Alveolar Bone DeficiencyNCT07893873

Long-Term Stability of Soft and Hard Tissues After Guided Bone Regeneration in the Maxillary Anterior Region

An observational study of Alveolar Bone Deficiency, run by Fuming He at 1 site in China.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Trial summary

This study examines the long-term condition of bone and gum tissues around dental implants in the upper front jaw after guided bone regeneration (GBR), a procedure used to rebuild bone at implant sites. Read more about this study

Who is it for?: Ages 18 years and older
Conditions the study is for: Alveolar Bone Deficiency
What is being tested?: Guided Bone Regeneration
Type of treatment: Pill or oral medicine, Surgery or procedure
How many people: 150 participants
Where: 1 siteChina
Study dates: 25 Jul 2026to Sep 2029
Phase: Observational
Are there results?: Not yet: the study is under way

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 18 years and older
All sexes
No healthy volunteers
Adult, Older adult

Study population: Adults who received guided bone regeneration associated with single-tooth implant treatment in the anterior maxilla at the Dental Hospital of Zhejiang University School of Medicine from January 1, 2015, to before ethics approval. At screening, eligible patients had reached, or were expected to reach during the 3-year study period, the T5 assessment window of 5 years after GBR, allowing a variation of plus or minus 12 months. Participants were identified from existing clinical records. Enrollment has closed, and follow-up data collection is ongoing.

Who may be able to join

Age 18 years or older.
Previous guided bone regeneration associated with single-tooth implant treatment in the anterior maxilla.
A single implant-supported fixed restoration; bridge restorations and multi-unit splinted restorations are not eligible.
Available clinical and radiographic records sufficient for analysis of the primary outcome.
Having reached, or expected to reach within the 3-year study period, the T5 long-term follow-up window, defined as approximately 5 years after GBR with an allowable variation of ±12 months.
Ability to complete intraoral scanning, oral examination, and questionnaires.
Ability to understand the study and provide written informed consent. Participants included only through retrospective data for whom consent cannot be obtained must meet the conditions for a waiver of informed consent approved by the ethics committee.
Stable periodontal condition and considered capable of completing long-term follow-up assessment by the investigator.

Who cannot join

Inability to tolerate an oral examination or intraoral scanning.
Pregnancy or breastfeeding.
Smoking 10 or more cigarettes per day.
Severe systemic disease that may substantially affect bone metabolism or implant outcomes.
Immunodeficiency or HIV infection.
Uncontrolled active periodontitis or local inflammation.

Show all 12Show fewer

Head and neck radiotherapy or chemotherapy within the previous year, or a history of intravenous bisphosphonate use.
Severe bruxism or clenching.
Poor oral hygiene or poor compliance.
Substantial missing information in historical GBR records that prevents determination of the surgical technique, grafting material, or imaging assessment time points.
Bridge restorations, multi-unit splinted restorations, or complex full-arch restorations that prevent independent evaluation of the individual implant.
Any other condition considered unsuitable for inclusion by the investigator.

Trial locations and contacts

1 site in 1 country.

China1 site

The Dental Hospital of Zhejiang University School of Medicine
Hangzhou, Zhejiang

Other trials in China

About this study

Official title: Long-Term Stability of Soft and Hard Tissues After Guided Bone Regeneration in the Maxillary Anterior Region: An Ambidirectional Cohort Study

Researchers review existing dental records and images obtained for clinical care and collect information during long-term follow-up. Enrollment has closed, and follow-up data collection is ongoing. Participants undergo intraoral scanning, oral and periodontal examinations, and questionnaires after providing written informed consent.

The study assesses the volume and thickness of augmented hard tissues, bone levels around implants, and surrounding soft tissues. It also assesses implant and restoration survival, health around implants, complications, and patient-reported outcomes. Researchers will explore factors associated with long-term tissue stability.

This is an observational study. It does not assign or change treatment. Cone-beam computed tomography (CBCT) images are used only when obtained for clinical reasons. No CBCT scan is performed solely for research purposes.

Read the detailed description

This single-center observational study uses an ambidirectional cohort design, combining retrospective review of existing clinical records with prospective collection of long-term follow-up data. The retrospective and prospective components concern the same underlying cohort rather than separate treatment groups.

