Gingival HealthNCT07500636
Long-Term Periodontal Tissue Changes Associated With Metal-Ceramic Crowns: An 8-Year Split-Mouth Study
A study testing Metal-ceramic crown in people with Gingival Health and Metal-Ceramic Restorations, run by Riga Stradins University.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 20 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Gingival Health, Metal-Ceramic Restorations
- What is being tested?
- Metal-ceramic crown
- Type of treatment
- Pill or oral medicine, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- No sites listed yet
- Study dates
- Oct 2015to Sep 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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).
Who cannot join
- 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.
About this study
Official title: 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.
Read more
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.
Read the 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.
- Conditions
- Gingival Health, Metal-Ceramic Restorations
- Being tested
- Metal-ceramic crown
- Keywords
- metal-ceramic, gingival index, recession, pocket probing depth, gingival health
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Metal-ceramic crownDevice
Also called Gingival pocket depth, Gingival recession, Gingival index
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.
| Study group | Role | What they receive |
|---|---|---|
| Participant with 1 metal-ceramic crown (test)and nonrestored natural tooth in oral cavity (control) | Active comparator | 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). Receives: Device: Metal-ceramic crown |
What is being measured
The primary outcome is the main question the study is designed to answer.
Clinical parameters
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,
- Mild inflammation: slight change in color, slight edema, no bleeding on probing,
- Moderate inflammation: redness, edema, and glazing, or bleeding on probing,
- 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.
Measured: 8 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Mar 2026
- Study startOct 2015
- Primary completionSep 2016
- Study completionSep 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gingival HealthStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Split mouth design to evaluate the effects of metal-ceramic (MC) crowns on periodontal tissues by comparing them with the periodontal tissues of a contralateral tooth in the same oral cavity
- Masking
- None (open label)
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- Riga Stradins University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Elīna Bluma, Riga Stradins University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07500636
- Sponsor's protocol ID
- E-9 (2)
- Status last verified
- Mar 2026
- First submitted
- 23 Mar 2026
- Last updated
- 3 Apr 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-Term Assessment of Periodontal Tissue Health Following Metal-Ceramic Crown Use: Complication Rates and Prevention Strategies
- ClinicalTrials.gov ID
- NCT07500636
- Acronym / sponsor ID
- E-9 (2)
- Conditions
- Gingival Health, Metal-Ceramic Restorations
- Keywords
- metal-ceramic, gingival index, recession, pocket probing depth, gingival health
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 32 participants (actual)
- Lead sponsor
- Riga Stradins UniversityUniversity, hospital or other
- Study start
- Oct 2015 (actual)
- Primary completion
- Sep 2016 (actual)
- Study completion
- Sep 2024 (actual)
- First posted
- 30 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Split mouth design to evaluate the effects of metal-ceramic (MC) crowns on periodontal tissues by comparing them with the periodontal tissues of a contralateral tooth in the same oral cavity
| Arm | Type | Receives |
|---|---|---|
| Participant with 1 metal-ceramic crown (test)and nonrestored natural tooth in oral cavity (control) | Active comparator | Device: Metal-ceramic crownA 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). |
Who may qualify
- Ages
- 20 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 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).
Key exclusion criteria (6 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Metal-ceramic crownAlso: Gingival pocket depth, Gingival recession, Gingival indexThe 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. | Device | Participant with 1 metal-ceramic crown (test)and nonrestored natural tooth in oral cavity (control) |
Primary outcome
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.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Apr 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Metal-ceramic crown in people with Gingival Health and Metal-Ceramic Restorations, run by Riga Stradins University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 3 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Clinical parameters (time frame: 8 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Apr 2026.