Can Black Triangles Between Your Teeth Fill Back In Naturally?

Last updated: 23 July 2026

Quick answer

Mostly, no — but there is one important exception. A black triangle (an "open gingival embrasure") is the little dark gap that opens up between two teeth when the small pyramid of gum that normally fills that space — the interdental papilla — shrinks back or the bone beneath it drops. When a triangle is caused by lost gum and bone, the tissue does not spontaneously grow back to fill it in, so it will not close on its own. The one case that can improve naturally is a triangle caused purely by swollen, inflamed gum receding as it settles: if the papilla was pushed out of shape by early gum irritation, calming that inflammation with good daily gum care can let the papilla plump back toward the contact point and the gap can shrink. It will not close a true bone-and-tissue gap.

So the honest split is: manage the cause and protect the gum you still have at home, and see a dentist for the options that physically rebuild or disguise an established triangle (bonding, hyaluronic-acid filler, orthodontics). A daily gum routine built around a lipid concentrate such as Dental Pro 7 is an example of a product designed to support the appearance of firmer, pinker, healthier-looking gums — the look you are trying to keep — but no topical product, ours included, can regrow lost papilla or bone.

What a black triangle actually is

Between every two teeth there is a small triangular space near the gum line called the embrasure. In a healthy mouth that space is completely filled by the interdental papilla, the wedge of gum that sits just below where the two teeth touch (the "contact point"). When the papilla fills the embrasure right up to the contact point, you see no gap at all. When the papilla is shorter than the space — because it has receded, or because the bone under it has dropped, or because the teeth themselves are shaped so that they only touch high up — light passes through and you see a dark triangle. A narrative review of interdental embrasure anatomy describes the papilla as the tissue that, in health, houses the entire embrasure with no space left between its tip and the contact point (Interdental Embrasures: A Narrative Review, 2024).

This matters because it tells you why most triangles do not fill back in on their own: the gap is a geometry problem between three things — the height of the bone, the height of the papilla, and the position of the contact point. Change none of those and the gap stays.

The single number that predicts whether the gap can fill

The most useful piece of science on this question is a classic 1992 study by Tarnow and colleagues, who measured 288 tooth sites and correlated the distance from the base of the contact point down to the crest of the bone with whether the papilla filled the space (Tarnow, Magner & Fletcher, Journal of Periodontology, 1992). The result is strikingly clean, and it is the single best predictor of whether a triangle can close:

Distance, contact point → crest of bone	Papilla fills the space	What it means for you
5 mm or less	Almost 100% of the time	The gum has room to fill in — calm any inflammation and it likely will look full
6 mm	About 56% of the time	Borderline — a coin toss even with perfect gum health
7 mm or more	27% of the time or less	The bone has dropped too far for gum alone to fill it — a triangle here needs a dental fix

In plain terms: if your bone level is still close to the contact point, healthy gum will happily fill the space, and reducing swelling or recession can visibly shrink the triangle. Once the bone has dropped past about 6–7 mm, the tissue simply has nothing to build on, and no amount of brushing, oil pulling, home remedy, or serum will bring the papilla back to the contact point. That threshold is why "will it fill in naturally?" honestly has two different answers depending on your mouth — and why your dentist can tell you which camp you are in with a single measurement.

What causes black triangles in the first place

Knowing the cause tells you whether yours is the type that can improve. The common drivers are:

