Care & Protection: Santé bucco-dentaire

What It Is

Two diseases cause almost everything that goes wrong in the mouth, and both are largely preventable. Dental caries is the decay of enamel by acid that plaque bacteria make from sugar. Periodontal disease inflames the gum and slowly destroys the bone that holds the teeth in place. The claims that reach beyond the mouth fall into three tiers. The diabetes link is sturdiest. The cardiovascular link is an association whose cause is unsettled. The Alzheimer connection is the least settled of the three.

The Research & Studies

Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.

Oral Health

Le dentifrice fluoré prévient environ 24 % des caries dentaires infantilesStrong

In plain terms

Se brosser les dents avec un dentifrice fluoré plutôt que non fluoré prévient environ un quart des caries dentaires chez les enfants, et le bénéfice augmente avec des concentrations de fluor plus élevées et un brossage plus régulier. C'est la chose la plus solidement établie que vous puissiez faire pour vos dents.

In detail

Marinho et al. (Cochrane 2003) ont regroupé 70 essais randomisés ou quasi-randomisés avec évaluation en aveugle des résultats, tous d'au moins un an, comparant un dentifrice fluoré à un placebo. La fraction prévenue de 24 % était cohérente dans une large base de données probantes que les auteurs de la revue décrivent comme relativement de haute qualité, soutenue par plus d'un demi-siècle de recherche. L'hétérogénéité était réelle mais expliquée par la dose et la fréquence : plus le fluor était concentré et plus il était utilisé souvent, plus l'effet était important. Il y a peu de données sur les dents de lait ou sur la fluorose comme dommage.

Who this may not transfer to:Measured mostly in children; fluoride toothpaste is accepted to work in adults too, though the pooled figure here is from pediatric trials.

The study · 1

Marinho et al., Fluoride toothpastes for preventing dental caries in children and adolescents · Cochrane Database Syst Rev 2003;(1):CD002278

More sugar means more decay; under 10% of calories tracks with lessModerate · risk

In plain terms

Plus vous consommez de sucre, et plus souvent, plus vous avez de caries dentaires. Maintenir le sucre ajouté sous environ un dixième des calories quotidiennes s'accompagne d'une nette diminution des caries, et encore moins est encore mieux.

In detail

Moynihan and Kelly (J Dent Res 2014) reviewed 55 studies (3 intervention, 8 cohort, 20 population, 24 cross-sectional). The studies measured sugar and caries so differently that a formal meta-analysis was not possible, which is why the tier is moderate, not strong despite the near-unanimous direction. Frequency matters as much as total amount: each sugar exposure is an acid attack, so sipping and snacking through the day is worse than the same sugar in one sitting.

Who this may not transfer to:Measured in children and adults of both sexes; the sugar and decay link applies to anyone with teeth.

The study · 1

Moynihan and Kelly, Effect on caries of restricting sugars intake: systematic review to inform WHO guidelines · J Dent Res 2014;93(1):8-18

Powered brushes remove 11% to 21% more plaque than manual onesModerate

In plain terms

An electric toothbrush removes a bit more plaque and leaves gums slightly less inflamed than a manual one, roughly a tenth to a fifth less plaque over time. The gap is small but consistent, and a manual brush used well still does the job.

In detail

Yaacob et al. (Cochrane 2014) pooled 51 trials. The reviewers rate the evidence moderate but note the clinical importance of a 6% to 11% gingivitis reduction is uncertain, and heterogeneity between trials was high. Reported side effects were local and temporary. Technique, coverage and time spent brushing matter more than the type of brush, so the electric brush is a small assist, not a substitute for brushing well twice a day.

Who this may not transfer to:Measured in adults of both sexes; the small plaque and gum benefit applies to adult brushers generally.

The study · 1

Yaacob et al., Powered versus manual toothbrushing for oral health · Cochrane Database Syst Rev 2014;(6):CD002281

Cleaning between the teeth reduces gum inflammation, on low-certainty trialsEmerging

In plain terms

Cleaning between the teeth, by floss or an interdental brush, on top of brushing, reduces bleeding, swollen gums. The trials are short and small so the certainty is low, but the direction is toward benefit, and interdental brushes look at least as good as floss.

