Severe gum disease affects more than 1 billion people worldwide. Bleeding, swelling, bad breath, receding gums or teeth that start to move are simple signs that justify a periodontal assessment.
If your gums bleed or are receding, or if periodontitis is suspected, Noria Health Hub can arrange a full check-up or a second medical opinion in Brussels, with a report within 24 h, coordinate your care where needed across more than 40 medical pathways in 48 h, then, if your medical condition allows, arrange surgery within 7 days.
Periodontitis: how common it is and what it costs
| What is measured | The figure |
|---|---|
| Prevalent cases of severe periodontitis worldwide in 2019 | 1.1 billion |
| Age-standardised global prevalence, stable 1990 to 2010 | 11.2%, 6th most frequent condition in the world |
| Share of the rise in case numbers 1990 to 2019 due to demographics alone | 67.9% |
| Peak incidence | Around age 38 |
| Annual indirect costs, productivity losses, Europe | 156 billion euros, that is 0.99% of gross domestic product |
The peak at 38 is the figure to remember. This is not a disease of old age, it is a disease that settles in mid working life and shows up in old age.
One honest reservation about these figures. Global estimates rest largely on partial-mouth examination surveys, which underestimate prevalence, and on definitions predating 2018. Country-level uncertainty intervals are very wide, up to 4.6 to 20.9% for a single country. We found no periodontal prevalence study in the Belgian general population, and we flag that rather than transpose.
Gum bleeding: most useful when it stays absent over time
This is the most useful result in the whole file, and it is counter-intuitive. Across 41 patients followed for 2.5 years in maintenance, the performance of bleeding on probing as a predictor of attachment loss is as follows.
| What is measured | The result |
|---|---|
| Sensitivity of frequent bleeding | 29% |
| Specificity | 88% |
| Positive predictive value | 6% |
| Negative predictive value | 98% |
A positive predictive value of 6% means 94 bleeding sites in 100 will do nothing. A negative predictive value of 98% means a site that never bleeds is stable. It is the repeated absence of bleeding that informs, not its presence.
Earlier work on 55 patients and 1,054 pockets gives the scale. A pocket bleeding 4 times out of 4 at recalls carries a 30% risk of attachment loss. At 3 out of 4, 14%. At 2, 6%. At 1, 3%. Never, 1.5%. So it is not bleeding on one day that counts, it is its repetition over time.
Periodontal treatment: the gains measured in pocket depth and attachment
The figures must be given in millimetres, because that is how they are measured and it avoids vague formulations.
| What is measured | The result |
|---|---|
| Pocket depth reduction, subgingival instrumentation, 9 studies | 1.4 mm at 6 to 8 months |
| Share of pockets closed | 74% |
| Hand against ultrasonic instruments, 6 randomised trials | No difference |
| Quadrant-wise against full-mouth treatment, 13 randomised trials | No difference |
| Shallow pockets | No significant improvement |
The 2 middle lines have a practical consequence. The type of instrument and the way the visits are split do not change the outcome. What changes the outcome is what is reached, and what is left behind.
And what is left behind is quantified. A cohort of 172 patients followed a mean of 11.3 years measures the risk of losing the tooth by residual depth after treatment. At 5 mm, the risk is multiplied by 5.8 compared with 3 mm or less. At 6 mm, by 9.3. At 7 mm or more, by 37.9. The authors conclude that a residual pocket of 6 mm or more represents incomplete treatment and calls for further therapy.
Periodontal surgery: in which situations?
| Pocket depth | What a flap adds over non-surgical treatment |
|---|---|
| Deep pockets, short term | +0.67 mm |
| Deep pockets, long term | +0.39 mm |
| Moderate pockets, short term | +0.34 mm, and nothing long term |
| Shallow pockets | −0.43 mm, that is additional attachment loss |
The last line should be known before any consent. On a shallow pocket, a flap loses attachment. The real differential in deep pockets is about 0.4 mm long term.