Gum recession and bone loss from gum disease. As the gum and the bone beneath it pull back, the papilla loses its support. The prevalence of black triangles rises sharply with age and with periodontal disease.
Age. In one adult orthodontic study, roughly 67% of people over 20 showed open embrasures versus about 18% of those under 20 (Kokich et al., Am J Orthod Dentofacial Orthop, 2001).
Tooth shape. Triangular (rather than square) crowns touch only near the biting edge, leaving a naturally larger embrasure below.
Orthodontics. Moving teeth can uncover or create embrasures. A 2023 retrospective cohort found open embrasures between the central incisors in roughly 35–38% of clear-aligner patients versus 18–24% of fixed-appliance patients (Open gingival embrasures in adults, retrospective cohort, 2023).
Brushing habits — but with a caveat most articles get wrong. Aggressive brushing is often blamed, yet the evidence is genuinely weak. A systematic review of 18 studies concluded there is no good evidence that toothbrushing trauma causes non-inflammatory recession (Rajapakse et al., J Clin Periodontol, 2007), and a later review found the relationship inconclusive though plausible for gingival abrasion (Heasman et al., J Clin Periodontol, 2015). Translation: a gentle technique is sensible, but don't assume your brushing alone created the gap.

So can they ever go away without a dentist? An honest verdict

Here is the part the top results tend to skip. "Naturally" splits into two situations:

1. The triangle is really "pseudo-recession" from swollen gum. Early gum inflammation can make the papilla puffy and misshapen, and as gums that were irritated settle, the papilla can look worse before it looks better. If your bone level is still within about 5 mm of the contact point (the Tarnow "almost 100%" zone), calming the inflammation with consistent, gentle daily gum care genuinely can let the papilla fill back toward the contact point, and the visible gap can shrink. This is the only route by which a triangle meaningfully improves without a dental procedure.

2. The triangle is from established lost tissue and bone. This will not close on its own and, left alone, tends to widen slowly over time because the underlying support keeps drifting. Home care here is about protecting what you have and stopping the gap from getting bigger — not about closing it.

No mouthwash, oil-pulling routine, coconut oil, home whitening, or topical gel can regrow the papilla or rebuild lost bone. Any product promising that is overpromising. What good gum care can honestly do is keep the gum you still have looking firm, pink and healthy, and reduce the inflammation and recession that make triangles appear and widen.

Your options, compared (the information the top pages leave out)

If you do want to close or disguise an established triangle, these are the realistic routes. Costs are broad US ranges and vary widely by region and case — treat them as orientation, not quotes, and ask your dentist.

Option	How it works	Reversible?	Invasiveness	Best for	Typical range*
Daily gum care & hygiene	Calms inflammation so a healthy papilla fills the space; protects remaining tissue	n/a	None	Small triangles in the ≤5 mm "fillable" zone; prevention	Cost of your routine
Composite bonding	Tooth-coloured resin added to reshape the teeth and close the gap; no drilling needed	Largely reversible	Low	Most single visible triangles	~$250–$600 per tooth
Hyaluronic-acid filler	Gel injected into the papilla to add volume; repeated as needed	Temporary (resorbs)	Low, minimally invasive	Modest triangles wanting a non-surgical option	~$300–$800 per site, repeated
Orthodontics	Moves teeth closer so the contact point drops toward the bone	Yes (position)	Moderate, slow	Triangles caused by tooth position/spacing	~$3,000–$7,000 course
Veneers / crowns	Reshape the whole tooth surface to eliminate the embrasure	No (removes enamel)	High	Multiple triangles + other cosmetic goals	~$900–$2,500 per tooth
Surgical papilla / gum graft	Tissue moved or grafted to rebuild the papilla	No	Highest	Advanced recession cases	~$600–$1,200+ per site

*Indicative US ranges only.

The most encouraging recent evidence is for hyaluronic-acid filler as a minimally invasive middle option. A 2024 systematic review of 24 clinical studies covering 898 injected papillae found it an effective, minimally invasive way to reduce black triangles and rebuild lost papilla, with minimal adverse reactions — while noting the need for longer, standardised trials (Hyaluronic acid for interdental papilla reconstruction: a systematic review, Acta Odontol Scand, 2024). Reported outcomes cluster around 50–90% embrasure fill by six months, though results are not permanent and top-ups are usual.