In detail

Worthington et al. (Cochrane 2019). The low certainty comes from short trial durations (many only four weeks), participants who already had healthy gums, and the impossibility of blinding people to whether they floss. That lack of large, long, high-quality trials is why the popular line that flossing is unsupported took hold; a shortage of definitive trials is a different thing from trials showing flossing does nothing, and what evidence exists points to less gum inflammation.

Who this may not transfer to:Measured in adults of both sexes; cleaning between the teeth applies to anyone with natural teeth to clean between.

The study · 1

Worthington et al., Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries · Cochrane Database Syst Rev 2019;4(4):CD012018

Xylitol in a fluoride toothpaste may cut decay 13%, on thin evidencePreliminary · mixed

In plain terms

Xylitol may add a small amount of decay protection when it is inside a fluoride toothpaste, but the evidence is thin and comes mostly from one research group. For lozenges, sweets and other xylitol products the studies do not show a clear benefit.

In detail

Riley et al. (Cochrane 2015). The one positive signal, a 13% reduction, rests on two trials by the same authors in the same population, so it should be read cautiously. Most other xylitol formats produced effect estimates that spanned both benefit and harm, meaning the data cannot say whether they help. No adverse effects were reported from the toothpastes; higher-dose xylitol products can cause bloating, cramps and loose stools.

Who this may not transfer to:Trials spanned infants to adults of both sexes; the findings apply broadly, though the toothpaste signal comes from one population.

The study · 1

Riley et al., Xylitol-containing products for preventing dental caries in children and adults · Cochrane Database Syst Rev 2015;(3):CD010743

Oil pulling did not beat mouthwash or brushing in the trialsPreliminary · no effect

In plain terms

Swishing oil around the mouth did not beat standard mouthwash or ordinary brushing for plaque or gum inflammation in the trials that tested it. Those trials were small and lasted only a few weeks, so the case for oil pulling as more than a supplement to the basics is weak.

In detail

Gbinigie et al. (Complement Ther Med 2016) included five small RCTs of varying reporting quality. Oil pulling does not remove toxins from the body, and any oral benefit is consistent with the mechanical effect of swishing any liquid, not a property of the oil. It has not been shown to add anything on top of fluoride brushing and interdental cleaning, and it should not replace them.

Who this may not transfer to:Measured in adults of both sexes; the null result applies generally.

The study · 1

Gbinigie et al., Effect of oil pulling in promoting oro dental hygiene: a systematic review of randomized clinical trials · Complement Ther Med 2016;26:47-54

Blood Sugar

Treating gum disease lowers HbA1c about 0.43% in people with diabetesModerate

In plain terms

In people with both diabetes and gum disease, a deep professional cleaning of the gums lowered long-term blood sugar by about 0.4 percentage points of HbA1c, a clinically useful amount. The effect eased somewhat by six months.

In detail

Simpson et al. (Cochrane 2022) doubled the evidence base of the earlier review and upgraded the conclusion: periodontal treatment improves glycemic control by a clinically significant amount versus no treatment or usual care. The relationship runs both ways, since high blood sugar worsens gum disease and gum inflammation worsens blood sugar. Many trials were at high risk of bias, but a sensitivity analysis limited to low-risk trials supported the finding.

Who this may not transfer to:Measured in adults of both sexes, almost all with type 2 diabetes; it applies to adults who have both conditions.

The study · 1

Simpson et al., Treatment of periodontitis for glycaemic control in people with diabetes mellitus · Cochrane Database Syst Rev 2022;4(4):CD004714

Heart And Vascular

Gum disease is associated with heart disease, though shared causes cloud itEmerging · risk

In plain terms

People with gum disease do tend to have more heart and artery disease. A large part of that overlap is because the same things, smoking, aging and diabetes, drive both, and the studies cannot fully separate the gum disease itself from the company it keeps.

In detail

Lockhart et al. (Circulation 2012), the AHA scientific statement, appraised more than a century of proposed links. It found the association survives adjustment for some shared risk factors, which is why it deserves to be taken seriously, but it is explicit that observational studies cannot show causation and that periodontal treatment has not been shown to prevent cardiovascular disease. The fair reading is a real, adjusted association of uncertain cause, not a demonstrated chain from gums to heart.

