Clinical Evaluation of Different Treatments for Interdental Black Triangles (BT-RCT)

Efficacy of Nonsurgical Versus Surgical Management of Black Triangles: A Randomized Clinical Trial

This randomized clinical trial aims to evaluate and compare the effectiveness of surgical and nonsurgical treatment approaches for the management of interdental black triangles. Black triangles are open gingival embrasures caused by the loss or deficiency of the interdental papilla between adjacent teeth. These spaces are a common esthetic concern and may also contribute to food impaction and periodontal problems.

Thirty adult patients presenting with interdental papillary loss classified as Nordland and Tarnow Class I or II will be recruited from the outpatient clinics of the Faculty of Dentistry at King Salman International University. Eligible participants will be randomly assigned to one of three treatment groups: surgical reconstruction using the tube grafting technique, papillary augmentation using hyaluronic acid injection, or a restorative approach using the injection molding composite technique.

Clinical and photographic assessments will be performed at baseline and during follow-up visits at 3 and 6 months after treatment. The primary outcomes will be the reduction in black triangle surface area and height. Secondary outcomes will include clinical periodontal parameters such as plaque index, bleeding score, probing pocket depth, and clinical attachment level. Patient satisfaction with the esthetic outcome will also be evaluated using a Visual Analog Scale (VAS).

The findings of this study are expected to provide evidence regarding the comparative effectiveness of surgical and nonsurgical approaches for the management of interdental black triangles and help clinicians select the most predictable treatment modality for improving esthetic outcomes.

Study Overview

• Status: Recruiting
• Conditions: Papilla Reconstruction; Black Triangles Syndrome (BTS)
• Intervention / Treatment: Procedure: Tube Grafting Technique for Papilla Reconstruction; Drug: Hyaluronic Acid (HA); Procedure: Injection Molding Composite Technique

Detailed Description

Interdental papilla deficiency resulting in the formation of "black triangles" is a frequent esthetic and functional problem in dentistry. These open gingival embrasures occur due to several factors including periodontal attachment loss, traumatic oral hygiene practices, tooth morphology, orthodontic treatment, and aging. In addition to compromising dental esthetics, black triangles may lead to food impaction, phonetic problems, and patient dissatisfaction with their smile.

Several therapeutic approaches have been proposed for the management of interdental papillary loss. These approaches can generally be classified into surgical and nonsurgical techniques. Surgical methods aim to reconstruct the lost papillary tissue through soft tissue grafting procedures such as the tube grafting technique. These procedures attempt to biologically restore the interdental papilla but may involve surgical morbidity and require advanced clinical skills.

Nonsurgical approaches have recently gained interest as minimally invasive alternatives. One such approach involves the use of injectable fillers such as hyaluronic acid to augment the volume of the interdental papilla. Hyaluronic acid is widely used in aesthetic medicine due to its biocompatibility and ability to promote tissue hydration and volumization. Another nonsurgical strategy is the restorative modification of tooth contours using the injection molding composite technique, which alters the shape of the proximal tooth surfaces to reduce the appearance of the gingival embrasure.

Despite the availability of these different treatment options, there is limited evidence directly comparing surgical and nonsurgical approaches for the management of interdental black triangles. Therefore, the present study aims to evaluate the efficacy of these treatment modalities in a randomized clinical trial design.

Thirty patients presenting with interdental papilla deficiency will be recruited from the outpatient clinic of the Faculty of Dentistry at King Salman International University. Eligible participants will be adults aged 18 to 50 years with Nordland and Tarnow Class I or II papillary loss and adequate interdental bone support (≤5 mm distance from the contact point to the alveolar crest). Participants with systemic diseases affecting wound healing, active periodontal disease, periapical pathology, pregnancy or lactation, parafunctional habits, or smoking history will be excluded.

After baseline assessment, participants will be randomly allocated into three equal groups:

Group I: Surgical reconstruction of the interdental papilla using the tube grafting technique.

Group II: Papillary augmentation using hyaluronic acid injection.

Group III: Restorative treatment using the injection molding composite technique.

Baseline clinical examination will include plaque index, bleeding index, probing pocket depth, and clinical attachment level. Standardized intraoral photographs will be obtained using a digital camera under controlled conditions. Image analysis software will be used to measure the surface area and height of the black triangle.

Follow-up assessments will be conducted at 3 months and 6 months after treatment. At each follow-up visit, clinical periodontal parameters and photographic measurements will be repeated. Patient satisfaction with the esthetic outcome will be evaluated using a Visual Analog Scale.

The primary outcomes of this study are the changes in black triangle surface area and height over time. Secondary outcomes include periodontal clinical parameters and patient-reported esthetic satisfaction. The results of this randomized clinical trial are expected to provide clinically relevant evidence regarding the effectiveness and stability of surgical and nonsurgical techniques for the management of interdental black triangles, contributing to evidence-based decision-making in esthetic dental practice.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Fatma E.A. Hassanein, PHD; Phone Number: +201000093885; Email: fatma.hassanein@ksiu.edu.eg
• Study Contact Backup: Name: Fatma E.A. Hassanein, PHD; Phone Number: 01000093885; Email: fatma.hassanein@ksiu.edu.eg

Study Locations

• Egypt
  • Cairo, Egypt
    • Recruiting
    • Faculty of Dentistry, King Salman International University
    • Contact: Fatma E.A. Hassanein, PHD; Phone Number: 01000093885; Email: fatma.hassanein@ksiu.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 to 50 years.

