Full-Mouth Black Triangle Treatment Protocol

Jihyon Kim, DDS, and David J. Clark, DDS
0 Shares

A GROWING PROBLEM
The prevalence of adult orthodontics has risen about 40% since 1996. The American Association of Orthodontists reports that, in 2012, more than 1.2 million orthodontic cases were for adults.1 Much of the demand is due to an increase in social acceptance, discreet orthodontic treatment options, a mature generation with disposable income, an increase in longevity, proactive attitudes about health, and a desire to maintain youthfulness and attractiveness. People want the impression of youth and vigor associated with straight white teeth, along with the confidence and perceived social advantages that come with an attractive smile.

The irony is that almost 40% of adult orthodontic treatments result in black triangles,1,2 which patients may consider a greater aesthetic issue than crowded teeth.3 A study assessing the layperson’s perception of aesthetic concerns suggests the threshold for patient awareness and dislike of black triangles to be 3.0 mm.4 Considering the increase in patient awareness and aesthetic demands, this could be an overestimate. In fact, the majority of black triangles we have been asked to treat average 1.0 to 1.5 mm. Black triangles have many etiologies (Table 1).2,5

Table 1. Etiology of Black Triangles2,5

  • Decreased interproximal bone height from periodontal disease, attachment loss, periodontal surgery, or trauma
  • Excessive embrasure space and deficient papilla form affected by root angulation, interradicular distance, crown form, and distance between alveolar bone and interproximal contact
  • Patients’ biologic width and inherent or thinning gingival biotype
  • Other: Age, patient habits, iatrogenic issues.

Poor Options for Managing Black Triangles
Our profession’s strategies for managing the black triangle issue range broadly. Ideally, we avoid black triangle formation but inform patients of their predilections. Or, we ignore the problem and hope that patients will also. The latter response is not due to professional insensitivity, but rather conventional solutions that are costly, invasive, unpredictable, and unstable (Table 2).2,6,7

Table 2. Conventional Solutions for Black Triangles2,6,7

  • Orthodontic extrusion, to coronally reposition interproximal bone, and subsequent enameloplasty or restoration
  • Orthodontic repositioning of divergent roots or widely spaced roots along with enameloplasty to narrow the embrasure space and encourage gingival adaptation
  • Interproximal bone graft
  • Soft-tissue graft or papilla reconstruction
  • Subtractive porcelain restorations or composite bonding (white and/or pink)
  • Removable prosthesis in severely compromised cases.

We Cannot, and Should Not, Ignore the Problem
The question of how to treat open gingival embrasures, or “black triangle disease,” has largely stumped dental professionals. Yet, the occurrence of black triangles in people 20 years and older may be as high as 67%. The dilemma is increasing prevalence (especially with certain dental procedures) and patient awareness. If we cannot avoid the problem, we should not ignore it as a mild aesthetic issue. For many patients, it has a significant negative impact on their smiles and quality of life. Besides the obvious aesthetic concerns, patients can also suffer from functional and clinical concerns related to black triangles2 (Table 3).

Table 3. Functional/Clinical Concerns with Black Triangles

  • Retention of food debris or biofilm accumulation and potential tissue inflammation
  • Lateral compaction of food debris, creating uncomfortable wedging pressure between tightly spaced roots
  • Phonetic issues: escape of air or saliva during speech
  • Iatrogenic narrowing of roots with repeated scaling to remove calculus.

What Can We Do?
Reviewing the clinical options, the reasonable choices are papilla reconstruction for limited areas or orthodontics, either alone or with restorative options. Yet, what if the defects are extensive or large? What if orthodontics has contributed to the problem, and is no longer part of the solution? Orthodontic resolutions are limited by parameters for maintaining an aesthetic maxillary central width-to-height (W/H) ratio of 80% (± 5%), aesthetically pleasing relative proportions of maxillary anteriors, and Bolton ratios for appropriate interarch relationships.

Surgical options are unpredictable and may not be reasonable for extensive areas. Indirect restorations can extract a high biologic cost. Many patients are unwilling to sacrifice sound tooth structure to treat black triangles, especially if the condition can progress with age. Historically, composite bonding has been too difficult to obtain a long-term healthy and aesthetic result. Black triangles in the aesthetic zone were treated only if requested; the treatment was definitely not considered for the entire mouth.

