48. Plaque Control

Question 1

UK oral hygeine market is worth … per annum

Answer 1

over 1 billion

Question 2

Oral care products

Answer 2

• varnishes (chlorhexidine, thymol)
• sprays
• chewing gums - xylitol
• fluoride containing products

Question 3

How have toothpastes developed?

Answer 3

• started as powders then pastes
• abrasives (silica, aluminium hydroxide)
• added fluoride from 1890s

Question 4

Ingredients of toothpastes

Answer 4

• surfactant (froth and foam)
• fluoride
• antibacterial agent (triclosan, metal salts, chlorhexidine, essential oils)
• flavours
• remineralizers (hydroxyapatite)
• random things like glycerol, sodium polyphosphate, diethylene glycol in China until 2007, arginine

Question 5

Arguments for mouthrinses

Answer 5

• plaque causes disease, contains microbes in numerous amounts that rapidly multiply
• eradication by mechanical means is near impossible
• use of chemical antimicrobials will reduce the oral load of microbes and alleviate disease

Question 6

Arguments against chemical mouthrinses

Answer 6

• adverse effects on microbial ecology of mouth
• lazy
• efficacy
• other measures like diet, fluoride toothpaste, good prophylaxis are more effective

Question 7

Explain the Plax case study

Answer 7

• original claim in late 1980s
• Colgate Plax - a pre-brush rinse which removes more plaque, combination of CPC and SLS, Bungay Scientific then Pfizer
• massive impact, claims not supported by clinical trials
• Pfizer subjected to class action suit in Alabama - has made misrepresentations concerning dental rinses Plax

Question 8

Antimicrobial chemicals used in UK

Answer 8

• iodine
• sanguinarine
• chlorhexidine
• hexetidine
• triclosan
• sodium Lauryl sulphate
• thymol
• cetylpyridinium chloride
• metal fluorides

Question 9

Phenolic mouthrinses

Answer 9

• Listerine
• Sainsbury’s Antiseptic Mouthwash with Fluoride
• and Sains Oral Health Extra
• Strength Antiseptic Mouthwash etc

Question 10

Define ‘substantivity’

Answer 10

persistance of antimicrobial activity on oral surface

Question 11

How does chlorhexidine work?

Answer 11

• bisbiguanide (cationic - attracted to negative charge)
• disrupts cell membrane phospholipids
• high substantivity - up to 12 hrs
• used in handwash in surgery and wipes

Question 12

Chlorhexidine acts against what?

Answer 12

• antibacterial against fungal infections
• reported antiviral activity
• broad spectrum - gram neg and pos
• bacteriostatic at low concs, bacteriocidal at higher

Question 13

How does chlorhexidine affect cell membranes?

Answer 13

• positively charged molecules interacts with negatively charged bacterial wall components
• destablises cell walls
• disrupts cell membranes
• disintegration of cell membranes
• cell lysis

Question 14

How should chlorhexidine be administered?

Answer 14

• 2x daily rinse with 0.2% solution
• plaque growth completely inhibited
• gingivitis inhibited
• efficacy confirmed in many studies
• 0.12% and 0.05% available (Eludril/Chlorohex)

Question 15

Problems with chlorhexidine

Answer 15

• tooth staining/iron salts
• taste
• allergy

Question 16

Triclosan is what chemical?

Answer 16

polychlorophenoxyphenol

Question 17

Properties of triclosan

Answer 17

• lower substansivity compared to CHX (co-polymer added)
• lipid soluble (penetrates skin and mucosa)
• antiphlogistic - reduces inflammation

Question 18

Targets of triclosan

Answer 18

• broad spectrum antimicrobial
• targets lipid synthesis/enoyl reductase
• inhibits glycolysis (lactate dehydrogenase/pyruvate kinase)
• inhibits H+-ATPase (cellular pH falls)

Question 19

Triclosan demonstrates efficacy against …

Answer 19

gingivitis

Question 20

Claims by Colgate regarding triclosan

Answer 20

• gingivitis occurs in the presence of plaque - mainly consisting of bacteria
• Triclosan is antibacterial and therefore has a beneficial effect on gingivitis
• strongly emphasizes it’s not a replacement for regular professional dental care

Question 21

How does hydrogen peroxide mouthwash work?

Answer 21

• an oxidising agent
• oxygenating action
• useful in managing necrotising gingivitis

Question 22

What is listerine made of and development?

Answer 22

• blend of essential oils with antiseptic properties
• used to be in 19th century as floor cleaner, took off in 1920s when Listerine invented halitosis

Question 23

What do the Medicines and Healthcare products Regulatory Agency do?

Answer 23

• regulates all medicines and medical devices in UK
• makes sure they’re safe and effective

Question 24

What do European Medicines Agency do?

Answer 24

• regulates medicines and medical devices
• efficacy of medicine requires evidence that works against a disease (e.g specific date on caries or periodontitis)

Question 25

What do the European Food Safety Authority do?

Answer 25

- regulate food supplements (includes additives to cosmetics such as on-fluoridated toothpastes) - requires efficacy in terms of function or disease risk reduction but NOT disease

Question 26

What do the Advertising Standards Authority say?

Answer 26

ensure adverts are 'responsible'

Question 27

What do the British Dental Association do?

Answer 27

Trade Union/lobbying organisation

Question 28

What do American Dental Association do?

Answer 28

a 'patient-centered, science based and ethically drivenv association'

Question 29

Which antiseptic is most effective in mouthrinses?

Answer 29

- chlorhexidine - essential oils - cetylpyridium chloride