Evidence grade: C — Anecdote / folk / A2 — Institutional literature Effort: N/A — debunk, no procedure
Verdict: MYTH. Toothpaste cannot fix a cracked phone screen, and it cannot polish a real scratch out of glass. Its abrasives are too soft and too fine to cut glass, it has no bonding or filling properties, and the rubbing can force paste into cracks, damage the oleophobic coating, and seep into ports.
Legend
The trick is one of the internet's oldest phone myths: dab non-gel toothpaste on the scratch, rub in circles with a soft cloth, wipe clean. The folk logic is that toothpaste is "mildly abrasive" — true for teeth — so it should buff the scratch away. Proponents often cite toothpaste's RDA (Relative Dentin Abrasivity) numbers as if they measured polishing power.
Evidence
The mechanism doesn't transfer. Toothpaste abrasives are designed to clean dentin — far softer than display glass. Reviewers who tested the claim conclude the abrasive particles are too soft and fine to effectively polish the glass surface, and toothpaste has no adhesive or bonding properties to seal cracks or restore structural integrity [1].
RDA numbers prove nothing about glass. Published RDA tables rank toothpastes from about 4 (plain water brushing) to 200, with the FDA's recommended limit at 200 and the ADA's at 250 [2]. But RDA measures abrasion of dentin — tooth material — under a specific brushing protocol. A higher RDA does not mean "polishes glass better"; the number is simply not a glass metric. Citing RDA values as evidence for screen repair is a category error.
The real risks. The same debunking notes the downsides: abrasive particles can lodge in cracks and worsen damage, aggressive rubbing can harm the underlying display, paste can seep into charging ports and cause corrosion, and DIY attempts can void the warranty [1]. At best, paste may temporarily reduce the visibility of a hairline scratch by filling it with dried residue — cosmetic masking, not repair, and it crumbles away [1].
Verdict: MYTH
No type of toothpaste repairs cracked or scratched phone glass — not gel, not whitening, not baking-soda formulas [1]. The honest options are a screen protector to hide a light scratch, or professional screen replacement for real damage.
Honest limits
- This article addresses glass display screens. Plastic screen protectors scratch differently, but toothpaste isn't the fix for those either.
- The RDA table cited is a dental-industry reference (Kois, Seattle), not a screen-testing source — cited here precisely to show what RDA does and doesn't measure.
Sources
- AEANET — "Can Toothpaste Really Fix A Cracked Phone Screen?" — abrasives too soft/fine for glass; no bonding properties; risks include lodged particles, port damage, warranty — https://www.aeanet.org/can-toothpaste-really-fix-a-cracked-phone-screen/
- RDA (Relative Dentin Abrasivity) toothpaste table — values ~4–200; FDA recommended limit 200; ADA recommended limit 250; 0–70 low abrasive — https://d1ajls23knb7pl.cloudfront.net/wp-content/uploads/sites/16/2016/10/19180102/Toothpaste-Abrasiveness.pdf
Repair Lab · Release 1 · Evidence last checked September 30, 2026 · A project of AOJEL