Dental PlaqueWhat is Dental Plaque:-

Dental plaque is biofilm (usually colorless) that builds up on the teeth. If not removed regularly, it can lead to dental cavities (caries) or periodontal problems (such as gingivitis).

The microorganisms that form the biofilm are almost entirely bacteria (mainly Streptococcus mutans and anaerobes), with the composition varying by location in the mouth. Examples of such anaerobes include fusobacterium and Actinobacteria.h

The microorganisms present in dental plaque are all naturally present in the oral cavity, and are normally harmless. However, failure to remove plaque by regular

tooth brushing means that they are allowed to build up in a thick layer. Those microorganisms nearest the tooth surface convert to anaerobic respiration; it is in this

state they start to produce acids.

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Bacterial dental plaque

Acids released from dental plaque lead to demineralization of the adjacent tooth surface, and consequently to dental caries. Saliva is also unable to penetrate the build-up of plaque and thus cannot act to neutralize the acid produced by the bacteria and remineralize the tooth surface.

They also cause irritation of the gums around the teeth that could lead to gingivitis, periodontal disease and tooth loss.

Plaque build up can also become mineralized and form calculus (tartar).

What causes dental plaque on teeth:-

Dental plaque is comprised of colonies of bacteria and other microorganisms mixed with bacteria by-products, dead cells and food residuals.

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Tooth plaque formation starts immediately after a tooth is cleaned. The micro organisms of dental plaque are all naturally present in the oral cavity, and are normally harmless. Failure to remove dental plaque by regular toothbrushing allows its build up in a thick layer. As it matures, different types of micro organisms appear. At the lower layers of plaque, nearest the tooth surface, the composition of dental plaque changes in favour of anaerobic bacteria. Their anaerobic respiration is producing acids which consequently lead to:

demineralization of the adjacent tooth surface, and dental caries.

Irritation of the gums around the teeth (gum inflammation), leading to gingivitis

(red, swollen, bleeding gums), periodontal disease and tooth loss. Tooth plaque build up can also become mineralized and form calculus.

The main health problems of the oral cavity can be related to the accumulation of dental plaque on teeth.

Mechanism of Plaque Formation:-

The attachment, growth, removal and reattachment of bacteria to the tooth surface is a continuous and dynamic process. However, several distinct processes can be recognised:

1. Absorption of salivary proteins and glycoproteins, together with some bacterial molecules, to the tooth surface to form a conditioning film (the acquired pellicle).

2. Long-range (>5Onm), non-specific interaction of microbial cell surfaces with the acquired pellicle via van der Waals attractive forces.

3. Shorter-range (10-20nm) interactions, in which the interplay of van der Waals attraction forces and electrostatic repulsion produces a weak area of attraction that can result in reversible adhesion to the surface.

4. Irreversible adhesion can occur if specific inter-molecular interactions take place between adhesins on the cell surface and receptors in the acquired pellicle.

5. Secondary or late-colonisers attach to primary colonisers (coaggregation), also by specific inter-molecular interactions.

6. Cell division of the attached cells to produce confluent growth, and a bioflim.

What are the symptoms of plaque-associated gum disease:-

Mild gingivitis does not cause any symptoms and so you may not realise that you have it. The gums look slightly swollen and reddened.

Moderate gingivitis can cause more marked swelling and reddening of the gums. The gums often bleed a little when you clean your teeth. Discomfort or pain from the gums is rare if you only have gingivitis.

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Periodontitis often does not cause any symptoms until an affected tooth becomes loose. However, in some cases, symptoms develop and may include:

o halitosis (bad breath)o a foul taste in your moutho some pus formation in small pockets between teeth and gumso pain and difficulty eatingo Affected teeth becoming loose and eventually falling out if not

treated.

An examination by a dentist to detect the presence and depth of gum pockets is needed to confirm the diagnosis of periodontitis.

Factors can affect plaque formation:-

1) Oral hygiene.2) Orthodontic or prosthetic appliance as they may interfere with oral hygiene.3) Structure and position of the tooth. Roughness of enamel whether

development or acquired encourages plaque accumulation.4) Diet greatly affects plaque formation. Rough fibrous diet and the movement

of mastication reduce plaque, while a sucrose rich diet encourages plaque deposition through sticky polymers.

Dental calculus:-

Calculus is the hard residue ranging from yellow to brown forming on teeth when oral hygiene is incomplete or improper. Calculus is formed from Plaque (a soft sticky substance that accumulates on teeth; composed largely of bacteria and food substances suspended in saliva) which can build up and become hard. This hard plaque is known as tartar or calculus. Brushing and flossing alone cannot remove calculus. A dentist or hygienist must remove it manually to stop the disease process.

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Although plaque and calculus have different characteristics a relationship exists between them. It is the host to a complex micro-system of microorganisms that cause inflammatory diseases of the gingival & periodontal tissues. Plaque can be removed from tooth surfaces by direct brushing. It is possible to have a mouth with plaque but no calculus. Calculus is formed by the deposition of mineral salts in plaque. It is hard and firmly adherent to the tooth surfaces on which it forms and it cannot be removed by brushing. Calculus acts as a focal point for plaque accumulation bacteria and hinders complete removal of plaque. Both plaque and calculus play an important role in gum disease. As gums ”pull away” from the teeth as a result of gum-disease pockets begin to form between the teeth and gums. Plaque and calculus fill these pockets until eventually the jawbone supporting the teeth are destroyed. Calculus deposits can be classified as s light moderate or heavy.