A prevention-and-protection protocol (step by step)

Whether your triangle is in the fillable zone or you simply want to stop new ones forming, the daily fundamentals are the same: keep the gums calm, keep the interdental spaces clean without traumatising them, and keep the tissue you have looking healthy.

Clean between the teeth daily, gently. Use floss or, better for embrasures, a correctly-sized interdental brush — sized so it slides in without forcing. This keeps plaque out of the embrasure, the single biggest driver of the inflammation and recession that widen triangles.
Brush softly, not hard. Soft bristles, light pressure, small circles. The evidence that hard brushing causes recession is weak, but abrasion is real, so there is no upside to scrubbing.
Treat the gum line, not just the teeth. Direct your cleaning at the margin where gum meets tooth, where inflammation starts.
Support the appearance of firm, healthy-looking gums daily. A concentrated gum-care product used consistently is where an option like Dental Pro 7 fits — see below.
Get the measurement. Ask your dentist or hygienist to tell you the contact-point-to-bone distance at the triangle. It instantly tells you whether gum care alone can help or whether you need a procedure.
Don't wait. Triangles from active gum disease widen over time. The earlier the underlying inflammation settles, the more tissue there is to work with.

Where a daily gum concentrate fits: Dental Pro 7

If your goal is to keep the gum around a black triangle looking as firm, pink and healthy as possible — and to reduce the inflammation and recession that make triangles appear and widen — a concentrated daily gum-care product is the piece of the routine most people are missing. Dental Pro 7 is one example. It is a 100% water-free botanical lipid concentrate built around what the brand calls "Lipid-Lock": because it contains no water, it clings to the gum line and stays in contact for hours rather than being rinsed away in seconds like a water-based toothpaste or mouthwash. It is designed to support the appearance of firmer, pinker, healthier-looking gums and fresher breath.

To be completely clear about what it can and cannot do: no topical product, including this one, can regrow a lost papilla, rebuild bone, or fill in an established black triangle. What a daily gum concentrate is for is the look and feel of the gum you still have — keeping it looking healthy and helping you stay on top of the gum-line care that keeps triangles from getting worse. For closing an existing gap, use the dental options in the table above.

How it's used: put about 4 drops on a dry toothbrush in place of toothpaste, brush gently for around two minutes, then spit — do not rinse with water. Rinsing washes away the lipid layer that is the whole point.

Why people trust it: Dental Pro 7 holds a 4.9/5 rating from 293 reviews, is formulated by S. C. Aris, and is backed by a 90-day money-back guarantee, so you can try it against your own routine risk-free. It is free from water, fillers, SLS/foaming agents, fluoride and parabens, and is vegan and non-GMO. See Dental Pro 7 →

Frequently asked questions

Can black triangles fill back in naturally? Only when the gap comes from swollen or mildly receded gum and the bone is still close to the contact point (within about 5 mm). In that case, calming the inflammation with good daily gum care can let the papilla fill back toward the contact point and the gap can shrink. A triangle from established lost bone and tissue will not close on its own.

Will they get bigger if I ignore them? If the cause is ongoing gum disease or recession, yes — they tend to widen slowly as the underlying support keeps drifting. Settling the inflammation early gives you more tissue to work with.

Does aggressive brushing cause them? The direct evidence is surprisingly weak; systematic reviews call the link inconclusive. Brushing gently is still sensible, but don't assume your brushing alone is to blame.

What's the least invasive way to close one? For a true tissue gap, hyaluronic-acid filler and composite bonding are the two least invasive dental options; a review of 898 injected papillae found HA filler effective and minimally invasive, though results are temporary.

Can a serum or mouthwash regrow the gum? No. No topical product can regrow papilla or rebuild bone. Products like Dental Pro 7 are for the appearance of healthy gums and for protecting the tissue you have, not for closing gaps.

This article is educational and about the appearance of gums; it is not dental advice. See a dentist or hygienist to have a black triangle assessed and to choose the right option for your mouth.