Plaque and Calculus: What They Are and Why One Cannot Be Brushed Away
For anyone asking about plaque or tartar: plaque is a soft film of bacteria that constantly forms on the teeth, and calculus (tartar) is plaque hardened with minerals. This page covers how plaque forms, how fast it hardens, calculus above and below the gum, disclosing tablets and tartar-control toothpaste. The Oral Health Foundation says only the dental team can remove tartar.
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Clinically reviewed by Dr Ibraheem Ijaz, dentist · GDC 301711
Medical disclaimer: This page is for general information only. It does not replace an examination or treatment by a dentist.
Dr Ibraheem Ijaz, GDC 301711, a General Dental Practitioner and principal dentist at Deepcar Dental Care, reviewed this page. His qualifications include BDS, BSc (Hons) and MSc (Leeds).
What is dental plaque?
Dental plaque is a thin, sticky film of bacteria that constantly forms on your teeth, the Oral Health Foundation (OHF) explains.
Delivering Better Oral Health (DBOH), the UK prevention toolkit, describes plaque as a highly organised film of bacteria in an organic matrix made up of micro-organisms and their by-products.
Plaque contributes to gum disease and tooth decay, the NHS says. Our pages on gingivitis and tooth decay cover each condition.
How does a plaque biofilm form?
A plaque biofilm forms in stages on a coating of saliva proteins, a 2002 review in Critical Reviews in Oral Biology and Medicine explains.
Salivary proteins settle on the tooth to form a layer called the acquired pellicle, and micro-organisms then attach to it; through co-aggregation and co-adhesion, some that cannot attach on their own join them. Once they attach, the review says, new genes could be switched on, so that mature plaque can form and its bacteria become more resistant to antimicrobial agents.
How fast does plaque turn into tartar?
Plaque left on the teeth can harden into calculus over several days, says Great Ormond Street Hospital (GOSH), an NHS trust.
In a 1999 clinical trial designed to produce calculus quickly, calculus had formed in every group 14 days after a professional clean to remove all plaque and calculus, on lower front teeth treated with toothpaste in a fitted shield rather than brushed.
In a 1997 study of 15 people, calculus formed on the inside of the lower front teeth over 30 days varied widely, scoring from 0.5 to 15.
Plaque you leave on your teeth can harden into tartar, the Oral Health Foundation says, and it calls the toothbrush, toothpaste and cleaning between your teeth the main weapons of daily care.
Why can't calculus be brushed off?
Calculus resists brushing because it is plaque hardened into a cement-like substance that a toothbrush cannot remove, Great Ormond Street Hospital explains.
Calculus is mostly calcium phosphate mineral laid down between and inside the remains of once-living micro-organisms, a 1997 review in the European Journal of Oral Sciences explains. A 2002 review of calculus formation calls the supersaturation of saliva and plaque fluid with calcium phosphates the driving force for plaque mineralisation.
A 2018 review in Periodontology 2000 adds that mineralisation strengthens the attachment of the non-mineralised biofilm to the tooth surface, and that, from a clinical point of view, calculus always harbours a living, non-mineralised biofilm.
What is the difference between calculus above and below the gum?
Supragingival calculus forms above the gum line and subgingival calculus below it, and a 1997 review in the European Journal of Oral Sciences describes each.
In groups with regular oral hygiene and access to regular professional care, the review says, calculus above the gum is limited to tooth surfaces next to the salivary ducts, is minor and has little if any impact on oral health. In these groups, calculus below the gum occurs alongside gum disease, though the calculus itself appears to have little impact on loss of the gum's attachment to the tooth.
Without regular oral hygiene and without access to professional care, calculus above the gum occurs throughout the mouth and is associated with gum recession, and calculus below the gum is extensive and directly correlated with greater attachment loss. Whether calculus below the gum is a cause or a result of gum inflammation is not certain, the review says, but research suggests it may at least widen the area of damage that plaque causes.
