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

Completed

Conditions

Intervention / Treatment

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

Interventional

Enrollment (Actual)

27

Phase

  • 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

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
Intervention / Treatment
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

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

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

October University for Modern Sciences and Arts

Investigators

  • 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)

January 8, 2025

Primary Completion (Actual)

January 12, 2026

Study Completion (Actual)

February 12, 2026

Study Registration Dates

First Submitted

February 16, 2026

First Submitted That Met QC Criteria

March 6, 2026

First Posted (Actual)

March 9, 2026

Study Record Updates

Last Update Posted (Actual)

March 9, 2026

Last Update Submitted That Met QC Criteria

March 6, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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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