in incisal layers is associated with reduced mechanical performance. These findings emphasize that, despite aesthetic advantages, layer-dependent strength variations must be considered when selecting multilayer zirconia for clinical applications, especially in long-span restorations.

Indexed as

4/5Y-PSZclinical indicationflexural strengthfractographymultilayer zirconiaWeibull statistics

Identifiers

PMID42346691
PMCPMC13302683

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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.