Table 4. Benefits of Black Triangle Treatment with Bioclear

  • Noninvasive, additive method
  • Simple and predictable: the technique can be learned and applied by the average clinician
  • Smooth subgingival contours for tissue adaptation and health
  • Mylar finish for minimal calculus accumulation and easy removal, minimizing iatrogenic root contouring with repeated scaling
  • Protective coverage of root surfaces, reducing sensitivity
  • Broad incisal-gingival and buccal-lingual contacts, leading to ortho­dontic stability.

Negative Space: How We See and Perceive It
Negative space is the space surrounding and defining the boundaries of positive space occupied by an object. The human visual system is more sensitive to contrast than absolute luminance. In other words, the human eye sees contrast between black and white or complimentary colors more readily than soft-color contrasts. As a result, our visual focus on an object or area is enhanced when surrounded by the stark contrast of negative space.

In dentistry, we have familiar negative space (meaning negative space in an expected area), such as the dark oral cavity backdropping the incisal edge contours of a smile. We take photographs with a black contrast to enhance this. Such familiar negative space can either highlight pleasing symmetry and contours or bring attention to unaesthetic contours. Black triangles are seen when papilla deficiency is significant enough that saliva can no longer mask the dark contrast against the white tooth. At a certain threshold, it becomes a significant aesthetic concern, because unfamiliar negative space (meaning negative space in an unexpected area) can connote disease and decay.

Should We Focus on White Instead of Pink?
Most of our solutions to black triangles focus on amplifying the deficient papilla. We are attempting to recreate the ideal balance of pink (the soft tissue) and white (the hard tissue or restoration) aesthetics. We strive for perfection in orthodontic treatment of children. With adults, we need a reasonable solution for a compromised clinical situation. As much as we should strive for an ideal solution, if all else fails, or if the morbidity with treatment is high, should we accept the best compromise?

When we consider aesthetic tolerances in dentistry, both dentists and laypersons tolerate asymmetries in pink aesthetics more than asymmetries in white aesthetics.6 White aesthetics seemingly trump pink aesthetics, likely due to how our eyes see more of a stark contrast. As professionals, we focus on the micro aesthetics (teeth and gingiva) and mini aesthetics (the smile arc and the tooth proportion and position) that compose a pleasing smile.8 We should also consider laypeople’s aesthetic tolerances. Patients have greater tolerances for mini- and micro-aesthetic discrepancies and focus more on elements of macro aesthetics (facial composition).4,8 For most patients, noninvasively replacing a black triangle with something that is white (tooth colored) may be a preferable compromise over unpredictable surgical options to replace pink soft tissue.

The Bioclear Method is unique in making a direct restorative solution to black triangles both simple and predictable. It is very different from traditional composite bonding in technique and results. The following case, treated by author Dr. Jihyon Kim, demonstrates Bioclear’s potential in full-mouth black triangle treatment. This case highlights how the Bioclear Method can offer an innovative and noninvasive approach for finishing orthodontic treatments.

CASE REPORT
Diagnosis and Treatment Planning

A 40-year-old male patient presented with minimal restorative history, stable periodontal status, and excellent home care. His chief complaint was the generalized black triangles present between all interproximal contacts following orthodontic treatment. A stated secondary concern of his was the generalized mild/moderate tetracycline staining of all dentition.

Our treatment goal was to minimize or eliminate the open gingival embrasures while also minimizing the amber color gradation present in the gingival half of the anterior teeth. The only tooth preparation involved the removal of an old incisal composite restoration on the left central incisor (tooth No. 9), then prepping a functional aesthetic bevel on the facial aspect. All other treatment was completely additive. Other than the preparation required for tooth No. 9, no other tooth reduction was done.

Figure 1. Preoperative (left) and postoperative (right) full-face photos of the patient.
Figure 2. Pre-op and post-op photos of his closed smile.
Figure 3. Pre-op and post-op photos of the frontal retracted view.
Figure 4. Pre-op and post-op photos of the patient’s right side buccal retracted view.
Figure 5. Pre-op and post-op photos of the patient’s left side buccal retracted view.
Figure 6. Pre-op and post-op photos of the maxillary incisors.
Figure 7. Pre-op and post-op photos of the mandibular incisors.

