ClinicalTrials.gg
Status unknownNCT04914962zlsUpdated Jun 7, 2021

Wear of Enamel Antagonist to ZLS Crowns

An interventional study of glazed zirconium lithium silicate and polished zirconium lithium silicate in Wear, Tooth and Wear, Occlusal, sponsored by Cairo University. Status unknown. Open to participants aged 21 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2021-06-07.

Primary conditionTooth AttritionRegistry: Tooth WearReclassifiedWhy we changed it
Registry
Tooth Wear — the first condition term the registry derived for this study.
ClinicalTrials.gg
Tooth Attrition
Why
  1. The study's listed conditions name Tooth Attrition, a narrower term within Tooth Wear.
Confidence
High: the new condition is named in the study's own listed conditions. Of 351 hand-checked studies reclassified this way, 68% were exactly right and 84% in the right disease family; the registry's first term was right for 5% (measured 2026-10-21). How we classify →
Wrong?
Tell us the study's main condition →

Sponsored by Cairo University · Not applicable, Interventional, and Treatment

The sponsor has not verified this record recently (last verified Jun 2021), so the status shown — last known as Not yet recruiting — may be out of date.
Phase
Not applicable
Study type
Interventional
Enrollment
26
Allocation
Randomized
Ages
21 Years to 50 Years
Sex
All
01

Study summary

The aim of this study is to evaluate the antagonist enamel wear of two processing options of Celtra duo crowns (polished and glaze fired) restoring posterior teeth in comparison with sound enamel wear at baseline and 6 months

Read the detailed description

Adhesive dental ceramics have proven to guarantee optimal esthetic results alongside satisfactory mechanical properties. Due to these qualities, today they are considered the first-choice restorative materials both for minimal restorations and for the reconstruction of severely compromised teeth. Gold alloy reconstructions preferred in the past, especially for their optimal wear properties, have been progressively substituted by these new materials.

Loss of hard tooth substance is a natural process taking place during mastication. Also, Increased wear is a common reason of failure for restorations exposed to masticatory forces. Excessive wear may be responsible for numerous problems, such as hypersensitivity, loss of occlusal contact, defects of the periodontium, reduction of masticatory efficiency, tooth migration and wrong tooth relations, weakness of masticatory muscles, and changes in the vertical and horizontal jaw relations, which may cause functional and esthetic impairments.

An optimal restorative material should provide similar characteristics to natural dental tissues. The physiological wear of enamel and dentin should represent the reference for a reasonable wear pattern of restorative materials The manufacturers tend to improve the mechanical behavior of their products leads to the progressive offer of new ceramics for daily practice. Assessment of their wear behavior and comparison through detailed tests become necessary at this point.

comparing the wear of enamel opposing polished zirconia, polished lithium disilicate crowns opposing to natural tooth. Patients were recalled after 1year and impression were recorded with opposing arch and baseline and final cast were scanned and superimposed using 3 D scanner. They found that the mean of occlusal wear of the antagonistic enamel of polished zirconia was 42.0 μm, Enamel wear against natural antagonist (control group) 34.68 μm, whereas, for Enamel wear against polished lithium disilicate crowns (group 2) 40.06 μm Enamel wear against natural antagonist (control group) 35.09 μm.

studying the quality of CAD/CAM fabricated single tooth restorations (Ten zirconia restorations were compared to 12 metal ceramic and 10 lithium disilicate counterparts). They found that were no significant differences between the studied crown systems. No difference of the gingival response among the different crown systems. Eighty percent of zirconia crowns needed no occlusal adjustment; also it showed the least amount of marginal discrepancy.

02

Conditions studied

  • Wear, Tooth
  • Wear, Occlusal

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Keywords

  • ZLS
  • crowns
  • occlusal wear
  • glass ceramic
  • polished vs glazed
03

In context

Tooth Attrition Reclassified

14 studies on the registry are indexed under Tooth Attrition; 5 are open to participants now.

This study's planned enrollment of 26 is close to the median of 26 across 11 interventional studies indexed under Tooth Attrition.

Browse Tooth Attrition studies →

Lead sponsor

Cairo University is the lead sponsor of 4,941 studies on the registry; 1,458 are open to participants now.

Of its 37 completed or terminated interventional studies of FDA-regulated products, 5 (14%) have results posted.