Who this may not transfer to:Drawn from mixed-sex observational studies of adults; the association shows up across both sexes.

The study · 1

Lockhart et al., Periodontal disease and atherosclerotic vascular disease: does the evidence support an independent association? A scientific statement from the American Heart Association · Circulation 2012;125(20):2520-2544

Treating gum disease has not been shown to prevent heart attacks or strokesPreliminary · no effect

In plain terms

Even though gum disease travels with heart disease, treating the gums has not been shown to prevent heart attacks or strokes. The trials that would answer this have not been done well enough to say, so the popular claim that fixing your gums protects your heart runs ahead of the evidence.

In detail

Ye et al. (Cochrane 2022) found no new completed RCTs since the 2019 update and could include only two small high-risk trials, whose one-year outcomes were very low-certainty and inconclusive. The correct reading is that the cardiovascular benefit of periodontal treatment is currently unknown, because adequate trials have not been done, not that treatment has been shown to do nothing. Look after your gums for your mouth and, if you have diabetes, for your blood sugar, and treat any heart-protection as an open question.

Who this may not transfer to:The two trials enrolled adults of both sexes; the absence of adequate evidence applies to everyone.

The study · 1

Ye et al., Periodontal therapy for primary or secondary prevention of cardiovascular disease in people with periodontitis · Cochrane Database Syst Rev 2022;10(10):CD009197

Fertility

Treating gum disease in pregnancy did not clearly reduce preterm birthEmerging · no effect

In plain terms

Scaling and cleaning the gums during pregnancy did not clearly reduce premature birth in the trials, though it may have nudged down the rate of low-birth-weight babies. Gum care in pregnancy is safe and reasonable, but it is not a reliable way to prevent preterm labor.

In detail

Iheozor-Ejiofor et al. (Cochrane 2017) pooled 15 trials in pregnant women with periodontitis or gingivitis, all at high risk of bias. The main result on preterm birth was null, and the low-birth-weight signal was of low quality. Dental care during pregnancy is safe and worthwhile for the mother's own oral health; the evidence does not support recommending it as a way to prevent preterm birth.

Who this may not transfer to:Measured only in pregnant women, which is the population the outcome applies to.

The study · 1

Iheozor-Ejiofor et al., Treating periodontal disease for preventing adverse birth outcomes in pregnant women · Cochrane Database Syst Rev 2017;6(6):CD005297

Cognition

A gum bacterium turns up in Alzheimer brains, but the causal case rests on micePreliminary · risk

In plain terms

A gum-disease bacterium and its enzymes have been found in Alzheimer-affected brains, and in mice the same bug damaged neurons. It is an early and much-discussed hypothesis, not a settled cause, and a drug built on it did not work when it was tested in people.

In detail

Dominy et al. (Sci Adv 2019). The human part is autopsy tissue showing the bacterium and correlations with pathology; the causal part is mouse and laboratory work. The study was run by Cortexyme, a company developing a gingipain inhibitor, and that drug (atuzaginstat) later did not meet its primary endpoint in a human Alzheimer trial. The link is a live area of research, worth watching, but not a reason to fear that gum disease will give you Alzheimer disease.

Who this may not transfer to:Based on human autopsy tissue and mouse experiments, so sex was not a study variable.

The study · 1

Dominy et al., Porphyromonas gingivalis in Alzheimer's disease brains: evidence for disease causation and treatment with small-molecule inhibitors · Sci Adv 2019;5(1):eaau3333

How It Works

Both diseases come down to a chemical exchange on the surface of the enamel. Acid dissolves mineral out of the enamel: demineralization, and saliva puts it back: remineralization. Frequent sugar shifts the balance toward loss.

Anatomy of the Practice

1The tooth and the plaque on it

A tooth is a hard enamel shell over living dentine and a pulp of nerve and blood supply. Within hours of cleaning, a film of bacteria called plaque forms on the surface and along the gumline. Left there, it is the start of both decay and gum disease.

