Plaque control Flashcards
Why do we need to control plaque?
Fundamental in control of gingivitis and health maintenance
We can control plaque using mechanical removal techniques – flossing and brushing
Or we can use professional prophylactic antimicrobials (dentist)
Why do we use flouride to control plaque formation
Fluoride in water supply reduces caries
1 ppm is optimum
Mode of action is still debated:
Favourably influences remineralisation of enamel
Fluoride can also inhibit the metabolism of some plaque bacteria
Fluoride can be given as a supplement and in mouthwashes and as a gel.
High concentrations are used to treat xerstomic patients and some disabled people
Why do we use antimicrobials within tooth care products
Most people cannot maintain oral health using mechanical methods
Antimicrobials are therefore formulated into oral health care products
There is only a short contact time in the mouth between the product and the teeth so it is essential for the agent to bind to the oral mucosa
This is called hanging around ability is called substantivity
Why do we need substancitvity in our oral heathcare products
This allows the reduction of microbial growth for prolonged periods of time even at sub-lethal levels
Once the agents are adsorbed to the mouth they are released slowly back into the oral environment
They are then re-distributed around the mouth.
What does chlorhexidine (Bisbiguanide) do theraputically
Its a broad spectrum antimicrobial agent
Reduces plaque, caries and gingivitis
Long term use can cause staining and mucosal irritation
Substantive – binds to surfaces well
Mutans streptococci are highly sensitive
Cannot be formulated into a toothpaste (mouthwash/gel/varnish only)
When do we use triclosan
Most commonly used agent in toothpaste
Its broad spectrum phenol and selectively inhibits obligately anaerobic gram negative bacteria (most associated with gingivitis)
What is the mode of action of triclosan
It has multiple modes of action
Inhibits acid production from sugars, reduces inflammation in the host, inhibits bacterial fatty acid metabolism
Has good substantivity and can be enhanced by formulation with a co-polymer or zinc citrate
Concerns over widespread use - it has been found in areas of the environment it shouldn’t be (breastmilk, fish, water supplies etc.)
Which products are formulated with triclosan
Its not found in mouthwash. No longer found in colgate total any more after the issues with it enetring the environment. Found in unilever toothpaste
Why do we include enzymes and essential oils into tooth care products
Dextranases and glucanases to modify plaque matrix
Glucose oxidase and amyloglucosidase to boost salivary peroxidase system
Menthol, thymol and eucalyptol can penetrate plaque
Oils disrupt cell membranes and inhibit enzymes
Plant extracts – recently fashionable
What are Quaternary Ammonium Compounds (QACs) and give an example
A common oral hygiene example is Cetyl-pyridium chloride
Broad spectrum
Substantive (cationic)
Binds to bacterial cell membranes and disrupts integrity
Inhibits glucan synthesis and co-aggregation
Formulation – mouthwash only (not toothpaste)
Why do we include metal ions into dental formulations
We usually include zinc or stannous salts
Zinc salts inhibit bacterial glycolysis
May be synergistic (formulated together) with other antimicrobials
Zinc lactate inhibits volatile sulphur compound production (causes bad breath)
Stannous fluoride inhibits caries formation
Reduces dental hypersensitivity (larger tubules that result in sensitivity)
Why do we add surfactants into our dental formulations
To create foams to give the illusion of cleaner teeth.
Most common one is Sodium Lauryl Sulphate (SLS) which has detergent properties – disrupts lipids in the bacterial cell (no more cell integrity)
After debris removed from teeth it enters the brushing solution – interaction with SLS forms micelles which prevents anything being redeposited
Bactericidal – inactivates bacterial enzymes
Formulation issues with enzymes (detergents prevent enzymes from working)
Foams to coat the teeth and removes organic matter to bulk phase
Some people may be allergic
Why do we include arginine in dental formulations
Critical pH for caries is about 5.5. Arginine salts increase the pH
Arginine is metabolised by bacteria to ammonia containing end-products
This raises the pH in the mouth, keeping it above critical caries levels
Arginine additionaly is a sensitivity agent (blocks dental tubules)
Why don’t sweetners cause caries
Dietary sweeteners proposed to prevent caries
No acid challenge
Examples include aspartame and saccharin
Not metabolised by plaque bacteria
Sorbitol, mannitol and lactitol in sugar free chewing gums - enhansed effects of increasing saliva production
Whats the future of oral hygiene products
Oral probiotics - taking harmless bacteria to modulate existing microbiota in the mouth
Potential for life-long protection - difficult to overcome colonisation resistance of original microbiota
Popular with consumers
Safety concerns? Poor quality control (not regulated as medicines)
Examples include non pathogenic mutans streptococci
