Knowledge5 min read
Tartar: how it forms and why brushing alone will not remove it
Dear patients, our second article finally turns to dentistry proper: it is about tartar. Put simply, tartar is the hardened form of soft dental plaque: hard, yellowish-white to brownish, with a rough surface. We all have it, we all know it. Tartar is probably as old as humanity itself and remains the subject of current research, and not only in dentistry. In archaeology, too, tartar samples taken from skeletons offer a glimpse of our ancestors' oral flora.
Today, though, we want to cover the basics. Understanding tartar is the first step towards understanding periodontal disease. For many patients, periodontal disease and its inflammatory form, periodontitis, are still a blind spot.
Once tartar has formed, no toothbrush will remove it. It often forms within 24 to 48 hours, in some cases after as little as 12 hours, above the gum line, and it forms particularly quickly and readily where salivary glands are nearby. That is why we so often find tartar between the upper first molars and on the lower incisors, exactly where the ducts of our major salivary glands open. Tartar that forms below the gum line, from the fluid in the periodontal pockets, is called a concrement.
For those who would like a little more detail: on closer inspection, tartar is highly complex and forms an ecosystem of its own. It consists of two components, one inorganic and one organic. The hard part is made up of various calcium phosphate compounds and originates in our saliva. The second component is soft dental plaque, which consists of proteins, carbohydrates and microorganisms.
But how does tartar actually form? Immediately after we brush our teeth, salivary proteins settle on the tooth surface and form the pellicle, a very thin film. One important job of this thin biofilm is to remineralise our teeth. Beyond a certain thickness, the biofilm begins to act like a sponge and bacteria attach to it as well. Through their metabolism, the bacteria in the plaque change the pH. As the pH rises, the solubility of calcium phosphate falls and minerals precipitate out. And this is where it becomes interesting: inside this outwardly solid structure there are niches, pores, channels and tunnel systems in which bacteria can carry on living undisturbed. There they are safe from the "good bacteria" in our saliva, from antibacterial mouth rinses, and even from antibiotics.
If you look at the tooth surface very closely, you see that it is not perfectly smooth; there are small pores and irregularities. Plaque and its crystals grow right into these small pores and effectively "take root" in the tooth.
Once things have reached this point, no water flosser, no dental floss and no sonic or electric toothbrush will help. Only an ultrasonic scaler or hand instruments can gently release these anchorings.
I hope these rather detailed explanations help you understand the complex structure of tartar. In a future article we will look at the effects of tartar on our gums and at new approaches to dealing with it. Perhaps understanding how tartar forms is good motivation to use dental floss or interdental brushes. From my conversations with patients I know that most of them use dental floss. Irregularly, but still more often than the German average, which is a solid starting point.
In a representative YouGov Germany survey from June 2019 (2,056 respondents), 35% said they cleaned between their teeth once or twice a day. 15% did so at most once a month, or never.
So now we know that it is really only the frequency that needs to go up: for most people once a day, for a few twice a day. So, take the floss out of the drawer, and here is the pro tip: put the floss right on top of your toothbrush so that using it becomes unavoidable. The motivation is there in all of us, after all these are our own teeth; usually it is only the follow-through that is missing. So, the clock is ticking. You have 12 to 48 hours. Have fun trying it out!
This article provides general information and does not replace individual dental advice.
Sources
- Lindhe J, Lang NP. Clinical Periodontology and Implant Dentistry. 7th edition, Wiley, 2022.
- Newman MG, Klokkevold PR, Elangovan S, Kapila Y, Carranza FA, Takei H. Newman and Carranza's Clinical Periodontology and Implantology. 14th edition, Elsevier, 2023.
- Marsh PD. Dental Plaque as a Biofilm and a Microbial Community. Caries Research, 2004.
- Hannig M, Joiner A. The structure, function and properties of the acquired pellicle. Monographs in Oral Science, 2006.
- Warinner C et al. Ancient dental calculus and the evolution of the oral microbiome. Philosophical Transactions of the Royal Society B, 2015.
- Sälzer S et al. EFP S3 Clinical Practice Guideline. Journal of Clinical Periodontology, 2020.
- EFP S3 guideline on periodontitis (2020), DG PARO guideline.
- YouGov Germany. Online survey on oral hygiene, June 2019 (2,056 respondents). Cited from: ZWP online, "Fakten mit Biss: So halten es die Deutschen mit der Zahnpflege", zwp-online.info.
Last updated: July 2026
Illustrations: hand sketches by Johannes Fernandes, finished drawings and cover image by Claude Opus 5 based on those sketches.
AI assisted with research and structuring (source research: ChatGPT; revision and proofreading: Claude Sonnet 5). Content and statements have been reviewed and are the professional responsibility of Johannes Fernandes. How this blog is made