On regeneration of bone defects, the meta-analysis of 79 randomised trials and 3,042 patients finds an additional attachment gain of 1.34 mm over flap alone, with enamel matrix derivative at 1.27 mm and guided tissue regeneration at 1.43 mm. It must be added that only 10 of the 79 studies are at low risk of bias, and the strength of evidence is judged low to moderate.
Antibiotics: an average benefit that hides wide variation
A meta-analysis of 28 studies measures what a systemic antibiotic adds to mechanical treatment, 0.448 mm short term and 0.485 mm long term of additional pocket reduction. The result is statistically significant.
But the other number must be given, the one abstracts never highlight. The prediction interval of those same analyses runs from −0.10 to 0.99 mm and from −0.11 to 1.08 mm. In other words, in a new patient the expected benefit may be nil or slightly negative. That is what justifies the official European position, which is that routine systemic antibiotic use is not recommended, and that it may be considered for specific categories, for example generalised stage III periodontitis in young adults.
Smoking and diabetes: two major risk factors, and both can be changed
| What is measured | The result |
|---|---|
| Periodontitis risk in smokers, 14 prospective studies | Raised by 85%, relative risk 1.85 |
| Smoker against never smoker | Relative risk 1.82 |
| Former smoker against never smoker | Relative risk 0.97 |
| Periodontitis risk in people with diabetes, 13 studies, 49,262 people | Raised by 86%, relative risk 1.86 |
| Periodontitis to incident diabetes, 10 studies, 427,620 participants | Relative risk 1.26 |
The third line is the good news. After quitting, the risk returns to that of someone who never smoked. It is one of the few places in medicine where stopping erases the excess risk completely.
Maintenance: its association with long-term stability
The reference cohort followed 375 patients for 30 years, with recalls every 3 to 12 months as needed. Tooth loss over 30 years was 0.4 to 1.8 teeth by age group, and only 21 teeth in total were lost to periodontitis or progressive caries. The leading cause of loss was root fracture.
That result is striking and it must be read with its limit, which the authors themselves set out. All care was delivered in a single private practice, to self-selected, highly compliant patients. It is not a randomised trial, and none exists, because compliance is not randomised.
Meta-analyses give more modest and more transferable magnitudes. Regular compliance is associated with a relative risk of tooth loss of 0.56 in an analysis of 8 studies, and with an odds ratio of 1.26 of additional loss in non-compliant patients in another. The 2 figures differ because the definition of compliance varies between studies, and we prefer to say so.
Periodontitis and general health: association is not causation
This is the subject about which the most claims circulate, and it needs sorting.
| The link studied | The state of the evidence |
|---|---|
| Diabetes | Periodontal treatment lowers glycated haemoglobin by 0.43 points at 3 to 4 months, moderate certainty, 30 studies, 2,443 participants |
| Cardiovascular | Association independent of known confounders, but the reference cardiology authority writes that the data do not support a causal relationship |
| Pregnancy | Two large randomised trials, 823 and 1,760 participants, negative on preterm birth. Treatment is safe, it does not prevent prematurity |
| Rheumatoid arthritis | An elegant, documented biological mechanism, no intervention trial |
| Alzheimer’s disease | The only targeted treatment tested failed on its primary endpoint in phase 3. Reverse causation is highly plausible |
Only one line rests on interventional evidence of moderate certainty, the diabetes one. It is the only one we will put forward.
On the cardiovascular link, the best association study available is a case-control of 805 patients after a first myocardial infarction against 805 matched controls, with about a hundred confounding variables collected. The crude odds ratio is 1.49, and the adjusted odds ratio falls to 1.28, with an interval starting at 1.03. It is a real and modest association, in a design that does not demonstrate causation.
