2026-09-26
Black triangles and diastemas: how to close them with the Bioclear Method
With the Bioclear Method, black triangles (open interproximal spaces below the contact point) and diastemas are closed directly and additively: a clear anatomic matrix is seated into the gingival sulcus, heated composite is injected into it and the restoration is cured through the matrix. Because the matrix already has the tooth contour and emergence profile, the composite is shaped smoothly, without overhangs at the gingiva and without manual layering lines. IMMT is the official representative of Bioclear and helps clinics choose and order the right kit.
Why black triangles and diastemas are challenging
A black triangle appears when the interdental papilla does not fill the space between the contact point and the alveolar crest, often after periodontal or orthodontic treatment or due to a triangular crown shape. A diastema is a gap between adjacent teeth. In both cases, composite has to be added to the tooth surface starting right at the gingival margin, rather than simply filling a cavity.
A flat strip has no tooth contour, which makes it difficult to create a natural emergence profile, avoid excess composite at the gingiva and achieve a smooth, easy-to-clean interproximal surface. Bioclear anatomic matrices were designed to solve exactly this problem.
How the Bioclear Method works
Bioclear was founded in 2007 in Tacoma (USA) by dentist Dr. David Clark. The manufacturer describes the method as a combination of updated tooth preparation, injection molding of heated composite and patented clear, anatomically shaped matrices.
- Anatomic matrix: it has the tooth contour, so the composite is shaped "around the tooth"; once sealed in the sulcus, the matrix stabilizes itself.
- Heated composite: flowable and paste composite are injected in a single flow, resulting in a continuous (monolithic) restoration.
- Curing through the matrix: the Mylar surface leaves a smooth interproximal composite that only needs finishing and polishing afterwards.
How to choose a matrix: black triangles and diastemas
Bioclear matrices are color-coded, and gauges help with selection. The main systems by clinical situation:
| Clinical situation | Bioclear matrices | What to watch for |
|---|---|---|
| Black triangle (canine to canine, both arches) | Black Triangle (BT) system | 2 sizes and 4 curvatures: blue for gaps up to 2.5 mm, green up to 2 mm, yellow up to 1.5 mm, pink up to 1 mm. The BT gauge indicates the curvature; the matrices do not need trimming. |
| Small gap, Class III cavity | HD or Original Anterior, A series | HD: 75 µm (stiffer); Original: 50 µm (more flexible). |
| Larger diastema | HD or Original Anterior, DC series | DC (Diastema Closure) matrices have a larger emergence profile. |
| Peg lateral incisors | BT and anterior matrices | Used to restore the tooth shape. |
| Full-coverage composite veneer | 360° Veneer matrix | For composite veneers; the TSS kit includes matrices for each surface of upper teeth 13–23. |
Step-by-step workflow
Below is a simplified outline based on the manufacturer's descriptions. The exact protocol depends on the case and is taught in Bioclear courses.
- Biofilm disclosing. A two-tone disclosing solution stains fresh biofilm pink and mature biofilm and cracks purple.
- Biofilm removal. The Blaster device with aluminum trihydroxide powder cleans the surfaces to be restored (according to the manufacturer, without damaging enamel).
- Contact preparation. TruContact 2.0 serrated saws and abrasive strips lighten the natural contact so that a Mylar matrix fits between the teeth.
- Matrix selection and placement. The matrix is selected with the BT gauge, seated in the sulcus and, if needed, stabilized with a Diamond Wedge.
- Injecting heated composite. Heated flowable and paste composite are injected into the matrix and cured.
- Finishing. After matrix removal, the restoration is finished and polished, for example with the two-step Rockstar Polish system.
Why the composite is heated
Injection molding relies on heated composite. In the Bioclear system, this is done with the HeatSync warmer, which heats composite to about 68 °C and holds this temperature; it holds two composite guns, two syringes and up to six additional compules. The manufacturer does not specify a single mandatory composite brand, so the specific choice is worth discussing during a consultation. To learn more about how heating changes composite flow, see our knowledge base article on composite warming and the AdDent CALSET warmer page.