The British Society of Periodontology's patient leaflet says tartar above the gum line can be removed by cleaning (scaling) the teeth and, where gum disease has destroyed some of the teeth's support, bacteria and calculus under the gum line by scaling and root debridement. Our page on deep cleaning for gum disease covers treatment below the gum line.
Questions about this treatment? Book online or call the practice.
How do disclosing tablets show plaque?
Disclosing tablets show plaque by staining it with a coloured dye, so you can check how well you have brushed, Great Ormond Street Hospital explains.
It advises chewing a tablet after brushing, then rinsing with water: the colour left on the teeth is plaque, which more brushing removes. Delivering Better Oral Health (DBOH) reports low to moderate certainty evidence that motivational methods involving plaque disclosure and repeated oral hygiene instruction reduce plaque, and very low to low certainty evidence that they reduce gingivitis.
Why does removing tartar at home fail?
Removing tartar at home fails because, the Oral Health Foundation says, tartar can only be removed by the dental team.
Calculus cannot be removed by brushing, the Leeds Teaching Hospitals NHS Trust gum disease leaflet states. Home care removes plaque before it hardens: our guides cover brushing along the gum line and cleaning between your teeth.
Does tartar-control toothpaste work?
Toothpastes containing pyrophosphates, zinc compounds and/or copolymers significantly reduced calculus scores against a placebo toothpaste in a 2004 systematic review of 32 reports.
A 2020 review in the Swiss Dental Journal notes that these additives do not reach the deeper parts of gum pockets, so they are recommended for inhibiting calculus formation above the gum line.
When should you speak to your dentist?
Show a dentist any hard deposit on your teeth that brushing does not remove. For gum and tooth symptoms, NHS guidance gives these actions; if you do not have a dentist or cannot get an emergency appointment, call 111 or visit 111 online:
- Gums that bleed when you brush your teeth or eat hard foods, gums that are painful and swollen, bad breath, or a child with sore, bleeding gums: see a dentist.
- Gum disease, in you or your child, with other symptoms such as very sore and swollen gums, teeth becoming loose or falling out, ulcers or red patches in your mouth, or a lump in your mouth or on your lip: ask for an urgent dentist appointment.
- Toothache that lasts more than 2 days, does not go away with painkillers, or comes with a high temperature, pain when you bite, red gums, a bad taste or a swollen cheek or jaw: see a dentist.
- Toothache with swelling around your eye or neck, or swelling in your mouth or neck that makes it difficult to breathe, swallow or speak: go to A&E, but do not drive; ask someone to drive you or call 999 and ask for an ambulance.
How much does gum care cost?
BPE screening, six-point charting, non-surgical periodontal therapy, desensitising treatment, halitosis assessment and advanced gum disease treatment have no line on the fee list. Nor do gum surgery and gum grafting.
Frequently asked questions
Does everyone get tartar?
Most adults do. Calculus above and below the gum occurs in the majority of adults worldwide, a 1997 review in the European Journal of Oral Sciences says. How much forms, and where, varies between populations and with factors such as oral hygiene habits, diet, age, time since the last dental cleaning and prescription medicines.
What is the difference between plaque and tartar?
Tartar, also called calculus, is plaque that has hardened. Plaque is a thin, sticky film of bacteria that constantly forms on your teeth, the Oral Health Foundation explains, and if brushing does not remove it, it can harden into tartar. Calculus cannot be removed by brushing, the Leeds Teaching Hospitals NHS Trust leaflet states.
What hygiene and gum care is available at Deepcar Dental Care?
Hygiene and gum care at Deepcar Dental Care includes BPE screening at every examination, full six-point periodontal charting, non-surgical periodontal therapy and desensitising treatment. It also includes a halitosis assessment. Treatment of advanced gum disease is done in house, as are gum surgery and gum grafting.
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Deepcar Dental Care is at 334 Manchester Road, Deepcar, Sheffield, S36 2RH, with free parking directly outside. Read about hygiene appointments, see patient reviews, or browse this section on prevention.
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Deepcar, Sheffield S36 2RH
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