Implants: peri-implantitis is a complication of its own
A patient who has had periodontitis and is having implants placed should know these figures.
| What is measured | The result |
|---|---|
| Peri-implantitis at patient level, largest meta-analysis, 13,030 patients | 21% |
| Peri-implantitis in a random national Swedish sample, 9 years after placement | 45%, of which 14.5% moderate to severe |
| History of periodontitis | Odds ratio of 4.08 |
| Disease resolution after surgical treatment, 17 studies of at least 5 years | 58.6%, with 27.2% needing retreatment |
| Implants lost after peri-implantitis surgery, mean follow-up 7 years | 19.9%, on average 4.4 years later |
More than 4 cases in 10 are not resolved by surgery. That is why prevention and maintenance are worth far more than treatment, in this particular field.
Popular treatments: what has not shown the expected benefit
Three received ideas deserve correcting with figures.
Chlorhexidine. The Cochrane review of 51 studies and 5,345 participants finds a gingival index reduction of 0.21 on a 0 to 3 scale, which the authors explicitly judge not clinically relevant, while the effect on plaque is large. Tooth staining is consistent, with a standardised difference of 1.07. The antiplaque action is real, the effect on inflammation is not, in mild gingivitis.
Dental floss. The Cochrane review of 35 randomised trials and 3,929 participants finds low certainty evidence for floss and very low certainty for interdental brushes, and concludes that the effect sizes observed may not be clinically important. The European guideline places interdental brushes first and writes that floss is not suggested as a first choice.
Antibacterial toothpastes. The Cochrane review of 30 studies and 14,835 participants finds a 22% reduction in plaque and 48% in bleeding, of moderate quality. But on periodontitis at 36 months, a single study of 480 participants gives a relative risk of 0.92 with an interval including no effect. Nothing shows that an antibacterial toothpaste prevents attachment loss.
What the studies do not allow us to claim
We will not claim that looking after your gums protects your heart, because the reference cardiology authority says exactly the opposite about causation. Nothing entitles us to write that periodontal treatment prevents preterm birth, because 2 large randomised trials are negative. You will not read here that an antiseptic mouthwash treats periodontitis.
What we will say is that a site that never bleeds is 98% stable, that a residual pocket of 6 mm multiplies the risk of losing the tooth by 9, and that the only demonstrated general effect with moderate certainty is a fall in glycated haemoglobin in people with diabetes.
In practice, if this concerns you
You set out your problem, your symptoms or your question. Reports, test results and images already available can be studied before you arrive, so that the pathway is prepared. The aim is not to run every examination as a matter of course, but to select those that can genuinely help confirm a hypothesis, rule out a risk or guide the decision. The findings are then summarised and the next steps organised. Follow-up is coordinated afterwards.
Need medical advice quickly? For a concern that is not a matter for the emergency services, you can ask to speak to a doctor at any time through Noria Health Hub. This on-demand medical consultation is billed separately from the assessment pathway.
Further reading
The companion articles.
Replacing” rel=”noopener” target=”_blank”>https://noriahealth.com/blog/replacing-a-tooth-what-lasts-and-what-gets-repaired/”>Replacing a tooth: lifespan, complications and follow-up
Caries” rel=”noopener” target=”_blank”>https://noriahealth.com/blog/caries-the-most-widespread-and-the-least-well-decided/”>Caries, the most widespread disease
Sources
