Could zinc make cavity treatment simpler, painless and drill-free?

Now, researchers at New York University (NYU) are advancing a promising alternative: a zinc-based treatment that could stop cavities, relieve pain, and avoid the aesthetic drawbacks associated with current non-invasive options (1,2).

Silver Diamine Fluoride (SDF): Effective caries control, but aesthetic limitation

SDF is a simple and effective non-invasive treatment for arresting dental caries, particularly in children, older adults, and patients unable to undergo conventional care. Its main drawback is permanent black staining of treated lesions, which limits acceptance in visible teeth. This has prompted interest in alternatives such as zinc-based agents that may provide similar benefits without discolouration (3).

Why Zinc? —A promising alternative

Zinc is widely used in oral care products for its antibacterial, anti-plaque, and anti-gingivitis effects. It also supports remineralisation and helps reduce sensitivity when combined with agents like hydroxyapatite. Unlike silver, zinc does not cause tooth staining, making it a more aesthetically acceptable option for managing dental caries (4).

Targeting dentinal tubules from within

A key issue in both caries control and dentine hypersensitivity is the structure of dentine, which contains thousands of microscopic tubules that connect directly to the pulp. These tubules allow bacterial movement and fluid shifts that trigger sensitivity.

Effective treatment, therefore, needs to go beyond surface action. It must penetrate these tubules and block them by forming stable mineral deposits that reduce bacterial activity and fluid flow.

Recent laboratory studies on human teeth have shown that zinc-based solutions can enter dentinal tubules and form mineral precipitates such as zinc phosphate and related compounds. These deposits can partially or fully block the tubules, reducing both bacterial penetration and sensitivity signals.

Early research often used multi-step application systems, but newer work is focusing on simpler, single-step zinc formulations that are more suitable for clinical use (2, 5).

The NYU zinc tetra-ammine difluoride development

Researchers at NYU have developed a clear zinc-based liquid to help manage dental caries and dentine hypersensitivity without causing silver-related staining. Applied directly to exposed dentine, the zinc complex breaks down in the moist environment and forms insoluble zinc compounds that block dentinal tubules.

This rapid tubule occlusion, visible within minutes in laboratory studies, produces tooth-coloured mineral deposits that avoid the dark discolouration associated with Silver Diamine Fluoride. The deposits may remain stable for weeks to months while slowly releasing zinc and fluoride ions.

Zinc exhibits antimicrobial activity against cariogenic bacteria such as Streptococcus mutans, while fluoride promotes remineralisation and protects against further demineralisation. Although early findings are promising, the technology is still preclinical, and clinical trials are needed to confirm its long-term effectiveness and safety (2,5,6).

Zinc in the broader caries literature

The NYU programme does not exist in isolation. A broader body of work helps contextualise what zinc might offer.

Zinc induces apatite and scholzite formation during dentine remineralisation. This in vitro study immersed demineralised dentine in zinc chloride and zinc oxide solutions and found remineralisation after 24 hours, with effects maintained up to 1 month (7).

Clinical research on zinc oxide nanoparticles used as cavity disinfectants after selective caries removal has reported marked reductions in S. mutans counts, on the order of high double-digit percentage reductions, demonstrating zinc’s capacity as a potent antimicrobial adjunct in minimally invasive operative procedures (8).

Trials of zinc-hydroxyapatite systems in patients with erosive lesions have shown earlier improvements in sensitivity and objective lesion indicators when zinc-HAp dressings are added to toothpaste regimens, compared with toothpaste use alone (9).

Taken together, these lines of evidence suggest that zinc can provide a combination of antimicrobial activity, dentinal tubule sealing, and symptom relief. The NYU zinc tetraammine difluoride system extends this logic into a targeted, potentially SDF-like agent that aims to arrest early caries and control sensitivity without compromising aesthetics (5).

A future without drilling?

If successful, this zinc-based treatment could significantly reshape preventive and restorative dentistry. Instead of removing decayed tissue through drilling, dentists may be able to halt early decay with a simple application.

Such an approach could reduce patient anxiety, shorten appointment times, and improve access to care, particularly in paediatric dentistry, elderly populations, and underserved communities.

In the long term, researchers envision a product that is not only used in clinics but may also be available in simplified formulations for broader preventive use.

Conclusion

While further testing and clinical validation are still required, the development of a zinc-based cavity treatment represents a significant step forward in minimally invasive dentistry. By combining antimicrobial action, rapid tubule sealing, and a non-staining profile, this innovation could offer a practical and patient-friendly alternative to traditional cavity management and potentially mark a shift towards a future where drilling is no longer the default solution for tooth decay (2, 5,6).

References

1. World Health Organization. Oral health. Available from: https://www.who.int/news-room/fact-sheets/detail/oral-health

2. New York University. (2025, September). Inventing a next-generation cavity fighter. NYU News. https://www.nyu.edu/about/news-publications/news/2025/september/zinc-cavity-treatment.html

3. Zheng FM, Yan IG, Duangthip D, Gao SS, Lo ECM, Chu CH. Silver diamine fluoride therapy for dental care. Jpn Dent Sci Rev. 2022 Sep 7;58:249–257. doi:10.1016/j.jdsr.2022.08.001. PMID:36097; PMCID: PMC9463534.

4. Srisilapanan P, Roseman J, Likitsatian T. Clinical effect of toothpaste and mouth rinse containing zinc lactate on oral malodour reduction. J Clin Exp Dent. 2019 Apr 1;11(4):e346–e352. doi:10.4317/jced. 55418. PMID:31110614; PMCID: PMC6522105.

5. Dental Tribune International. Zinc compound offers non-staining alternative to silver diamine fluoride. Dental Tribune. 2025 Oct 24.

6. Barros A. A new cavity-fighter that ditches silver in the works [Internet]. DrBicuspid. 2025 Oct 13.https://www.drbicuspid.com/dental-hygiene/fluoride/article/15768829/a-new-cavityfighter-that-ditches-silver-in-the-works

7. Osorio R, Osorio E, Cabello I, Toledano M. Zinc induces apatite and scholzite formation during dentine remineralisation. Caries Res. 2014;48(4):276–290. doi:10.1159/000356873. PMID:24513585.

8. Scribante A, Pardo A, Pascadopoli M, Biagi F, Schiepatti A, Giammona V, Vecchio M, Alquati C, Modica GG, Casu C, Butera A. Remineralising treatments for dental erosion and sensitivity in patients suffering from gastroesophageal reflux disease (GERD): randomised clinical trial. J Clin Med. 2025 May 18;14(10):3525. doi:10.3390/jcm14103525. PMID:40429520; PMCID: PMC12111895.

9. Khattab S, Raafat R, Riad M. Evaluation of the antibacterial efficacy of diode laser and zinc oxide nanoparticles as cavity disinfectants following partial caries removal: a randomised controlled clinical trial. BDJ Open. 2025 Dec 16;11:96.

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