Drugs to prevent caries, plaque, and gingivitis

Question 1

Tooth enamel is made up of mostly what?

Answer 1

More or less hydroxyapatite

Question 2

What is dissolved in saliva and sometimes adds back to enamel?

Answer 2

Ca+2

PO4-3

Question 3

What is the interaction of PO4 and acid?

Answer 3

PO4 is a base, and the pH will affect the distribution of it’s ionic forms

Question 4

Acid induced demineralization

Answer 4

The lower the pH, the less PO4-3 will be available

Thus, the acidic environment will lead to more removal of (Ca+2)3(PO4-3)2 from enamel

Question 5

What is the “critical pH”?

Answer 5

5.5
Above, teeth will remineralize
Below, teeth will lose minerals

Question 6

What drugs can prevent caries

Answer 6

Fluoride

Question 7

If all of the hydroxide in a tooth was replaced with fluoride, you would have a tooth with what?

Answer 7

Smaller crystals
Better H bonding within the crystal
Decreased solubility

Question 8

What does a ‘fluoridated tooth’ have?

Answer 8

A little Fluorohydroxyapitite

A lot of Hydroxyaptite

Question 9

What does fluoride inhibit?

Answer 9

Enolase

Question 10

Substitution of some of the hydroyls in the HA lattice of tooth enamel with fluoride increases what? By what mechanism?

Answer 10

Increases the resistance of the enamel to demineralization under mildly acidic conditions
Satisfactory explanation for this effect have not yet been provided

Question 11

Dental plaque

Answer 11

A biofilm or mass of bacteria that grows on surfaces within the mouth
Commonly associated with oral diseases such as caries and perio disease
Formation is a normal process that cannot be prevented

Question 12

Facultative anaerobe

Answer 12

Organism that make ATP by aerobic respiration if oxygen is present, but is capable of swiching to fermentation under or anaerobic respiration if oxygen is absent

Question 13

What can be found in healthy gums

Answer 13

Gram+ microbes

Facultative anaerobes

Question 14

What can be found in unhealthy gums

Answer 14

Gran- microbes

Obligate anaerobes

Question 15

Absorption in the mouth

Answer 15

Vascular and thin epithelium allows drugs to be well absorbed
This is great for drugs like nitroglycerin, but not so great if you want drugs to act in the mouth and no where else
Drugs tend to be highly ionized for this reason

Question 16

Oral cavity distribution

Answer 16

The ability of oral agents to bind reversibly to oral reservoirs is an important quality for sustained release oral drugs

Question 17

Salivary flow is a major determinant of what?

Answer 17

The duration that a drug remains in contact with the surface of the tooth

Question 18

Substantivity

Answer 18

The time a drug is in contact with a particular substrate in the oral cavity
Reflects reversible binding to oral reservoirs and rate of clearance by salivary flow

Question 19

What are properties of good antiplaque and anti-gingivitis agents?

Answer 19

Safe
Efficacious
Speficic
No induced drug resistance
Good/acceptable taste
Low cost

Question 20

What are some anti-plaque and anti-gingivitis agents?

Answer 20

Bis-biguanised
Non-ionic bisphenols
Phenolic compounds
Quaternary ammonium compounds
Morpholino compounds

Question 21

What are examples of Bis-biguanides?

Answer 21

Chlorohexidine

Alexidine

Question 22

How does Chlorohexidine work?

Answer 22

Ruptures bacterial cell membranes, leading to leakage of contents and death
Binds salivary mucins, reducing pellicle formation, which in turn inhibits bacterial colonization
Binds bacteria, inhibiting absorption onto the teeth

Question 23

What might be a indication for chlorohexidine?

Answer 23

Gingivitis
Periodontitis
Dental traumas
Oral cysts
Post wisdom tooth extractions

Question 24

Low doses of chlorohexidine are what?

Answer 24

Bacteriostatic

Question 25

High doses of chlorohexidine are what?

Answer 25

Bacteriocidal

Question 26

Chlorohexidine acts on what type of bacteria

Answer 26

Both gram+ and gram-

Question 27

What is an example of non-ionic bisphenol?

Answer 27

Triclosan

Question 28

High concentrations of triclosan act as what?

Answer 28

Biocide with multiple cytoplasmic and membrane targets

Question 29

Lower concentrations of triclosan are what?

Answer 29

Bacterostatic; targeting bacteria primarily by inhibiting fatty acid synthesis

Question 30

Triclosan theraputics in toothpaste and mouth rinses

Answer 30

Moderal plaque-inhibitory action and antimicrobial substantivity of around 5 hours

Question 31

Phenolic compunds

Answer 31

Phenol, thymol, chlorothymol, hexylresorcinal
In many mouth rinses
Probably has more of an effect on gingivitis than on plaque formation (anti-inflammatory?)

Question 32

Quaternary ammonium compound example

Answer 32

Cetylpyridinium chloride (CPC)

Question 33

Cetylpyridinium chloride (CPC)

Answer 33

Catatonic quaternary ammonium compound used in some types of mouth rinses, toothpastes, lozenges, throat sprays, breath sprays and nasal sprays
Antiseptic that kills bacteria and other microorganisms
Shown to be effective in preventing dental plaque and reducing gingivitis
May cause brown staining, but they’re easily removed during prophys

Question 34

Morpholinos

Answer 34

Cationic surfactant

Keeps bacteria from attaching to tooth surface