Presence of interdental black triangle classified as Nordland and Tarnow Class I or Class II.

Radiographic evidence of adequate interdental bone support, defined as ≤5 mm distance from the contact point to the alveolar crest.

Systemically healthy individuals with no medical conditions affecting wound healing.

Patients willing to participate in the study and attend follow-up visits at 3 and 6 months.

Exclusion Criteria:

• Patients with systemic diseases that may impair wound healing.

Presence of teeth with acute periapical pathology.

Presence of periodontal pockets or active periodontal disease.

Pregnant or lactating women.

Patients with parafunctional habits (e.g., bruxism).

Smokers, alcoholics, or drug abusers.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Surgical Tube Technique; Participants in this arm will receive surgical reconstruction of the interdental papilla using the tube grafting technique. The procedure involves local anesthesia, preparation of the recipient site, and placement of a connective tissue graft to augment the interdental papilla. The graft will be stabilized to promote papillary regeneration and closure of the black triangle.	Procedure: Tube Grafting Technique for Papilla Reconstruction; A surgical procedure used to reconstruct the interdental papilla for management of black triangles. Under local anesthesia, the recipient papillary area is prepared and a connective tissue graft is harvested and shaped using the tube grafting technique. The graft is inserted into the interdental area and stabilized to increase papillary volume and promote soft-tissue regeneration. The aim is to biologically reconstruct the lost papilla and reduce the gingival embrasure space.; Other Names: Papilla Tube Technique; Interdental Papilla Reconstruction Surgery
Experimental: Hyaluronic Acid Injection; Participants in this arm will receive papillary augmentation using hyaluronic acid gel injection. A controlled volume of cross-linked hyaluronic acid (<0.2 ml) will be injected into the interdental papilla to increase tissue volume and reduce the appearance of the black triangle.	Drug: Hyaluronic Acid (HA); A minimally invasive papillary augmentation procedure using injectable cross-linked hyaluronic acid gel. A controlled volume of hyaluronic acid (<0.2 ml) is injected directly into the interdental papilla using a fine needle to increase tissue volume and improve papillary contour. The treatment aims to reduce the appearance of black triangles by enhancing soft-tissue fullness in the interdental region.; Other Names: Cross-linked Hyaluronic Acid; HA Dermal Filler
Experimental: Injection Molding Restorative Technique; Participants in this arm will receive restorative treatment using the injection molding composite technique. A matrix system will be used to guide composite placement, and heated flowable composite resin will be injected to modify proximal tooth contours and reduce the gingival embrasure space responsible for the black triangle.	Procedure: Injection Molding Composite Technique; A restorative approach used to reduce the appearance of black triangles by modifying proximal tooth contours. A matrix system is used to guide the restoration, and a bonding agent is applied followed by injection of heated flowable composite resin. The composite is shaped to alter the emergence profile and reduce the gingival embrasure space, thereby improving interdental papilla support and esthetics.; Other Names: Bioclear Injection Molding Technique; Composite Injection Technique

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Reduction in Black Triangle Surface Area	The primary outcome will be the quantitative change in the surface area of the interdental black triangle. Measurements will be obtained from standardized intraoral photographs and analyzed using digital image analysis software. Surface area will be calculated in square millimeters (mm²). The outcomes will be compared between treatment groups to evaluate the effectiveness of the interventions in reducing interdental papillary deficiency.	Baseline, 3 months, and 6 months after treatment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plaque Index	Plaque accumulation around the treated teeth will be assessed using a periodontal probe and recorded according to a standardized plaque index scoring system. This measure will be used to evaluate oral hygiene status and its potential influence on treatment outcomes.	Baseline, 3 months, and 6 months after treatment.
Bleeding on Probing	Bleeding on probing will be recorded during periodontal examination to evaluate gingival inflammation around the treated sites. The presence or absence of bleeding after gentle probing will be documented as an indicator of periodontal health.	Baseline, 3 months, and 6 months after treatment.

Collaborators and Investigators

• Sponsor: Ain Shams University
• Investigators: Principal Investigator: Fatma E.A. Fatma E.A., PHD, Assistant Professor Of Oral Medicine, Periodontology, Oral Diagnosis

Study record dates

Study Major Dates

• Study Start (Estimated): April 22, 2026
• Primary Completion (Estimated): September 15, 2026
• Study Completion (Estimated): October 15, 2026

Study Registration Dates

• First Submitted: March 11, 2026
• First Submitted That Met QC Criteria: April 21, 2026
• First Posted (Actual): April 23, 2026

Study Record Updates

• Last Update Posted (Actual): April 23, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Carbohydrates; Glycosaminoglycans; Polysaccharides; Hyaluronic Acid
• Other Study ID Numbers: IRB09

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No