Chen MX, Zhong YJ, Dong QQ, Wong HM, Wen YF, Global, regional and national burden of severe periodontitis 1990 to 2019, Journal of Clinical Periodontology, 2021. https://doi.org/10.1111/jcpe.13506
Kassebaum NJ, Bernabé E, Dahiya M, Bhandari B, Murray CJ, Marcenes W, Global burden of severe periodontitis in 1990 to 2010, Journal of Dental Research, 2014. https://doi.org/10.1177/0022034514552491
Botelho J, Machado V, Leira Y, Proença L, Chambrone L, Mendes JJ, Economic burden of periodontitis in the United States and Europe, Journal of Periodontology, 2022. https://doi.org/10.1002/JPER.21-0111
Tonetti MS, Greenwell H, Kornman KS, Staging and grading of periodontitis, framework and proposal of a new classification, Journal of Periodontology, 2018. https://doi.org/10.1002/JPER.18-0006
El Sayed N, Rahim-Wöstefeld S, Stocker F, Behnisch R, Eickholz P, Pretzl B, The 2018 classification of periodontal diseases, its predictive value for tooth loss, Journal of Periodontology, 2022. https://doi.org/10.1002/JPER.21-0211
Lang NP, Adler R, Joss A, Nyman S, Absence of bleeding on probing, an indicator of periodontal stability, Journal of Clinical Periodontology, 1990. https://doi.org/10.1111/j.1600-051X.1990.tb01059.x
Lang NP, Joss A, Orsanic T, Gusberti FA, Siegrist BE, Bleeding on probing, a predictor for the progression of periodontal disease, Journal of Clinical Periodontology, 1986. https://doi.org/10.1111/j.1600-051X.1986.tb00852.x
Suvan J, Leira Y, Moreno Sancho FM, Graziani F, Derks J, Tomasi C, Subgingival instrumentation for treatment of periodontitis, a systematic review, Journal of Clinical Periodontology, 2020. https://doi.org/10.1111/jcpe.13245
Hung HC, Douglass CW, Meta-analysis of the effect of scaling and root planing, surgical treatment and antibiotic therapies on periodontal probing depth and attachment loss, Journal of Clinical Periodontology, 2002. https://doi.org/10.1034/j.1600-051X.2002.291102.x
Matuliene G, Pjetursson BE, Salvi GE, Schmidlin K, Brägger U, Zwahlen M, Lang NP, Influence of residual pockets on progression of periodontitis and tooth loss, Journal of Clinical Periodontology, 2008. https://doi.org/10.1111/j.1600-051X.2008.01245.x
Sanz-Sánchez I, Montero E, Citterio F, Romano F, Molina A, Aimetti M, Efficacy of access flap procedures compared to subgingival debridement, Journal of Clinical Periodontology, 2020. https://doi.org/10.1111/jcpe.13259
Nibali L, Koidou VP, Nieri M, Barbato L, Pagliaro U, Cairo F, Regenerative surgery versus access flap for the treatment of intrabony defects, Journal of Clinical Periodontology, 2020. https://doi.org/10.1111/jcpe.13237
Teughels W, Feres M, Oud V, Martín C, Matesanz P, Herrera D, Adjunctive effect of systemic antimicrobials in periodontitis therapy, Journal of Clinical Periodontology, 2020. https://doi.org/10.1111/jcpe.13264
Sanz M, Herrera D, Kebschull M, Chapple I, Jepsen S, Berglundh T, Sculean A, Tonetti MS, Treatment of stage I to III periodontitis, the EFP S3 level clinical practice guideline, Journal of Clinical Periodontology, 2020. https://doi.org/10.1111/jcpe.13290
Leite FRM, Nascimento GG, Scheutz F, López R, Effect of smoking on periodontitis, a systematic review and meta-regression, American Journal of Preventive Medicine, 2018. https://doi.org/10.1016/j.amepre.2018.02.014
Leite FRM, Nascimento GG, Baake S, Pedersen LD, Scheutz F, López R, Impact of smoking cessation on periodontitis, a systematic review and meta-analysis, Nicotine and Tobacco Research, 2019. https://doi.org/10.1093/ntr/nty147
Nascimento GG, Leite FRM, Vestergaard P, Scheutz F, López R, Does diabetes increase the risk of periodontitis, a systematic review and meta-regression, Acta Diabetologica, 2018. https://doi.org/10.1007/s00592-018-1120-4
Stöhr J, Barbaresko J, Neuenschwander M, Schlesinger S, Bidirectional association between periodontal disease and diabetes mellitus, Scientific Reports, 2021. https://doi.org/10.1038/s41598-021-93062-6