Participants were identified from existing records of adults who previously received guided bone regeneration (GBR) associated with single-tooth implant treatment in the anterior maxilla. Enrollment has closed, and long-term follow-up data collection is ongoing. Screening, enrollment, and reasons for exclusion are documented.

Historical data include clinical, surgical, restorative, radiographic, and maintenance records. Historical records are accessed and used in accordance with the ethics-approved consent and data-use arrangements.

The long-term follow-up assessment is designated T5. Prospective assessments include intraoral scanning, oral and periodontal examinations, and questionnaires. Written informed consent is obtained before prospective research assessments.

CBCT data are used only when obtained for clinical reasons. The treating clinician independently determines any clinical indication for CBCT at follow-up. Participants without a clinical indication do not undergo CBCT solely to provide research measurements. Imaging-based assessments use available clinically obtained datasets.

The study evaluates long-term hard and soft tissue outcomes, implant and restoration survival, peri-implant health, complications, and patient-reported outcomes. Associations between treatment characteristics and long-term tissue stability will be explored.

The patient will be the primary unit of analysis. Where multiple eligible implants from the same patient are included in implant-level analyses, within-patient clustering will be addressed. Treatment characteristics and actual follow-up duration will be recorded and considered in the analyses.

The study does not assign or modify treatment.

Conditions: Alveolar Bone Deficiency
Being tested: Guided Bone Regeneration
Keywords: Guided Bone Regeneration, Dental Implants, Maxillary Anterior Region, Hard Tissue Stability, Soft Tissue Stability, Long-Term Follow-Up, Ambidirectional Cohort Study

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Guided Bone RegenerationProcedure or surgery
Guided bone regeneration was performed as part of previous routine clinical care associated with dental implant treatment in the anterior maxilla. The present observational study does not assign or modify treatment.

Study groups in NCT07893873
Study group	Role	What they receive
Maxillary Anterior GBR Cohort		Adults who previously received guided bone regeneration associated with single-tooth implant treatment in the anterior maxilla. Enrollment has closed, and long-term follow-up data collection is ongoing. Existing clinical records are reviewed, and prospective assessments include intraoral scanning, oral and periodontal examinations, and questionnaires after written informed consent. Receives: Procedure: Guided Bone Regeneration

What is being measured

The primary outcome is the main question the study is designed to answer.

Change in Facial Hard Tissue Thickness at 2 mm Apical to the Implant Shoulder
Facial hard tissue thickness will be measured in millimeters using clinically obtained cone-beam computed tomography (CBCT) images at 2 mm apical to the implant shoulder. The primary outcome is the change in thickness from the postoperative baseline to the long-term follow-up assessment (T5). No CBCT examination will be performed solely for research purposes.
Measured: Postoperative baseline and 5 years after GBR, with an allowable follow-up window of plus or minus 12 months (T5).

Secondary outcomes (11)

Augmented Hard Tissue Volume at Long-Term Follow-Up and Change From Postoperative Baseline
Augmented hard tissue volume will be measured in cubic millimeters using clinically obtained CBCT datasets. The outcomes are the augmented hard tissue volume at the long-term follow-up assessment (T5) and its change from the postoperative baseline. No CBCT examination will be performed solely for research purposes.
Measured: Postoperative baseline and 5 years after GBR, with an allowable follow-up window of plus or minus 12 months (T5).
Facial Hard Tissue Thickness at the Implant Shoulder and 4 mm Apical to the Implant Shoulder at Long-Term Follow-Up
Facial hard tissue thickness will be measured in millimeters using clinically obtained CBCT images at the implant shoulder level (0 mm) and at 4 mm apical to the implant shoulder. Thickness at the long-term follow-up assessment (T5) will be evaluated separately at each measurement level. No CBCT examination will be performed solely for research purposes.
Measured: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Marginal Bone Level at Long-Term Follow-Up
Marginal bone level will be assessed in millimeters using clinically obtained CBCT images at the long-term follow-up assessment (T5). No CBCT examination will be performed solely for research purposes.
Measured: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Facial Soft Tissue Thickness at Long-Term Follow-Up
Facial soft tissue thickness will be assessed in millimeters at the implant shoulder level and 2 mm apical to the implant shoulder by registering T5 intraoral scan data with clinically obtained CBCT data. Values at the two measurement levels will be reported separately. No CBCT examination will be performed solely for research purposes.
Measured: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Facial Soft Tissue Height at Long-Term Follow-Up
Facial soft tissue height will be assessed in millimeters by registering intraoral scan data collected at the long-term follow-up assessment (T5) with clinically obtained CBCT data. No CBCT examination will be performed solely for research purposes.
Measured: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Implant Survival at Long-Term Follow-Up
Implant survival status will be assessed using existing clinical records and the long-term follow-up assessment (T5). Whether each implant remains in place or has been lost or removed will be recorded, together with the date of loss or removal when available.
Measured: From implant placement to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Implant-Supported Restoration Survival at Long-Term Follow-Up
The survival status of the implant-supported restoration will be assessed using existing restorative and follow-up records and the long-term clinical assessment (T5). Whether the original definitive restoration remains in place will be recorded. Documented loss or replacement of the restoration, including the date and reason when available, will also be recorded.
Measured: From definitive restoration placement to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Biological Complications at Long-Term Follow-Up
Biological complications at the implant and guided bone regeneration sites will be assessed using existing clinical and follow-up records and the long-term clinical examination (T5). The presence and type of documented complications will be recorded, together with their timing and management when available.
Measured: From GBR to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Mechanical Complications at Long-Term Follow-Up
Mechanical complications involving the implant-supported restoration and implant components will be assessed using existing clinical, restorative, and follow-up records and the long-term clinical examination (T5). The presence and type of documented complications will be recorded, together with their timing and management when available.
Measured: From implant placement to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Peri-Implant Probing Depth at Long-Term Follow-Up
Peri-implant probing depth will be measured in millimeters during the periodontal examination at the long-term follow-up assessment (T5). Probing depth measurements at the examined sites around each implant will be recorded.
Measured: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Peri-Implant Bleeding on Probing at Long-Term Follow-Up
Bleeding on probing will be assessed during the peri-implant examination at the long-term follow-up assessment (T5). The presence or absence of bleeding following probing will be recorded at each examined site around the implant.
Measured: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

25 Jul 2026Sep 2029

First posted26 Oct 2026
Study start25 Jul 2026
Primary completionSep 2029 (estimated)
Study completionSep 2029 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Other trials for Alveolar Bone DeficiencyStudies 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: Observational
Observational model: Cohort
Time perspective: Other
Enrolment: 150 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT07893873
Sponsor's protocol ID: DHZhejiangU-2026(117)
Status last verified: Oct 2026
First submitted: 18 Oct 2026
Last updated: 26 Oct 2026
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Alveolar Bone Deficiency trials

Study at a glance

From the registry record, last updated by the sponsor on 26 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Long-Term Stability of Soft and Hard Tissues After Guided Bone Regeneration in the Maxillary Anterior Region: An Ambidirectional Cohort Study
ClinicalTrials.gov ID: NCT07893873
Acronym / sponsor ID: DHZhejiangU-2026(117)
Conditions: Alveolar Bone Deficiency
Keywords: Guided Bone Regeneration, Dental Implants, Maxillary Anterior Region, Hard Tissue Stability, Soft Tissue Stability, Long-Term Follow-Up, Ambidirectional Cohort Study
Study type: Observational
Recruitment status: Active, not recruiting
Enrolment: 150 participants (estimated)
Lead sponsor: Fuming HeUniversity, hospital or other
Study start: 25 Jul 2026 (actual)
Primary completion: Sep 2029 (estimated)
Study completion: Sep 2029 (estimated)
First posted: 26 Oct 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.

Detailed description

The study does not assign or modify treatment.

Study design

Observational model: Cohort
Time perspective: Other
Number of arms: 1

Arm	Type	Receives
Maxillary Anterior GBR Cohort	–	Procedure: Guided Bone RegenerationAdults who previously received guided bone regeneration associated with single-tooth implant treatment in the anterior maxilla. Enrollment has closed, and long-term follow-up data collection is ongoing. Existing clinical records are reviewed, and prospective assessments include intraoral scanning, oral and periodontal examinations, and questionnaires after written informed consent.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult
Study population: Adults who received guided bone regeneration associated with single-tooth implant treatment in the anterior maxilla at the Dental Hospital of Zhejiang University School of Medicine from January 1, 2015, to before ethics approval. At screening, eligible patients had reached, or were expected to reach during the 3-year study period, the T5 assessment window of 5 years after GBR, allowing a variation of plus or minus 12 months. Participants were identified from existing clinical records. Enrollment has closed, and follow-up data collection is ongoing.

Key inclusion criteria (8 listed)

Age 18 years or older.
Previous guided bone regeneration associated with single-tooth implant treatment in the anterior maxilla.
A single implant-supported fixed restoration; bridge restorations and multi-unit splinted restorations are not eligible.
Available clinical and radiographic records sufficient for analysis of the primary outcome.
Having reached, or expected to reach within the 3-year study period, the T5 long-term follow-up window, defined as approximately 5 years after GBR with an allowable variation of ±12 months.

Key exclusion criteria (12 listed)

Inability to tolerate an oral examination or intraoral scanning.
Pregnancy or breastfeeding.
Smoking 10 or more cigarettes per day.
Severe systemic disease that may substantially affect bone metabolism or implant outcomes.
Immunodeficiency or HIV infection.

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
Guided Bone RegenerationGuided bone regeneration was performed as part of previous routine clinical care associated with dental implant treatment in the anterior maxilla. The present observational study does not assign or modify treatment.	Procedure or surgery	Maxillary Anterior GBR Cohort

Primary outcome

Change in Facial Hard Tissue Thickness at 2 mm Apical to the Implant Shoulder
Time frame: Postoperative baseline and 5 years after GBR, with an allowable follow-up window of plus or minus 12 months (T5).
Facial hard tissue thickness will be measured in millimeters using clinically obtained cone-beam computed tomography (CBCT) images at 2 mm apical to the implant shoulder. The primary outcome is the change in thickness from the postoperative baseline to the long-term follow-up assessment (T5). No CBCT examination will be performed solely for research purposes.

11 secondary outcomes

Augmented Hard Tissue Volume at Long-Term Follow-Up and Change From Postoperative Baseline
Time frame: Postoperative baseline and 5 years after GBR, with an allowable follow-up window of plus or minus 12 months (T5).
Facial Hard Tissue Thickness at the Implant Shoulder and 4 mm Apical to the Implant Shoulder at Long-Term Follow-Up
Time frame: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Marginal Bone Level at Long-Term Follow-Up
Time frame: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Facial Soft Tissue Thickness at Long-Term Follow-Up
Time frame: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Facial Soft Tissue Height at Long-Term Follow-Up
Time frame: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Implant Survival at Long-Term Follow-Up
Time frame: From implant placement to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Implant-Supported Restoration Survival at Long-Term Follow-Up
Time frame: From definitive restoration placement to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Biological Complications at Long-Term Follow-Up
Time frame: From GBR to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Mechanical Complications at Long-Term Follow-Up
Time frame: From implant placement to the long-term assessment at 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Peri-Implant Probing Depth at Long-Term Follow-Up
Time frame: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).
Peri-Implant Bleeding on Probing at Long-Term Follow-Up
Time frame: At 5 years after GBR, with an allowable window of plus or minus 12 months (T5).

Results and safety

This study is still under way. Results are not available in the source record yet.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 26 Oct 2026.
Individual participant dataSharing planned: No

Related trials for Alveolar Bone Deficiency

Not yet recruiting
Autogenous and Xenograft Bone Mix in Alveolar Ridge Reconstruction
Horizontal Alveolar Ridge Deficiency
Not yet recruiting
Comparison of Three Autogenous Bone and Xenograft Ratios for Horizontal Ridge Augmentation
Horizontal Alveolar Ridge Deficiency
Not yet recruiting
Comparison of Two Autogenous Bone and Xenograft Ratios for Horizontal Ridge Augmentation
Horizontal Alveolar Ridge Deficiency
Not yet recruiting
Shell Technique for Implant Site Development
Ridge Augmentation, Ridge Deficiency
Recruiting
Histological and Histomorphometric Assessment With Inflammatory Profile Analysis of Bone Tissue After Horizontal Ridge Augmentation Using Customized Porous Zirconia Shell
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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.

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

An observational study of Alveolar Bone Deficiency, run by Fuming He at 1 site in China.

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 8 inclusion and 12 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: under way, not looking for participants, as of the sponsor's last update on 26 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.

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?

This study is still under way. Results are not available in the source record yet.

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?

Change in Facial Hard Tissue Thickness at 2 mm Apical to the Implant Shoulder (time frame: Postoperative baseline and 5 years after GBR, with an allowable follow-up window of plus or minus 12 months (T5).). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07893873.

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 26 Oct 2026.