The Bioclear Method is a solution to treat black triangles by focusing on adding white predictably and noninvasively. Even though the ideal balance of pink and white was not achieved, the result was a significant improvement that satisfied the patient’s aesthetic goals (Figures 1 to 7). The radiographs reveal the smooth subgingival restorative contours that lend a favorable tissue response (Figures 8 to 10).

The preoperative photos demonstrate an ideal W/H ratio of the maxillary central incisors and the aesthetic presentation of the smile (Figures 11 and 12). What is evident is the tapered crown form and incisally positioned point proximal contacts contributing to the large interdental embrasure spaces. Even if the arch form allowed for interproximal reduction and closer orthodontic positioning of roots, compromises in tooth proportions and smile perspective would have occurred; and black triangles, although minimized, would still persist. Also, the impact on Bolton ratios would possibly compromise interarch relationships.

Figure 8. Pre-op and post-op radiographs of the left posterior quadrant. Observe the smooth subgingival contours.
Figure 9. Pre-op and post-op radiographs of the maxillary anteriors.
Figure 10. Pre-op and post-op radiographs of the mandibular anteriors.

Clinical Protocol
The Bioclear Method is simple and prescriptive. One of the pillars of the method is biofilm removal. The treatment is done using rubber dam isolation (Hygenic 6”x6” Heavy Gauge Dental Dam [Midwest Dental Equipment]). Proper isolation is critical for biofilm staining with a two-tone disclosing agent, and subsequent mechanical removal with an aluminum trihydroxide spray. Rubber dam isolation is also critical for soft-tissue retraction and papilla compression. A minimum 1.0- to 1.5-mm subgingival restorative contour is necessary to apply lateral compression to existing papillae.7 Lateral pressure helps to mold the papilla to fill any embrasure space not already filled by composite. Other than the bevel prep on tooth No. 9, the remaining teeth are made ready for this procedure by removing the biofilm with the aluminum trihydroxide spray delivered via the Bioclear Blaster (Figures 13 and 14).

The appropriate Bioclear matrices were selected to create an anatomic “aquarium,” or containment. Flowable and paste composites were heated to 155°F for ideal flow in a HeatSync heater (Bioclear), then injected into the form created by the matrices (Figures 15 and 16). Wedge placement is neither recommended nor necessary. The anatomic contour of the matrices, along with the rubber dam cuff around the cervical portion of the teeth, make the matrix aquarium self-sealing. It is important to note the subgingival extension of the matrices in the case photos presented here (Figures 17 to 20).

Figure 11. The Smile Design Gauge
(Bioclear) shows the relative perspective of the anterior teeth. The central incisor width is about 9.5 mm.
Figure 12. The central incisor is about 12 mm in length, giving an ideal width-to-height ratio of 79%.
Figure 13. The isolated, disclosed, and blasted arch and the only prepped tooth (No. 9). Figure 14. The Bioclear Blaster and Dual Color Disclosing agent.
Figure 15. Bioclear Anterior Matrix-Esthetics Kit (A101 to A105).

The teeth were treated using the total-etch technique, then rinsed and dried. Next, a universal adhesive (Scotchbond Universal Adhesive [3M]) was applied, followed by heated flowable composite that was then chased with heated paste composite. Then, 3M Filtek Supreme XTE Flowable paste composite (shade B1 Body) was used and cured. After the matrix removal, excess buccal and lingual composite was quickly removed and shaped with large coarse discs (Sof-Lex [3M]) while avoiding marring the smooth Mylar finish left by the matrices. Initial polishing was done using Magic Mix (Bioclear) applied with a rubber cup, then rinsed. The final polishing was done using a Jazz Polisher (SS White Burs) to achieve a stain-resistant high shine.