Axelsson P, Nyström B, Lindhe J, The long-term effect of a plaque control programme on tooth mortality, caries and periodontal disease in adults, 30 years of maintenance, Journal of Clinical Periodontology, 2004. https://doi.org/10.1111/j.1600-051X.2004.00563.x
Lee CT, Huang HY, Sun TC, Karimbux N, Impact of patient compliance on tooth loss during supportive periodontal therapy, Journal of Dental Research, 2015. https://doi.org/10.1177/0022034515578910
Simpson TC et al., Treatment of periodontitis for glycaemic control in people with diabetes mellitus, Cochrane Database of Systematic Reviews, 2022. https://doi.org/10.1002/14651858.CD004714.pub4
D’Aiuto F et al., Systemic effects of periodontitis treatment in patients with type 2 diabetes, a 12 month randomised controlled trial, The Lancet Diabetes and Endocrinology, 2018. https://doi.org/10.1016/S2213-8587(18)30038-X
Lockhart PB et al., Periodontal disease and atherosclerotic vascular disease, does the evidence support an independent association, Circulation, 2012. https://doi.org/10.1161/CIR.0b013e31825719f3
Rydén L et al., Periodontitis increases the risk of a first myocardial infarction, PAROKRANK, Circulation, 2016. https://doi.org/10.1161/CIRCULATIONAHA.115.020324
Michalowicz BS et al., Treatment of periodontal disease and the risk of preterm birth, OPT trial, New England Journal of Medicine, 2006. https://doi.org/10.1056/NEJMoa062249
Offenbacher S et al., Effects of periodontal therapy on rate of preterm delivery, MOTOR randomized controlled trial, Obstetrics and Gynecology, 2009. https://doi.org/10.1097/AOG.0b013e3181b1341f
Iheozor-Ejiofor Z, Middleton P, Esposito M, Glenny AM, Treating periodontal disease for preventing adverse birth outcomes in pregnant women, Cochrane Database of Systematic Reviews, 2017. https://doi.org/10.1002/14651858.CD005297.pub3
Konig MF et al., Aggregatibacter actinomycetemcomitans-induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis, Science Translational Medicine, 2016. https://doi.org/10.1126/scitranslmed.aaj1921
Dominy SS et al., Porphyromonas gingivalis in Alzheimer’s disease brains, Science Advances, 2019. https://doi.org/10.1126/sciadv.aau3333
Derks J, Tomasi C, Peri-implant health and disease, a systematic review of current epidemiology, Journal of Clinical Periodontology, 2015. https://doi.org/10.1111/jcpe.12334
Derks J, Schaller D, Håkansson J, Wennström JL, Tomasi C, Berglundh T, Effectiveness of implant therapy analyzed in a Swedish population, prevalence of peri-implantitis, Journal of Dental Research, 2016. https://doi.org/10.1177/0022034515608832
Galarraga-Vinueza ME, Pagni S, Finkelman M, Schoenbaum T, Chambrone L, Prevalence, incidence and risk factors for peri-implant diseases, systematic review and meta-analysis, Journal of Periodontology, 2025. https://doi.org/10.1002/JPER.24-0154
Romandini M, Bougas K, Alibegovic L, Hosseini S, Carcuac O, Berglundh T, Derks J, Long-term outcomes and prognostic factors of surgical treatment of peri-implantitis, Clinical Oral Implants Research, 2024. https://doi.org/10.1111/clr.14228
James P et al., Chlorhexidine mouthrinse as an adjunctive treatment for gingival health, Cochrane Database of Systematic Reviews, 2017. https://doi.org/10.1002/14651858.CD008676.pub2
Worthington HV et al., Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries, Cochrane Database of Systematic Reviews, 2019. https://doi.org/10.1002/14651858.CD012018.pub2
Riley P, Lamont T, Triclosan copolymer containing toothpastes for oral health, Cochrane Database of Systematic Reviews, 2013. https://doi.org/10.1002/14651858.CD010514.pub2
World Health Organization, Oral health fact sheet, 2025: severe periodontal disease affects more than 1 billion people. https://www.who.int/news-room/fact-sheets/detail/oral-health