Dimensional Changes in Single Crowns Supported by Short Transmucosal Implants With Diverging or Converging Neck Profiles in the Esthetic Zone

November 14, 2025 updated by: ARDEC Academy

Long-term Dimensional Changes in Single Crowns Supported by Short (6 mm) Transmucosal Implants With Divergent or Convergent Neck Profiles in the Esthetic Zone. A Randomized Randomized Controlled Clinical Trial

The goal of the present randomized clinical trial is to assess the long-term osseous and peri-implant soft tissue changes as well as the success rate of short implants (6 mm) with a converging collar with micro threads or a diverging polished collar placed in the esthetic zone of the maxilla on partially edentulous patients. The main questions it aims to answer are:

  • what are the long-term bone and soft tissue changes around implants with a converging collar with micro threads compared to a diverging polished collar placed in the esthetic zone of the maxilla?
  • What is the success rate of implants with a converging collar with micro threads compared to a diverging polished collar placed in the esthetic zone of the maxilla? Dental implants with a converging collar with micro threads or a diverging polished collar will be placed in the esthetic zone of the maxilla of the included participants and the measurements regarding the bone and soft tissue level will be compared.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

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

The objectives of the present randomized clinical trial are to evaluate the clinical and radiographic changes over time of hard and soft tissues around implants with a convergent or divergent collar. Twenty volunteer participants with two edentulous regions in the maxillary esthetic zone (from the right second premolar to the left second premolar) will be included in the study. Two implants will be randomly installed, one with a convergent collar and one with a divergent collar. After 3 months of healing, individual crowns will be installed. At each visit the following parameters will be evaluated: plaque index, probing depth, bleeding on probing, the recession of the mucosal margin, intraoral radiographs, likewise control CBCT, and impressions will be performed. The visit will take place at 6 and 12 months and then annually for a minimum of 3 years. Changes at the level of the marginal bone will be assessed overtime on the radiographs. Dimensional changes will be clinically evaluated during control evaluations and later through digital impressions.

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 (Estimated)

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.
20

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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Peru
    • La Libertad
      • Trujillo, La Libertad, Peru, 13001
        • Universidad Nacional de Trujillo

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:

  • Presence of at least two edentulous areas in the esthetic region of the maxilla (from right to left from second premolar to premolar, preferably first premolars and incisors)
  • Alveolar bone ≥ 8 mm in height and ≥ 5 mm in thickness assessed on CBCT.
  • Age of ≥ 21 years.
  • Need for an implant-supported prosthetic restoration.
  • Be in good general health with no contraindications to oral surgical procedures.
  • Not be pregnant.
  • Patients who agree to participate in the study and sign the informed consent.

Exclusion Criteria:

  • The presence of any uncontrolled systemic disease.
  • History of past or ongoing chemotherapeutic or radiotherapeutic treatments.
  • Heavy smokers (>10 cigarettes per day).
  • Previous bone regeneration procedures in the area of interest

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: Quadruple

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.
Experimental: dental implant with a convergent collar
One implant with a converging collar with micro threads will be installed in each patient according to the site randomization in the esthetic region of the upper jaw (between the second premolars).
Procedure: Dental implants placement
surgery for placement of two one-piece trans gingival implants
Other Names:
  • implant supported prosthetic restoration
Active Comparator: dental implant with a divergent collar
One implant with a diverging polished collar will be installed in each patient according to the site randomization in the esthetic region of the upper jaw ( between the second premolars).
Procedure: Dental implants placement
surgery for placement of two one-piece trans gingival implants
Other Names:
  • implant supported prosthetic restoration

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
height of the periimplant bone tissues
Time Frame: baseline
The height of the periimplant bone tissues will be evaluated in the intraoral radiographic images, cone beam tomography, and the three-dimensional images obtained from the digital prints
baseline
height of the periimplant bone tissues
Time Frame: 3 years follow up
The height of the periimplant bone tissues will be evaluated in the intraoral radiographic images, cone beam tomography, and the three-dimensional images obtained from the digital prints
3 years follow up
height of the periimplant soft tissues
Time Frame: Baseline
The height of the periimplant soft tissues will be evaluated in the intraoral radiographic images, cone beam tomography, and the three-dimensional images obtained from the digital prints
Baseline
height of the periimplant soft tissues
Time Frame: 3 years follow up
The height of the periimplant soft tissues will be evaluated in the intraoral radiographic images, cone beam tomography, and the three-dimensional images obtained from the digital prints
3 years follow up

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
Plaque index
Time Frame: 1 year
to score the plaque accumulation of plaque around implants will be used the Mombelli et al index
1 year
Plaque index
Time Frame: 3 year
to score the plaque accumulation of plaque around implants will be used the Mombelli et al index
3 year
Bleeding on probing
Time Frame: 1 year
During the probing, the bleeding on probing will be registered in the periodontal record.
1 year
Bleeding on probing
Time Frame: 3 year
During the probing, the bleeding on probing will be registered in the periodontal record.
3 year
Probing depth
Time Frame: 1 year
A calibrated probe will be used to measure the probing depth in all teeth annually.
1 year
Probing depth
Time Frame: 3 year
A calibrated probe will be used to measure the probing depth in all teeth annually.
3 year
Implant success rate
Time Frame: 1 year
The criteria to evaluate the success rate will be if there was no persistent and/or irreversible signs or symptoms such as pain, infection, neuropathies, or paresthesia, no peri-implant infection with suppuration, no mobility, and no continuous radiolucency around the implant.
1 year
Implant success rate
Time Frame: 3 years
The criteria to evaluate the success rate will be if there was no persistent and/or irreversible signs or symptoms such as pain, infection, neuropathies, or paresthesia, no peri-implant infection with suppuration, no mobility, and no continuous radiolucency around the implant.
3 years

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.
ARDEC Academy

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Universidad Nacional de Trujillo

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.
April 1, 2023

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.
September 30, 2025

Study Completion (Estimated)

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.
December 30, 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).
April 5, 2023

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.
August 18, 2023

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.
August 23, 2023

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.
November 17, 2025

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.
November 14, 2025

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.
November 1, 2025

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.
  • UNT_short implants

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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