What to discuss with the patient before the procedure
A black triangle or diastema is closed by adding composite, which changes the tooth contour, so it is worth showing this to the patient in advance, for example in photos or on a diagnostic model. Also discuss the following:
- Periodontal stability. Esthetic correction is best performed once the periodontal condition is under control; plan the correction of open interproximal spaces after periodontal treatment together with a periodontist.
- Interproximal hygiene. Smooth, anatomically shaped interproximal composite must be cleaned daily, so recommend suitable interdental cleaning aids to the patient.
- Direct, additive treatment. The method is often considered as an alternative to crowns or ceramic veneers because it preserves more healthy tooth structure.
- Follow-up visits. Composite restorations should be checked periodically and repolished when needed.
Who the Bioclear Method is for
The method is used by general dentists for everyday anterior and posterior composite restorations, by esthetic dentists for black triangles, diastemas and composite veneers, and by pediatric dentists. For periodontal teams, it is relevant for the esthetic correction of open interproximal spaces after periodontal treatment, working together with a general dentist.
Practical checklist before you start
- Assess the periodontal condition: black triangles often remain after periodontal treatment, so plan esthetic correction together with a periodontist.
- Measure the gap with the BT gauge and decide in advance whether you need BT, A or DC series matrices.
- Arrange biofilm disclosing and removal: a clean surface is the foundation of bonding.
- Have a warmer and a composite suitable for injection molding (flowable and paste consistency).
- Prepare contact preparation instruments, wedges and polishing tools.
- Plan for training: at least an introductory course helps avoid typical beginner mistakes.
Training and certification
Any dentist can use Bioclear products and procedures, but "Bioclear Certified Provider" status is granted only to those who have completed a Bioclear Learning Center course and received instructor certification. Good starting points are a one-day online introduction to injection molding (about 7 hours, with a kit of materials shipped to the participant) or the Black Triangle certification course, which consists of theory with a test, a one-day hands-on course and submission of your own cases. Core Anterior & Core Posterior and other courses are intended for advanced users.
How IMMT supports clinics
We are the official representative of Bioclear. We do not sell Bioclear products in our online store; instead, we:
- advise on which kit to choose based on the cases you want to treat;
- help you order matrices, kits and equipment through authorized supply channels and coordinate refills;
- demonstrate the matrix systems, HeatSync and Blaster;
- help you choose a Bioclear Learning Center course and keep you informed about training in the region.
Full information on the matrix families is available on the Bioclear Method page. Want to discuss your cases or see the system live? Contact IMMT and we will arrange a consultation or demo.
Frequently asked questions
Does closing a black triangle with the Bioclear method require grinding the tooth?
The method focuses on additive, minimally invasive treatment. Preparation usually involves biofilm removal and, if needed, light contact adjustment with TruContact strips; the exact extent depends on the case.
How do I choose a Black Triangle matrix?
The BT gauge is inserted into the black triangle, and its color indicates the required curvature: blue closes gaps up to 2.5 mm, green up to 2 mm, yellow up to 1.5 mm, pink up to 1 mm. The matrices come in two sizes – for small and large incisors.
Which matrices are designed for diastemas?
For larger gaps there is the DC (Diastema Closure) series with a more pronounced emergence profile, for smaller gaps the A series. Both series come in HD (75 µm) and Original (50 µm) versions.
Can Bioclear products be bought in the IMMT online store?
No. IMMT is the official representative of Bioclear but does not sell Bioclear products in the online store. Contact us and we will help you choose a kit and order through authorized channels.
Which composite should be used for injection molding?
The method relies on heated flowable and paste composites. The manufacturer does not specify a single mandatory brand, so we recommend discussing the specific choice during a consultation.
Is it mandatory to complete courses?
No, the products can be used by any dentist. However, we recommend at least an introductory course, and “Certified Provider” status is granted only after completing a Bioclear Learning Center course.