CLOSING COMMENTS
“Black triangle disease” is a growing concern for patients. Our current options for treatment are unpredictable and can be biologically costly. The Bioclear Method is a unique solution that offers great potential for finishing orthodontic cases. The method enables a clinician to treat black triangles in areas previously deemed unreasonably difficult by focusing on white instead of pink, and macro-aesthetics of a smile. The solution fulfills most patients’ aesthetic desires while preserving their dentition, contributing to Bioclear’s rapid rise in demand (Table 4).

Figure 16. Bioclear HeatSync composite heater.
Figure 17. Bioclear A101 HD on mesial and A102 HD on distal of tooth No. 9. Figure 18. Immediately after injection
overmolding and matrix removal.
Figure 19. Bioclear A101 HD on mesial and A102 HD on distal of teeth Nos. 8 and 9 were sculpted with a large coarse disc (Sof-Lex [3M]). Figure 20. Bioclear A105 HD on mesial and distal of tooth No. 12.

In closing, the authors wish to share the following heartfelt words from a patient, who also happens to be a dentist:

“Bioclear has made me a much happier person. That is no hyperbole. I am naturally a very smiley person. Most of my life, I had been complimented on my beautiful smile. But a couple of years ago, I lost it.

“My story began with my first orthodontic treatment (at 17 years old) and the appearance of my first black triangle between tooth Nos. 23 and 24. I wasn’t concerned, since it was not visible when smiling or speaking.

“In dental school, I noticed posterior black triangles, but multiple periodontist consults yielded no solution. Gradually, despite very conscientious home care, more black triangles developed. Then, around age 38, with my third round of orthodontics, my central papilla disappeared.

“In insidious and subtle ways, the loss of my central papilla made me very self-conscious of all my black triangles. I stopped smiling broadly, giving only a practiced semi-smile to hide my gumline. I rarely removed my mask while speaking to patients. New patients made me uncomfortable. I believed they would negatively judge the dentistry I could deliver, due to the appearance of my teeth. I also believed that those who did not know me, including fellow professionals, might question my personal hygiene. Finally, I felt old and unattractive, losing confidence as my gumline receded. However, with Bioclear, I am back! I’m smiling, confident, and happier!”


References

  1. Kurth JR, Kokich VG. Open gingival embrasures after orthodontic treatment in adults: prevalence and etiology. Am J Orthod Dentofacial Orthop. 2001;120:116-123.
  2. Tanaka OM, Furquim BD, Pascotto RC, et al. The dilemma of the open gingival embrasure between maxillary central incisors. J Contemp Dent Pract. 2008;9:92-98.
  3. Cunliffe J, Pretty I. Patients’ ranking of interdental “black triangles” against other common aesthetic problems. Eur J Prosthodont Restor Dent. 2009;17:177-181.
  4. Kokich VO Jr, Kiyak HA, Shapiro PA. Comparing the perception of dentists and lay people to altered dental esthetics. J Esthet Dent. 1999;11:311-324.
  5. Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol. 1992;63:995-996.
  6. Machado AW. 10 commandments of smile esthetics. Dental Press J Orthod. 2014;19:136-157.
  7. Spear FM. Interdisciplinary esthetic management of anterior gingival embrasures. Inside Dentistry. 2007;3(3).
  8. Brandão RC, Brandão LB. Finishing procedures in orthodontics: dental dimensions and proportions (microesthetics). Dental Press J Orthod. 2013;18:147-174.

Dr. Kim is co-director and full faculty of Bioclear Learning Center (BLC) International in Tacoma, Wash. She actively teaches and develops new curriculum for BLC. She also maintains a full-time patient practice in Tacoma and Bellevue, Wash. She can be reached via email at jihyonkim@bioclearmatrix.com.

Disclosure: Dr. Kim is co-director and full faculty of BLC International. She also has finanical interest in Bioclear’s Smile Design Gauge.

Dr. Clark is the inventor of Bioclear. He is also co-director and full faculty at BLC International. He maintains a full-time patient practice in Tacoma, Wash. He can be reached via email at drclark@bioclearmatrix.com.

Disclosure: Dr. Clark is the inventor of Bioclear. He is also co-director and full faculty at BLC International.

Related Articles

Composite Versus Ceramics, Part 1: Young Patients and Fractures

Dr. Clark’s 3-Step Composite Finishing

Biofit With David Clark, DDS