Compared within Tooth Attrition, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Tooth Wear. The counts are of registry records indexed under each term, refreshed daily. How we classify →

04

Who can participate

Ages eligible
21 Years to 50 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Pt aged 21-60 years old, be able to read and sign the document.
  • Psychologically and physically able to withstand conventional dental procedures.
  • Patients needing posterior full coverage restorations
  • Patients with sound natural antagonists.
  • Have no active periodontal or pulpal diseases
  • Able to attend punctually for preplanned visits and evaluation.

Exclusion criteria

Exclusion Criteria:

  • Patients with poor oral hygiene, high caries risk and uncooperative patients.
  • Pregnant women.
  • Psychiatric problems or unrealistic expectations.
  • Lack of opposing dentition in the area of interest.
  • Restored occlusal surface opposing the planned restoration.
  • The presence of a removable or fixed orthodontic appliance.
  • Patients with parafunctional habits.
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Outcomes assessor)
Enrollment
26 participants (estimated)

Study arms

  • Active comparator
    monolithic glazedcrowns

    glazed Celtra due crowns

    Other: glazed zirconium lithium silicate

  • Experimental
    monolithic polished crowns

    polished Celtra due crowns

    Other: polished zirconium lithium silicate

Interventions

  • Otherglazed zirconium lithium silicate

    monolithic glazed crown

    Also known as: glazed Celtra due

  • Otherpolished zirconium lithium silicate

    monolithic polishedcrowns

    Also known as: polished Celtra due

06

What researchers measure

Primary outcomes

  1. antagonist enamel wear

    Intraoral digital scanner and superimposition software Mm3 intraoral scanning of enamel antagonist to determine amount of wear in Mm3

    Time frame: 6 months

07

Study locations

No study locations are listed for this record.

08

References and documents

Publications

  • De Angelis F, D'Arcangelo C, Maliskova N, Vanini L, Vadini M. Wear Properties of Different Additive Restorative Materials Used for Onlay/Overlay Posterior Restorations. Oper Dent. 2020 May/Jun;45(3):E156-E166. doi: 10.2341/19-115-L. Epub 2020 Feb 13. PubMed 32053459 ↗
  • Mehta SB, Banerji S, Millar BJ, Suarez-Feito JM. Current concepts on the management of tooth wear: part 1. Assessment, treatment planning and strategies for the prevention and the passive management of tooth wear. Br Dent J. 2012 Jan 13;212(1):17-27. doi: 10.1038/sj.bdj.2011.1099. PubMed 22240686 ↗
  • Dahl BL, Carlsson GE, Ekfeldt A. Occlusal wear of teeth and restorative materials. A review of classification, etiology, mechanisms of wear, and some aspects of restorative procedures. Acta Odontol Scand. 1993 Oct;51(5):299-311. doi: 10.3109/00016359309040581. PubMed 8279271 ↗
  • Nazirkar GS, Patil SV, Shelke PP, Mahagaonkar P. Comparative evaluation of natural enamel wear against polished yitrium tetragonal zirconia and polished lithium disilicate - An in vivo study. J Indian Prosthodont Soc. 2020 Jan-Mar;20(1):83-89. doi: 10.4103/jips.jips_218_19. Epub 2020 Jan 27. PubMed 32089603 ↗
  • Batson ER, Cooper LF, Duqum I, Mendonca G. Clinical outcomes of three different crown systems with CAD/CAM technology. J Prosthet Dent. 2014 Oct;112(4):770-7. doi: 10.1016/j.prosdent.2014.05.002. Epub 2014 Jun 28. PubMed 24980739 ↗
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jun 7, 2021, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04914962
Lead sponsor
Cairo University
Responsible party
Ibrahim Sameh Rady (PhD candidate, Cairo University) — Principal investigator
First posted
Jun 7, 2021
Start date
Jul 10, 2021 (estimated)
Primary completion
Jan 1, 2022 (estimated)
Completion
Jul 1, 2022 (estimated)
Last update
Jun 7, 2021

Study contacts

Ibrahim S Rady, Master
Contact
ibrahim.rady@dentistry.cu.edu.eg
0201099576840
Eman M Anwer, professor
principal investigator · professor of fixed prosthodontics
karim Abo Bakr Mohamed, PhD
study director · teacher of fixed prosthodontics

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

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