Evaluation of Mandibular Posterior Zirconia Crowns With Different Ti-Base Surface Treatments. (RCT)

March 6, 2026 updated by: MohamedTarek Abdeltawab Salam, October University for Modern Sciences and Arts

Clinical Evaluation of Mandibular Posterior Screw-retained Zirconia Crown With Various Ti-Base Abutment Surface Treatments: Randomized Controlled Clinical Trial

This clinical trial evaluates how different surface treatments on a metal base (Ti-Base) affect the success of dental crowns on implants. Patients receiving a zirconia crown for a missing lower back tooth are divided into three groups: one group receives no special treatment on the metal base, one group receives a silica coating, and the third receives both a silica coating and a chemical primer. The study monitors these crowns for one year to see which treatment best prevents the crown from coming loose or breaking, while also checking the health of the surrounding gums.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a three-arm, parallel-group, superiority randomized controlled trial. The research question addresses the impact of silica coating (CoJet Sand) and primer (Z-Prime Plus) on the survival of mandibular posterior screw-retained zirconia crowns.+3The primary intervention involves treating the titanium base (Ti-Base) abutment surface using 30-mm $SiO_2-Al_2O_3$ particles at 2.0 bar pressure. The three groups are:Group I (Control): No surface treatment.Group II: Tribochemical silica coating alone.Group III: Tribochemical silica coating followed by Z-Prime Plus application.Survival is evaluated using modified United States Public Health Service (USPHS) criteria at baseline, 6 months, and 12 months. Biological health is assessed via the modified plaque index (mPI) and modified Sulcus Bleeding Index (mSBI).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
27

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Egypt
    • Giza Governorate
      • Giza, Giza Governorate, Egypt, 14512
        • MSA University, Faculty of Dentistry

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age 18 - 55 years
  • Missing mandibular first molar with opposing natural teeth
  • Good oral hygiene and general health (ASA I or II)
  • Smoking ≤ 10 cigarettes/day

Exclusion Criteria:

  • Poor oral hygiene
  • Severe wear facets, clenching, or bruxism
  • Heavy smokers (>10 cigarettes/day)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
No Intervention: Control Group (Group I)
Patients in this group receive a screw-retained zirconia crown on a titanium base (Ti-Base) abutment that has received no surface treatment.
Experimental: Intervention Group II
The surface of the titanium base abutment is treated with tribochemical silica coating using 30-μm $SiO_2-Al_2O_3$ particles (CoJet Sand) at 2.0 bar pressure before the zirconia crown is attached.
Device: Tribochemical silica coating.
Surface treatment of titanium base implant abutment using 30 um SiO2 - Al2O3 particles at 2.0 bar pressure.
Other Names:
  • CoJet Sand.
Experimental: Intervention Group III
The titanium base abutment surface is treated with tribochemical silica coating (30-μm $SiO_2-Al_2O_3$ particles at 2.0 bar pressure) followed by the application of a chemical primer (Z-Prime Plus).
Device: Tribochemical silica coating and Z-Prime Plus.
Surface treatment of titanium base implant abutment using 30 um SiO2 - Al2O3 particles at 2.0 bar pressure, followed by the application of Z-Prime Plus primer.
Other Names:
  • CoJet Sand and Z-Prime Plus.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Survival of screw-retained zirconia crown restorations.
Time Frame: Baseline (1 week post-cementation), 6 months, and 12 months.
Evaluation of the restoration using modified United States Public Health Service (USPHS) criteria, specifically assessing fracture behavior, decementation, anatomical form, and marginal adaptation.
Baseline (1 week post-cementation), 6 months, and 12 months.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Modified Plaque Index (mPI)
Time Frame: 12 months.
Evaluation of peri-implant health using the modified Plaque Index, scored from 0 to 3.
12 months.
Modified Sulcus Bleeding Index (mSBI)
Time Frame: 12 months
Evaluation of peri-implant health using the modified Sulcus Bleeding Index, scored from 0 to 3.
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
October University for Modern Sciences and Arts

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Dina Elawady, PhD / Asst. Prof., MSA University, Faculty of Dentistry
  • Study Chair: Hesham Amr, Ph.D, MSA University, Faculty of Dentistry

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 8, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 12, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 12, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 16, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 6, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 9, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 6, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PRO 4.4.1.

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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