Black triangles and a furcation

Correct answer: C. Interproximal reduction and reshaping to move the contact point apically

• A. Papilla regeneration techniques exist and are described, but their outcomes in the maxillary anterior region remain unpredictable and are not the answer to a routine post-orthodontic black triangle.
• B. Grafting can thicken the tissue but does not reliably rebuild an interdental papilla. Surgical reconstruction of a lost papilla is widely regarded as the least predictable procedure in periodontal surgery, because the blood supply and the confined interproximal space work against it.
• C. CORRECT. Whether the papilla fills the embrasure is governed by the distance from the CONTACT POINT to the CREST OF BONE — Tarnow's finding: at 5 mm the papilla is present almost 100% of the time, at 6 mm about 56%, and at 7 mm only about 27%. This patient measures 7 mm. Since the bone crest cannot readily be moved coronally, the practical solution is to move the CONTACT POINT APICALLY and close the space — interproximal reduction with orthodontic space closure, or reshaping and adding with composite bonding or veneers to lengthen the contact area incisogingivally. Triangular incisors that touch only at the incisal tip are the anatomy that produces this, and IPR plus bonding is the standard combination.
• D. Intrusion would move the contact point further from the bone crest and make the triangle worse. Orthodontic EXTRUSION, by contrast, brings bone and papilla coronally and is a legitimate adjunct in selected cases.

Note: Prevention outranks correction here. Black triangles typically appear after orthodontic alignment of crowded triangular incisors, and after periodontal therapy resolves oedematous papillae. Both groups of patients should be warned BEFORE treatment starts. Note also that the spaces are not purely a liability — they permit effective interdental brush cleaning.

Correct answer: A. A Class II buccal furcation or a narrow two- to three-wall intrabony defect

• A. CORRECT. GTR works by placing a barrier membrane that excludes the fast-migrating gingival epithelium and connective tissue from the root surface, so that the slower periodontal ligament and bone cells can repopulate it and form a new attachment. That requires a CONTAINED, SELF-SUPPORTING SPACE with surrounding bony walls. The best-documented indications are therefore a mandibular Class II buccal furcation and a NARROW, DEEP two- or three-wall intrabony defect — the more walls and the narrower the defect angle, the better the result.
• B. Horizontal bone loss offers no contained defect at all — there are no walls to support a clot or a membrane, so there is nothing for regeneration to work with. It is managed non-surgically or with resective surgery.
• C. A Class III furcation is through-and-through. The space cannot be contained or maintained under a membrane, and regeneration there is not predictable. Class III defects are managed by root resection, hemisection, tunnel preparation or extraction.
• D. The one-wall or hemiseptal defect is the LEAST favourable of the intrabony defects for regeneration, precisely because only a single wall remains to support the blood clot and the barrier. Such defects are usually treated by osseous resection instead.

Note: Maxillary furcations respond poorly to GTR because of root proximity, trunk anatomy and access. Smoking substantially reduces regenerative outcomes and is a relative contraindication. Plaque control and resolution of inflammation must be established BEFORE any regenerative surgery, and the defect must be diagnosed by careful probing and, ideally, bone sounding rather than radiographs alone.