Drugs to prevent caries, plaque, and gingivitis Flashcards
Tooth enamel is made up of mostly what?
More or less hydroxyapatite
What is dissolved in saliva and sometimes adds back to enamel?
Ca+2
PO4-3
What is the interaction of PO4 and acid?
PO4 is a base, and the pH will affect the distribution of it’s ionic forms
Acid induced demineralization
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
What is the “critical pH”?
5.5
Above, teeth will remineralize
Below, teeth will lose minerals
What drugs can prevent caries
Fluoride
If all of the hydroxide in a tooth was replaced with fluoride, you would have a tooth with what?
Smaller crystals
Better H bonding within the crystal
Decreased solubility
What does a ‘fluoridated tooth’ have?
A little Fluorohydroxyapitite
A lot of Hydroxyaptite
What does fluoride inhibit?
Enolase
Substitution of some of the hydroyls in the HA lattice of tooth enamel with fluoride increases what? By what mechanism?
Increases the resistance of the enamel to demineralization under mildly acidic conditions
Satisfactory explanation for this effect have not yet been provided
Dental plaque
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
Facultative anaerobe
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
What can be found in healthy gums
Gram+ microbes
Facultative anaerobes
What can be found in unhealthy gums
Gran- microbes
Obligate anaerobes
Absorption in the mouth
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
Oral cavity distribution
The ability of oral agents to bind reversibly to oral reservoirs is an important quality for sustained release oral drugs
Salivary flow is a major determinant of what?
The duration that a drug remains in contact with the surface of the tooth
Substantivity
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
What are properties of good antiplaque and anti-gingivitis agents?
Safe Efficacious Speficic No induced drug resistance Good/acceptable taste Low cost
What are some anti-plaque and anti-gingivitis agents?
Bis-biguanised Non-ionic bisphenols Phenolic compounds Quaternary ammonium compounds Morpholino compounds
What are examples of Bis-biguanides?
Chlorohexidine
Alexidine
How does Chlorohexidine work?
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
What might be a indication for chlorohexidine?
Gingivitis Periodontitis Dental traumas Oral cysts Post wisdom tooth extractions
Low doses of chlorohexidine are what?
Bacteriostatic
High doses of chlorohexidine are what?
Bacteriocidal
Chlorohexidine acts on what type of bacteria
Both gram+ and gram-
What is an example of non-ionic bisphenol?
Triclosan
High concentrations of triclosan act as what?
Biocide with multiple cytoplasmic and membrane targets
Lower concentrations of triclosan are what?
Bacterostatic; targeting bacteria primarily by inhibiting fatty acid synthesis
Triclosan theraputics in toothpaste and mouth rinses
Moderal plaque-inhibitory action and antimicrobial substantivity of around 5 hours
Phenolic compunds
Phenol, thymol, chlorothymol, hexylresorcinal
In many mouth rinses
Probably has more of an effect on gingivitis than on plaque formation (anti-inflammatory?)
Quaternary ammonium compound example
Cetylpyridinium chloride (CPC)
Cetylpyridinium chloride (CPC)
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
Morpholinos
Cationic surfactant
Keeps bacteria from attaching to tooth surface
