Evidence map›Paper›PMID 38734932›Full record

ArticleJournal of prosthodontics : official journal of the American College of Prosthodontists2025

Effect of preparation design and endodontic access on fracture resistance of zirconia overlays in mandibular molars: An in vitro study.

Carlos A Jurado, Kelvin I Afrashtehfar, Manuel Robles, Razan S Alaqeely, Hussain D Alsayed, Terry J Lindquist, Abdulaziz Alhotan

Abstract read
In one paragraph

Article in Journal of prosthodontics : official journal of the American College of Prosthodontists, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
–field-weighted citation impact
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

5 citing papers in PubMed.

  1. Article
  2. Article
  3. Article
  4. Effect of preparation design and endodontic access on fracture resistance of zirconia overlays in mandibular molars: An in vitro study.Journal of prosthodontics : official journal of the American College of Prosthodontists · 2025
    Article
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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

7 authors.

Carlos A JuradoOperative Dentistry Division, Department of General Dentistry, University of Tennessee Health Science Center College of Dentistry, Memphis, Tennessee, USA.ORCID https://orcid.org/0000-0001-7437-4855
Kelvin I AfrashtehfarDepartment of Reconstructive Dentistry and Gerodontology (RekGero), School of Dental Medicine, University of Bern, Bern, Switzerland.ORCID https://orcid.org/0000-0002-6053-8967
Manuel RoblesDepartment of Restorative Dentistry, Universidad del Valle De Mexico, Hermosillo, Sonora, Mexico.ORCID https://orcid.org/0009-0000-0889-6348
Razan S AlaqeelyDepartment of Periodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.ORCID https://orcid.org/0000-0001-6461-4552
Hussain D AlsayedDepartment of Prosthetic Dental Sciences, College of Dentistry, King Saudi University, Riyadh, Saudi Arabia.ORCID https://orcid.org/0000-0002-9566-1981
Terry J LindquistDepartment of Prosthodontics, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, Iowa, USA.ORCID https://orcid.org/0009-0009-4409-9771
Abdulaziz AlhotanDental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.ORCID https://orcid.org/0000-0002-9036-0485

Funding

King Saud University RSPD2024R790
6 · The paper itself

Abstract

purposeTo evaluate the fracture resistance of zirconia overlays, considering various preparation designs and the presence of endodontic access. MATERIALS AND

methodsNinety translucent zirconia (5Y-PSZ) overlay restorations were divided into six groups (n = 15/group) based on different preparation designs, with and without endodontic access: chamfer margin 4 mm above the gingival level without (group 1) and with endodontic access (group 2); margin 2 mm above the gingival level without (group 3) and with endodontic access (group 4); overlay with no chamfer margin without (group 5) and with endodontic access (group 6). Restorations were bonded to mandibular first molar resin dies, and the groups with endodontic access were sealed with flowable resin composite. All restorations underwent 100,000 cycles of thermal cycling between 5°C and 55°C, followed by loading until fracture. Maximum load and fracture resistance were recorded. ANOVA with Tukey post-hoc tests were used for statistical comparison (α < 0.05).

resultsFracture resistance significantly varied among overlay designs with and without endodontic access (p < 0.001), except for the no-margin overlays (groups 5 and 6). Overlays with a 2 mm margin above the gingival margin with endodontic access (group 4) exhibited significantly higher fracture resistance compared to both the 4-mm supragingival (group 2) and no-margin (group 6) designs, even when compared to their respective intact groups (groups 1 and 5). There were no significant differences between the no-margin and 4-mm supragingival overlays.

conclusionThe more extensive zirconia overlay for mandibular molars is the first choice since the 2 mm margin above the gingival level design withstood considerable loads even after undergoing endodontic access. A no-margin overlay is preferred over the 4-mm supragingival design as it preserves more tooth structure and there was no outcome difference, irrespective of endodontic access. Caution is warranted in interpreting these findings due to the in vitro nature of the study.

Indexed as

Dental MaterialsDental Prosthesis DesignMolarZirconiumComposite ResinsDental Restoration FailureDental Restoration, PermanentDental Stress AnalysisHumansIn Vitro TechniquesMandibleMaterials TestingComposite ResinsDental MaterialsZirconiumzirconium oxidedental prosthesis designdental restoration failuredental stress analysisendodontic accessendodontically‐treated teethfinish linefracture resistancefracture toughnessocclusal veneerszirconium oxide

Identifiers

PMID38734932
PMCPMC11976686

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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.