Evidence map›Paper›PMID 42568076›Full record

ArticleBMC oral health2026

Retention and wear assessment of novel PolyEtherKetoneKetone versus traditional cobalt chromium material used in digital double crown retained removable partial dentures.

Rania Abd Elsattar Mangood Ramadan, Sawsan Maged Fadl, Shaimaa Mohamed Abu El Sadat Ali, Rami Maher Ghali

Abstract readComparative Study
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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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

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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

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No citing paper in PubMed yet.

4 · The record

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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

4 authors.

Rania Abd Elsattar Mangood RamadanOral and Maxillofacial Prosthodontics Department, Faculty of Dentistry, Ain shams university, Cairo, Egypt. raniamangod@dent.asu.edu.eg.
Sawsan Maged FadlOral and Maxillofacial Prosthodontics Department, Faculty of Dentistry, Ain shams university, Cairo, Egypt.
Shaimaa Mohamed Abu El Sadat AliOral and Maxillofacial Radiology Department, Faculty of Dentistry, Ain shams university, Cairo, Egypt.
Rami Maher GhaliOral and Maxillofacial Prosthodontics Department, Faculty of Dentistry, Ain shams university, Cairo, Egypt.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundConventional removable partial dentures (RPDs) involve a process that is often susceptible to errors and demands a significant investment of time. The introduction of computer-aided design and computer-aided manufacturing (CAD/CAM) technology and materials witnessed significant advancements in recent years to produce accurate removable partial dentures. This study evaluated the retention and wear of PolyEtherKetoneKetone (PEKK) compared to Cobalt-Chromium (CoCr) in digitally fabricated double crown removable partial dentures for lower Kennedy Class I cases.

methodsThe study was performed on 3D digital models of mandibular Kennedy Class I with prepared premolars bilaterally. The double crown RPDs were designed and fabricated digitally to get 14 copies of RPDs. Two groups were defined (n = 7); the first group were milled from Co-Cr discs, and the other's from PEKK blanks. Initial retention was measured using a universal testing machine. RPDs were then subjected to dynamic loading in a chewing simulator over 100,000 cycles followed by 540 manual insertion and removal cycles and were remounted on the testing machine to measure final retention simulating six months. Wear was assessed using Geomagic Control X software, where negative deviations highlighted areas of degradation. Data was collected and analyzed for statistical analysis. Two Sample t-test was used to compare between the two groups and Paired t test to study the changes within each group. The significance level was set at P ≤ 0.05.

resultsPEKK group showed a statistically significantly higher final retentive values after 6 months (11.6 N) than Co-Cr (2 N). Moreover, results showed higher retention loss in Co-Cr group (16.9 N) compared to PEKK (3.7 N). Additionally, wear assessment of primary copings indicated a higher deviation in the Co-Cr group (-0.25 mm) compared to PEKK (-0.096 mm), with a notable correlation (0.651, P-value = 0.011) between retention loss and wear.

conclusionsWithin the limitation of this study, it could be concluded that PEKK provided digitally fabricated double crown RPDs with higher retention values and less wear than Co-Cr after simulation of 6 months of RPD use.

Indexed as

Chromium AlloysCrownsDental MaterialsDental Restoration WearDenture DesignDenture, Partial, RemovableDenture RetentionKetonesPolyethylene GlycolsBenzophenonesComputer-Aided DesignDental Stress AnalysisHumansImaging, Three-DimensionalMaterials TestingPolyether CompoundsBenzophenonesChromium AlloysDental MaterialsKetonesPolyether CompoundspolyetheretherketonepolyetherketoneketonePolyethylene GlycolsPolymersDigitalDouble crownPartial denturesPolyEtherKetoneKetoneRetentionWear

Identifiers

PMID42568076
PMCPMC13452113

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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.