Calculus forms in various areas of the mouth. The terms Supra-gingival calculus and subgingival calculus are given to the most common areas of calculus build up.

Supra-gingival calculus is found on the tooth surface next to the tongue (lingual) on the mandibular incisors and on the buccal surfaces (area near the cheek) of maxillary molars. Subgingival calculus forms on root surfaces below the gingival margin and can extend deep into periodontal pockets. A more irregular subgingival cemental surface allows deposits to form into the cemental irregularities. This makes the attachment of the subgingiva calculus more tenacious and difficult to remove. Subgingival calculus can often be seen on radiographs but explorer detection is needed to evaluate the amount of calculus present.

Rate of calculus formation varies from person to person but the following can certain factors can increase the rate of calculus formation. These factors are Elevated salivary PH.

· Elevated salivary calcium concentration.

· Elevated bacterial protein and lipid concentration.

· Elevated concentration of protein and urea in submandibular salivary gland secretions.

· Low individual inhibitory factors.

· Higher total salivary lipid levels.

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Treatments to remove or prevent calculus

Build up are numerous and include surgical and non-surgical procedures. A surgical approach is when full thickness tissue flaps are reflected to expose the root surfaces and gain direct access to them. A non-surgical approach is when access to the root surfaces is via the periodontal pockets.

The efficacy of subgingival plaque and calculus removal utilizing a non-surgical approach is limited.

Procedures to remove calculus include the following:-

· Scaling:

The meticulous removal from the root surfaces of the teeth to remove plaque calculus and stains from these surfaces.

· Root Planing:

A treatment procedure designed to remove cementum or surface dentin that is rough impregnated with calculus or contaminated with toxins or microorganisms.

· Periodontal Debridement:

This includes the removal of plaque and calculus both above and below the gingiva.

· Prophy / Prophylaxis:

A preventive procedure to remove local irritants to the gingiva including debridements of calculus and removal of plaque.

How can I prevent plaque-associated gum disease:-

Good oral hygiene (mouth hygiene) helps to keep plaque down and usually prevents gum disease. (Good oral hygiene also helps to prevent tooth decay.) Good oral hygiene means:

Brush your teeth - for two minutes, at least twice a day. Studies show that powered toothbrushes with a rotation-oscillation action (where the brush rapidly changes direction of rotation) remove plaque and debris better than manual brushes.

Floss your teeth at least three times a week to remove plaque from between teeth.

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Also:

See a dentist or dental hygienist for advice if you cannot use a toothbrush. Children should be taught good oral hygiene as young as possible. Have regular dental checks. A dentist can detect excessive build up of plaque

and remove calculus. Early or mild gingivitis can be detected and treated to prevent the more severe periodontitis.

If you smoke, you should aim to stop smoking.

The measures above are usually sufficient. However, many people also use an antiseptic mouthwash each day to help prevent gum disease.

What is the treatment of plaque-associated gum disease:-

If you have gingivitis:

The measures described above to prevent gum disease will often clear mild gingivitis. If gingivitis is more severe, in addition your dentist or doctor may advise an antiseptic mouthwash (and/or antiseptic toothpaste, gel, or spray). These help to kill bacteria in the mouth and help to clear up any gum infection.

Chlorhexidine is a commonly used antiseptic mouthwash. If you are advised to use chlorhexidine, you should rinse your mouth well with water between brushing your teeth and using chlorhexidine. This is because some ingredients in toothpaste can inactivate chlorhexidine. Chlorhexidine may also stain teeth brown when used regularly. This staining is likely to need to be removed by a dentist or dental hygienist. Staining can be reduced by:

Brushing teeth before (but not after) using the chlorhexidine. Avoiding drinks that contain tannin within 2-3 hours of using chlorhexidine

(for example, tea, coffee, and red wine). Using the 1.2% solution instead of higher strength solutions.

If you have periodontitis:

You should see a dentist. In addition to the measures described above to treat gingivitis you may need specialist dental treatment. Various procedures may be done, depending on the severity of the condition and other factors. For example, in one procedure a dentist may clean a 'pocket' next to a tooth where infection is present. Following this, a dentist may smooth out the surface of the tooth next to the gum. This helps the gum to close back onto the tooth, and for any 'pocket' to disappear.

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Control of dental plaque:-

1. Oral hygiene.2. Diet: Plaque increase considerably in the presence of carbohydrates,

especially sucrose. Limiting dietary carbohydrates has a dramatic effect on plaque volume.

3. Physical removal of plaque: e.g. tooth brushing, use of dental floss and interdental wooden wedges.

4. Ultrasonic scaling devices: A) These remove plaque and calculus mechanically. B) Ultrasonic vibration disturbs bacteria in sub gingival plaque.

5. Antiseptics: chloromexidine and providine-iodine reduce bacteria. Its action may extend for some time.

I Hope you Healthy teeth

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References http://en.wikipedia.org/wiki/Dental_plaque http://users.forthnet.gr/ath/abyss/

dep1211.htm http://images.google.com.eg/images?

hl=ar&q=dental+plaque&um=1&ie=UTF-8&ei=V9TVSaXzK8WNjAfJjoH4Dg&sa=X&o

http://www.dentistry.leeds.ac.uk/OROFACE/PAGES/micro/micro2.html

http://www.dentalfind.com/glossary/calculus.html

http://www.privatehealth.co.uk/diseases/infections/dental-plaque-and-gum-disease/

The main reference isMedical microbiology and immunology book

By

DR. Salwa E. youssef.

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