2How decay and gum disease begin

When you eat sugar, plaque bacteria turn it into acid. Every separate sip or snack is a fresh acid attack that dissolves a little enamel. Plaque left along the gumline inflames the gum; this early stage is gingivitis. In some people the inflammation deepens into periodontitis and erodes the bone under the tooth.

3How the mouth affects the body

Periodontitis is a chronic open wound of inflamed tissue. Its bacteria and inflammatory signals can enter the bloodstream. That is one plausible route from the mouth to the body. There is a second: gum disease and diseases elsewhere share drivers such as smoking, aging, and diabetes. Together the two explain why the associations hold even where the cause is unconfirmed.

Fluoride shifts the balance back: it raises the enamel's resistance to acid and speeds redeposition. Cleaning does the rest, stripping plaque before it can make acid or inflame the gum. Brushing covers the outer and inner faces of the teeth. Cleaning between the teeth reaches the surfaces where two teeth meet, the first place gum disease tends to take hold.

That is why fluoride does more against decay than any other single step.

What Changed

Three widely shared beliefs about the mouth have shifted as the evidence came in. In 2016, a wave of news coverage reported that the evidence for flossing was weak. The reviews behind it did flag the trials as short, small, and low in certainty. But low-certainty evidence means the large, long trials are missing. It does not show that cleaning between the teeth achieves nothing. The studies that exist still point toward less gum inflammation from floss or an interdental brush. Fluoride toothpaste, by comparison, rests on far firmer evidence.

The belief that gum disease causes heart attacks began with a sound observation: people with gum disease have more heart and artery disease. The correction is about cause. Much of the overlap comes from the shared drivers named above. One result would prove cause: treat the gums and watch heart attacks fall. Trials good enough to show that have not been done.

Charcoal toothpaste is sold on the promise that it whitens and cleans better than ordinary paste. It does neither in the tests that exist. It is abrasive enough to wear the enamel, and many charcoal pastes contain no fluoride at all.

Getting the Basics Right

The same small set of habits prevents both decay and gum disease.

Ways to Do It

The benefit here comes from daily habit, and the first two steps prevent most decay. Little of it costs anything.

1

Brush twice a day with a fluoride toothpasteFree to $Easy

This is the foundation, the step with the strongest evidence behind it. Use a fluoride toothpaste morning and night. After brushing at night, spit but do not rinse, so a little fluoride stays on the teeth. A pea-sized amount is enough for an adult. Fluoride protects by sitting on the enamel. It does not need to be swallowed, and for young children swallowing is the real risk. So children use less, with an adult watching. Under age 3, a smear the size of a grain of rice. From ages 3 to 6, a pea-sized amount, with a grown-up there to see the child spit it out.

2

Get the technique and the time rightFreeEasy

Two minutes, small gentle circles angled at the gumline, covering every surface. A soft brush protects the gums; hard bristles and hard scrubbing wear the teeth and gums.

3

Clean between the teeth once a dayFree to $Easy

Once a day, run floss or an interdental brush between every pair of teeth. Interdental brushes work at least as well as floss and are easier for many people. The best tool is the one you will use every day.

4

Cut sugar, and, above all, eat it less oftenFreeModerate

Frequency matters as much as amount. Sweets kept to mealtimes, with water in between, give the enamel time to recover; sugary drinks sipped through the day are the worst pattern for teeth. The sugar behind this is largely industrial. Sugar-sweetened drinks are the single largest source of added sugar in the American diet. Added sugars supply about 13% of daily calories for the average American, above the 10% ceiling the Dietary Guidelines set.

5

See a dentist regularly$ to $$Easy

A professional clean removes the hardened plaque a brush cannot, and a check-up catches decay and gum disease while they are small and cheap to fix. How often depends on your risk; your dentist will set the interval.

Home care covers the everyday risk, and a handful of signs mean a dentist should take over.

Cautions For This Practice

Everything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.

