Long-Term Periodontal Tissue Changes Associated With Metal-Ceramic Crowns: An 8-Year Split-Mouth Study

March 30, 2026 updated by: Elīna Bluma, Riga Stradins University

Long-Term Assessment of Periodontal Tissue Health Following Metal-Ceramic Crown Use: Complication Rates and Prevention Strategies

The goal of this clinical trial is to to evaluate the periodontal condition around metal-ceramic crown. The main question to be answered is: whether the metal-ceramic crown is the cause of gum changes? The study offers to involve patients who receive single metal-ceramic crown and have kept the same tooth intact on the other side of the mouth.

The condition of the gums around the crown will be compared with the corresponding natural teeth on the oposite side of the mouth. Clinical parameters such as plaque accumulation, bleeding on probing, periodontal pocket depth and gingival recession will be evaluated. All procedures are part of routine dental examination.

Participants:

will be invited for gingival examination 3 months after receiving the metal-ceramic crown, will receive a routine hygiene instruction, will be invited for gingival re-examination after 8 years.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The aim of this study is to evaluate the effects of metal-ceramic (MC) crowns on periodontal tissues over 8-year period, using a split-mouth design by comparing treated teeth with contralateral teeth within the same oral cavity.

The preparation and manufacturing of the MC crown is performed following a standardized clinical and laboratory protocol. Tooth preparation follow routine requirements, including creation of a chamfer preparation line and placing the crown margin equigingivally.

An initial follow-up examination is performed three months after the placement of the MC crown. The examination is performed by a prosthodontist under a dental operating light, using a flat-surfaced intra-oral mirror and a dental/periodontal probe. Both the restored tooth (test) and the contralateral natural tooth (control) are examined.

Attention is paid to examin the gingival tissue determining the degree of gum inflammation, the amount of plaque around the crown. The depth of the gum pockets are measured and the amount of recession is determined.

Inspection records are made twice, 3 months and 8 years after the placement of MC crowns.

All data are confidential and are used only within the framework of the study. Participation is voluntary. Patient have the option to withdraw their participation in the study at any time. This will not affect further treatment at institution.

If patients have any questions about the study they are invited to contact: call or visit the Clinic of Prosthetic Dentistry/ RSU Institute of Stomatology.

Study Type

Interventional

Enrollment (Actual)

32

Phase

  • Not Applicable

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
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Patients with a tooth-based metal-ceramic crown intended.
  • Patients with a good general state of health, i.e. do not suffer from chronic uncontrolled general illnesses (diabetes, cardiovascular diseases, oncological diseases).
  • Patients who have corresponding natural tooth on opposite side without a fixed dental prosthesis (crown, bridge).

Exclusion Criteria:

  • Pregnancy.
  • With local inflammation and diseases of the oral mucosa.
  • With removable prostheses in both jaws.
  • Smokers (>20 cigarettes per day).
  • With an extraction wound next to an exposed tooth.
  • With neurological or psychiatric problems that affect hygiene.

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Participant with 1 metal-ceramic crown (test)and nonrestored natural tooth in oral cavity (control)
A patient (who visits the department's clinic) with a clinical necessity and his own choice to make a metal-ceramic crown (test group) for incisors, canines, premolars, and molars, but has a non-restored corresponding natural tooth on the opposite side of the mouth (control group).
Device: Metal-ceramic crown

The preparation and manufacturing of the MC crown was performed following a standardized clinical and laboratory protocol. Final impression was taken with a one-step technique in a standard tray. All crowns were manufactured in the same dental laboratory. The metal frameworks were fabricated in cobalt-chromium using the lost-wax technique and then veneered with ceramic using a layering technique. All restorations were cemented with zinc phosphate cement.

The examination was performed under a dental operating light, using a flat-surfaced intra-oral mirror and a dental/periodontal probe. Both the restored tooth (test) and the contralateral natural tooth (control) were examined. Records were made for the gingival condition using the Silness & Loe gingival index. Gingival pocket depth measured in millimeters, gingival recession was measured as distance in millimeters (mm) from the cementoenamel junction to the gingival margin.

Other Names:
  • Gingival index
  • Gingival pocket depth
  • Gingival recession

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical parameters
Time Frame: 8 years

Records were made for the gingival condition of test and control using the Silness & Loe gingival index, scoring four sites (M, D, B, L) for each tooth. The mean value for each tooth was then calculated.

Gingival index (GI) according to Silness & Loe. Scores Description 0-Normal gingiva,

  1. Mild inflammation: slight change in color, slight edema, no bleeding on probing,
  2. Moderate inflammation: redness, edema, and glazing, or bleeding on probing,
  3. Severe inflammation: marked redness and edema, tendency toward spontaneous bleeding.

Gingival pocket depth measured in millimeters was assessed at 6 surfaces per tooth by inserting a dental probe between teeth and gumline and recording the distance from the gingival margin to the base of the pocket, with the deepest measurement considered. Gingival recession was measured as distance in millimeters (mm) from the cementoenamel junction to the gingival margin, with the greatest value recorded.
8 years

Collaborators and Investigators

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

Sponsor

Riga Stradins University

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)

October 1, 2015

Primary Completion (Actual)

September 1, 2016

Study Completion (Actual)

September 1, 2024

Study Registration Dates

First Submitted

March 23, 2026

First Submitted That Met QC Criteria

March 23, 2026

First Posted (Actual)

March 30, 2026

Study Record Updates

Last Update Posted (Actual)

April 3, 2026

Last Update Submitted That Met QC Criteria

March 30, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • E-9 (2)

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.

Clinical Trials on Gingival Health

Clinical Trials on Metal-ceramic crown

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in United Arab Emirates

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe