Tooth DefectNCT07282977
Efficacy of Three Gingival Displacement Methods
A study testing gingival retraction cord, gingival retraction paste and gingival retraction cord+hemostatic gel in people with Tooth Defect and Teeth Restoration, run by Henan Provincial People's Hospital at 1 site in China.
Trial summary
The goal of this clinical trial is to find the best gingival displacement method for taking impressions of artificial full crowns with subgingival margins. The main question it aims to answer is: Which of the three common gingival displacement methods works best? Researchers will compare three methods: gingival… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Tooth Defect, Teeth Restoration
- What is being tested?
- gingival retraction cord, gingival retraction paste and gingival retraction cord+hemostatic gel
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 39 participants
- Where
- 1 siteChina
- Study dates
- Dec 2025to 30 Jun 2026
- Phase
- Interventional
- 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
Who may be able to join
- need for single crown restoration of maxillary anterior teeth, healthy periodontal status, and subgingival preparation margins on the buccal surface of the affected teeth.
Who cannot join
- requirement for more than one restoration, restoration in other dental quadrants, and supragingival preparation margins.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site
department of stomatology, Henan provincial people's hospital, People's hospital Henan university.
Zhengzhou, Henan, 450000
About this study
Official title: Efficacy of Three Gingival Displacement Methods: A Randomized Clinical Trial
The goal of this clinical trial is to find the best gingival displacement method for taking impressions of artificial full crowns with subgingival margins. The main question it aims to answer is:
Which of the three common gingival displacement methods works best? Researchers will compare three methods: gingival retraction cord, gingival retraction paste, and gingival retraction cord + hemostatic gel, to see which is optimal.
Participants will:
Receive one of the three gingival displacement treatments during impression taking.
Fill out a VAS form to rate their pain.
Read the detailed description
The success and longevity of dental protheses largely depends on the health of periodontium. To fabricate restorations with well-adapted margins, accurate impressions are imperative. Nevertheless, obtaining accurate impressions is challenging when preparations have intentionally placed cervical margins in the gingival sulcus for esthetic or functional purposes. In such cases, gingival displacement is required to ensure that impression materials can penetrate the gingival sulcus and capture the fine details of the prepared abutment margins.
Gingival displacement is the process in which the marginal gingiva is temporarily deflected by external force, and the sulcus opens to facilitate the entry of impression materials. Its objective should be to facilitate obtaining an accurate impression of the tooth preparation without damaging the periodontium. Gingival displacement techniques can be classified into mechanical, chemical, and surgical categories, or into non-surgical and surgical categories. Non-surgical methods can be alternatively classified into retraction cord methods and non-cord methods.
Traditionally, retraction cords have been widely utilized for gingival displacement. However, the retraction cord technique is associated with several drawbacks. First, the pressure exerted by retraction cords can reach up to 5000 kPa, a magnitude that exceeds the recovery capacity of the epithelial attachment, which consequently impairs the integrity of the epithelial attachment. Second, the applied mechanical force may induce bleeding and soft tissue trauma, which can potentially result in subsequent gingival recession. Third, patients frequently report significant levels of discomfort or pain during the procedure. Despite these limitations, cord methods remain the most widely used technique in clinical settings today. Moreover, to address bleeding and crevicular fluid seepage, impregnated retraction cords containing hemostatic agents, vasoconstrictors, or astringents have been introduced into clinical practice.
On the other hand, non-cord methods and materials are gaining increasing acceptance among dental practitioners, with retraction paste being a prominent example. Retraction paste has attracted considerable attention due to its distinct advantages: ease of application, shorter operation time, reduced patient discomfort, no requirement for anesthesia, facilitation of a dry operating field, and minimized tissue trauma compared to retraction cords. Unfortunately, cordless methods also have inherent limitations, such as insufficient gingival sulcus exposure.
Numerous researchers have investigated various gingival displacement methods and materials to assess their efficacy and safety. Unfortunately, study results have been inconsistent or even contradictory, and no consensus has been reached regarding the most appropriate gingival displacement methods and materials. Existing evidence demonstrates that current displacement methods fail to meet clinical requirements, which has prompted the development of new materials, and medications for this purpose. To date, no satisfactory solutions have been identified. Furthermore, high-quality randomized clinical trials (RCTs) focusing on gingival displacement remain limited. The objective of this randomized controlled clinical trial (RCT) is to evaluate the efficacy of three gingival displacement methods. The null hypothesis was that the three methods would yield equivalent displacement effects.
In the present study the enrolled Patients will get different gingival displacement treatment and fill out the VAS form. The objective of the RCT study is to see which method is optimal for gingival displacement.
- Conditions
- Tooth Defect, Teeth Restoration
- Being tested
- gingival retraction cord, gingival retraction paste, gingival retraction cord+hemostatic gel
- Keywords
- gingival displacement, gingival retraction, gingival retraction cord, gingival retraction paste, hemostatic gel
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
gingival retraction cordProcedure or surgery
After tooth preparation, the prepared abutment tooth was rinsed and dried. A preliminary impression was taken using heavy-body silicone. An appropriately sized retraction cord (Ultrapak, #000-#0) was selected and gently packed into the gingival sulcus of the prepared tooth using a cord packer. The cord was left in the gingival sulcus for 7-8 minutes. Following cord removal, light-body silicone was immediately injected around the gingival sulcus of the prepared abutment tooth and into the preliminary impression tray, followed by seating of the preliminary impression tray to obtain the final impression.
gingival retraction pasteProcedure or surgery
After tooth preparation, the prepared abutment tooth was rinsed and dried. A preliminary impression was taken using heavy-body silicone. Retraction paste was injected into the gingival sulcus surrounding the prepared abutment tooth. The retraction paste was left in place for 2 minutes per the manufacturer's instructions, then thoroughly rinsed, and the prepared abutment tooth was air-dried. Light-body silicone was immediately injected around the gingival sulcus and into the preliminary impression tray, followed by seating of the preliminary impression tray to obtain the final impression.
gingival retraction cord+hemostatic gelProcedure or surgery
Appropriately sized retraction cords (Ultrapak, sizes #000-#0) were pre-soaked in hemostatic gel prior to use. After tooth preparation, the prepared abutment tooth was rinsed and dried. A preliminary impression was taken using heavy-body silicone. The gel-soaked retraction cords were gently packed into the gingival sulcus using a cord packer. After 7-8 minutes, the cords were removed, followed by rinsing and drying of the prepared abutment tooth. Light-body silicone was immediately injected around the gingival sulcus and into the preliminary impression tray, followed by seating of the preliminary impression tray to obtain the final impression.
| Study group | Role | What they receive |
|---|---|---|
| gingival retration cord | Experimental | give the patients in this group the gingival displacemet treatment with retraction cord Receives: Procedure: gingival retraction cord |
| gingival retraction paste | Experimental | give the patients in this group the gingival displacemet treatment with retraction paste Receives: Procedure: gingival retraction paste |
| gingival retration cord+ hemostatic gel | Experimental | give the patients in this group the gingival displacemet treatment with retraction cord impregnated with hemostatic gel Receives: Procedure: gingival retraction cord+hemostatic gel |
What is being measured
The primary outcome is the main question the study is designed to answer.
horizontal sulcus width of gingival displacement
After tooth preparation, gingival displacement material was applied to each group and then silicone impressions were taken using the two-step impression technique, and die stone models were poured.The horizontal displacement width of the sulcus was measured on the cast, defined as the linear distance between the margin of the prepared tooth and the adjacent gingival replica on the cast. The mearsurement procedure was carried out with an optical microscope.
Measured: baseline
Secondary outcomes (2)
gingival sulcus bleeding
After the removal of gingival displacement materials, there will be gingival sulcus bleeding in some patients whereas not in other patients. In the present study, this outcome will be classified into two types: bleeding present and no bleeding present according to the bleeding status of the prepared tooth.
Measured: baseline
patient- reported pain
Immediately after gingival displacement and impression taking, patients were asked to complete a Visual Analogue Scale (VAS) to assess their pain level during the gingival displacement procedure. The VAS scale was anchored by "no pain" (0 point) and "unbearable pain" (10 point). Patients completed the VAS independently without interference from the investigators. The scoring criteria were defined as follows: no pain to mild pain: ≤ 3 points; moderate pain (tolerable): 4-6 points; severe pain (intolerable): 7-10 points.
Measured: baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Dec 2025
- Study startDec 2025 (estimated)
- Primary completion30 Jun 2026 (estimated)
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Tooth DefectStudies 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
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 39 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Henan Provincial People's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07282977
- Sponsor's protocol ID
- HenanPPH
- Status last verified
- Dec 2025
- First submitted
- 24 Nov 2025
- Last updated
- 15 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy of Three Gingival Displacement Methods: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT07282977
- Acronym / sponsor ID
- HenanPPH
- Conditions
- Tooth Defect, Teeth Restoration
- Keywords
- gingival displacement, gingival retraction, gingival retraction cord, gingival retraction paste, hemostatic gel
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 39 participants (estimated)
- Lead sponsor
- Henan Provincial People's HospitalUniversity, hospital or other
- Study start
- Dec 2025 (estimated)
- Primary completion
- 30 Jun 2026 (estimated)
- Study completion
- 30 Jun 2026 (estimated)
- First posted
- 15 Dec 2025 (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 find the best gingival displacement method for taking impressions of artificial full crowns with subgingival margins. The main question it aims to answer is:
Which of the three common gingival displacement methods works best? Researchers will compare three methods: gingival retraction cord, gingival retraction paste, and gingival retraction cord + hemostatic gel, to see which is optimal.
Participants will:
Receive one of the three gingival displacement treatments during impression taking.
Fill out a VAS form to rate their pain.
Detailed description
The success and longevity of dental protheses largely depends on the health of periodontium. To fabricate restorations with well-adapted margins, accurate impressions are imperative. Nevertheless, obtaining accurate impressions is challenging when preparations have intentionally placed cervical margins in the gingival sulcus for esthetic or functional purposes. In such cases, gingival displacement is required to ensure that impression materials can penetrate the gingival sulcus and capture the fine details of the prepared abutment margins.
Gingival displacement is the process in which the marginal gingiva is temporarily deflected by external force, and the sulcus opens to facilitate the entry of impression materials. Its objective should be to facilitate obtaining an accurate impression of the tooth preparation without damaging the periodontium. Gingival displacement techniques can be classified into mechanical, chemical, and surgical categories, or into non-surgical and surgical categories. Non-surgical methods can be alternatively classified into retraction cord methods and non-cord methods.
Traditionally, retraction cords have been widely utilized for gingival displacement. However, the retraction cord technique is associated with several drawbacks. First, the pressure exerted by retraction cords can reach up to 5000 kPa, a magnitude that exceeds the recovery capacity of the epithelial attachment, which consequently impairs the integrity of the epithelial attachment. Second, the applied mechanical force may induce bleeding and soft tissue trauma, which can potentially result in subsequent gingival recession. Third, patients frequently report significant levels of discomfort or pain during the procedure. Despite these limitations, cord methods remain the most widely used technique in clinical settings today. Moreover, to address bleeding and crevicular fluid seepage, impregnated retraction cords containing hemostatic agents, vasoconstrictors, or astringents have been introduced into clinical practice.
On the other hand, non-cord methods and materials are gaining increasing acceptance among dental practitioners, with retraction paste being a prominent example. Retraction paste has attracted considerable attention due to its distinct advantages: ease of application, shorter operation time, reduced patient discomfort, no requirement for anesthesia, facilitation of a dry operating field, and minimized tissue trauma compared to retraction cords. Unfortunately, cordless methods also have inherent limitations, such as insufficient gingival sulcus exposure.
Numerous researchers have investigated various gingival displacement methods and materials to assess their efficacy and safety. Unfortunately, study results have been inconsistent or even contradictory, and no consensus has been reached regarding the most appropriate gingival displacement methods and materials. Existing evidence demonstrates that current displacement methods fail to meet clinical requirements, which has prompted the development of new materials, and medications for this purpose. To date, no satisfactory solutions have been identified. Furthermore, high-quality randomized clinical trials (RCTs) focusing on gingival displacement remain limited. The objective of this randomized controlled clinical trial (RCT) is to evaluate the efficacy of three gingival displacement methods. The null hypothesis was that the three methods would yield equivalent displacement effects.
In the present study the enrolled Patients will get different gingival displacement treatment and fill out the VAS form. The objective of the RCT study is to see which method is optimal for gingival displacement.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| gingival retration cord | Experimental | Procedure: gingival retraction cordgive the patients in this group the gingival displacemet treatment with retraction cord |
| gingival retraction paste | Experimental | Procedure: gingival retraction pastegive the patients in this group the gingival displacemet treatment with retraction paste |
| gingival retration cord+ hemostatic gel | Experimental | Procedure: gingival retraction cord+hemostatic gelgive the patients in this group the gingival displacemet treatment with retraction cord impregnated with hemostatic gel |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- need for single crown restoration of maxillary anterior teeth, healthy periodontal status, and subgingival preparation margins on the buccal surface of the affected teeth.
Key exclusion criteria (1 listed)
- requirement for more than one restoration, restoration in other dental quadrants, and supragingival preparation margins.
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 |
|---|---|---|
| gingival retraction cordAfter tooth preparation, the prepared abutment tooth was rinsed and dried. A preliminary impression was taken using heavy-body silicone. An appropriately sized retraction cord (Ultrapak, #000-#0) was selected and gently packed into the gingival sulcus of the prepared tooth using a cord packer. The cord was left in the gingival sulcus for 7-8 minutes. Following cord removal, light-body silicone was immediately injected around the gingival sulcus of the prepared abutment tooth and into the preliminary impression tray, followed by seating of the preliminary impression tray to obtain the final impression. | Procedure or surgery | gingival retration cord |
| gingival retraction pasteAfter tooth preparation, the prepared abutment tooth was rinsed and dried. A preliminary impression was taken using heavy-body silicone. Retraction paste was injected into the gingival sulcus surrounding the prepared abutment tooth. The retraction paste was left in place for 2 minutes per the manufacturer's instructions, then thoroughly rinsed, and the prepared abutment tooth was air-dried. Light-body silicone was immediately injected around the gingival sulcus and into the preliminary impression tray, followed by seating of the preliminary impression tray to obtain the final impression. | Procedure or surgery | gingival retraction paste |
| gingival retraction cord+hemostatic gelAppropriately sized retraction cords (Ultrapak, sizes #000-#0) were pre-soaked in hemostatic gel prior to use. After tooth preparation, the prepared abutment tooth was rinsed and dried. A preliminary impression was taken using heavy-body silicone. The gel-soaked retraction cords were gently packed into the gingival sulcus using a cord packer. After 7-8 minutes, the cords were removed, followed by rinsing and drying of the prepared abutment tooth. Light-body silicone was immediately injected around the gingival sulcus and into the preliminary impression tray, followed by seating of the preliminary impression tray to obtain the final impression. | Procedure or surgery | gingival retration cord+ hemostatic gel |
Primary outcome
horizontal sulcus width of gingival displacement
Time frame: baseline
After tooth preparation, gingival displacement material was applied to each group and then silicone impressions were taken using the two-step impression technique, and die stone models were poured.The horizontal displacement width of the sulcus was measured on the cast, defined as the linear distance between the margin of the prepared tooth and the adjacent gingival replica on the cast. The mearsurement procedure was carried out with an optical microscope.
2 secondary outcomes
gingival sulcus bleeding
Time frame: baseline
patient- reported pain
Time frame: baseline
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 15 Dec 2025.
- Individual participant dataSharing planned: No
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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.
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?
A study testing gingival retraction cord, gingival retraction paste and gingival retraction cord+hemostatic gel in people with Tooth Defect and Teeth Restoration, run by Henan Provincial People's Hospital 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 1 inclusion and 1 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: enrolling by invitation, as of the sponsor's last update on 15 Dec 2025. 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?
horizontal sulcus width of gingival displacement (time frame: baseline). 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 15 Dec 2025.