Charcoal toothpaste whitens less and wears enamel more

Tomas et al. (Ann Anat 2023) synthesized in vitro work on extracted teeth and enamel. Beyond the abrasion, many charcoal products contain no fluoride, which removes their protection against decay, and the black particles can lodge in gum margins and around fillings. The evidence is laboratory-based, not from long human use, but nothing in it supports charcoal as a safe or effective way to whiten.Tomas et al., Effectiveness and abrasiveness of activated charcoal as a whitening agent: a systematic review of in vitro studies

Bleeding gums are an early sign to act on

Gums that bleed when you brush or clean between the teeth are usually inflamed, an early stage of gum disease, and worth acting on. In the first week or two of cleaning between the teeth, some bleeding is common and settles as the gums heal. Bleeding that persists beyond that, or bleeding with loose teeth, receding gums, lasting bad breath, or pain, is a reason to see a dentist. Sudden or heavy gum bleeding can occasionally reflect a wider health problem, so a professional look is sensible.

A cracked or persistently painful tooth needs a dentist promptly

Lingering toothache, sensitivity to hot and cold that does not fade, facial or gum swelling, or pain on biting are warning signs. They can mean decay has reached the nerve, or an infection. These do not resolve on their own and are far easier to treat early. Home care lowers day-to-day risk; an established cavity or abscess still needs a dentist.

Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.

Go Deeper

• Type 2 diabetes: the sturdiest oral-systemic link, where gum disease and blood sugar each affect the other.
• Whole foods and ultra-processed foods: how ultra-processed food builds frequent sugar into the diet, the pattern that drives tooth decay.
• Dietary fiber: whole-food carbohydrates come packaged with fiber, feeding the body without the frequent acid hits of refined sugar.
• Inflammation: the shared inflammation behind the mouth-body link, and the biology of a chronic inflamed wound.
• The microbiome: plaque is a living bacterial film, and the balance of microbes in the mouth shapes both decay and gum disease.

The Chinese Medicine View

In Chinese medicine, the teeth are an outgrowth of the Kidney. They are the surplus of the same Kidney essence, or Jing, that also builds bone and marrow and sets the constitution you are born with. Strong Jing shows as sound teeth. A decline in Kidney essence, with age or through depletion, shows as teeth that loosen or weaken. So when an older adult's teeth loosen, the tradition reads it first as that deep reserve running low, not just as a local problem with the tooth.

The gums belong to a different system. The Stomach channel passes through the upper gum and the Large Intestine channel through the lower, so the gums are read mainly through the Stomach. Red, swollen, bleeding, or painful gums are typically read as Stomach heat. That heat often comes from rich, greasy, spicy, or over-sweet food, rising along the channel to the mouth. A practitioner treats swollen gums by clearing that heat from the channel, working on the diet behind it as much as the mouth itself.

This lens maps loosely onto modern dentistry, where a sugary, inflammatory diet does aggravate gum inflammation. What the tradition adds is a way to fit the mouth into the whole person: the teeth tied to the deep constitution and aging, the gums to digestion and diet.

Common Questions

Do I really need to floss?

Daily cleaning between the teeth matters; whether you floss is a smaller question than whether you clean at all. The habit rests on lower-certainty evidence than fluoride, because the long, large trials have not been run. What evidence exists still shows healthier, less inflamed gums.

Is an electric toothbrush better than a manual one?

Pooled trials show electric brushes remove roughly 10–20% more plaque over time and leave the gums slightly less inflamed than manual ones. The reviewers call that edge modest and its clinical importance uncertain.

Can gum disease really affect the rest of my body?

Yes, most clearly with diabetes. High blood sugar makes gum disease worse, and gum inflammation makes blood sugar harder to control. Treating periodontitis lowers HbA1c, a three-month blood-sugar measure, by a clinically useful amount in trials. The heart-and-artery link is an association that shares those risk factors, and the benefit of gum treatment for the heart stays unconfirmed. A proposed tie between a gum bacterium and Alzheimer's rests on animal and laboratory work, an early hypothesis, still short of a proven cause.

Does oil pulling work?

In the small trials that tested it, a few weeks each, swishing oil did no better than ordinary mouthwash or brushing for plaque or gum inflammation. It does not draw toxins from the body. If you enjoy it, it is unlikely to harm your teeth, as long as it sits on top of fluoride brushing and daily cleaning, never replacing them.

What is the single most important thing I can do?

Fluoride toothpaste has more evidence behind it than any other step. Brush with it twice a day.