The agents, which are used in the prevention of caries, polishing agents and desensitizing agents, called dental products.
A wide variety of inorganic compounds used in dentistry are of interest to pharmacists. These include-
1. Polishing
2. Cleaning
3. Anticaries agents
Anticaries agents (Fluorides)
Products of fluorides are-
1. Fluoridated water
2. Fluoride drops
3. Topical fluoride application to teeth
4. Fluoride-containing vitamins
5. Fluoride dentifrices
Problems associated with antibiotic-containing dentifrices
1. Sensitization of a significant portion of the population to the antibiotic and
2. Development of antibiotic-resistant microorganisms. Chemical composition of dentifrice-
CH3¾NCH2CO2Na
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C(CH2)10CH3
||
O
Sodium N-lauroyl sarcosinate
The mechanism by which fluoride inhibits caries formation
The mechanism by which fluoride inhibits caries formation is still to be completely elucidated. There are two current hypotheses:
1. Decreased acid solubility of enamel and
2. Bacterial inhibition
Decreased acid solubility of enamel
We came to know that fluoride decreases the solubility of enamel in acid. This lowering of solubility is more pronounced in enamel already attacked by caries. Caries lesions cause the enamel to become more permeable to fluoride which, along with the lower pH found in a caries lesion, favors fluoride uptake by hydroxyapatite. Enamel already showing carious changes may be 20% less soluble than intact enamel in the same teeth. Even if one assumes that fluorapatite is less soluble than hydroxyl apatite, the outer enamel will have at the most only one hydroxyl in 50 replaced by fluoride, which would not affect the overall decrease in observed solubility. Other mechanisms that have been postulated as to how fluoride might decrease enamel solubility include:
(1) Reduction of the number of defects in apatite crystals; and
(2) Competition with carbonate during apatite formation
Bacterial inhibition
This hypothesis is based on the enzyme inhibitory properties of fluoride. This in itself is difficult to justify, as a fluoride concentration of 10 ppm is needed for any significant inhibition of many of the oral bacteria. Though plaque fluoride is bound fluoride, it still seems to reduce acid production in the plaque. In contrast, topically applied sodium fluoride loses its ability to inhibit acidogenesis within one week of application indicating that fluoride reduces the incidence of caries by some other mechanism. While it might appear that the fluoridated plaque is beneficial. Its presence still promotes inflammation of the gingivae (gums), making its removal desirable.
Mechanisms of fluoride decrease enamel solubility include:
(1) Reduction of the number of defects in apatite crystals; and
(2) Competition with carbonate during apatite formation
Adjusted allowance of fluoride
| Water fluoride (ppm) | Sodium fluoride (mg per day) | Provide fluoride ion (mg per day) |
| 0.0 | 2.2 | 1.0 |
| 0.2 | 1.8 | 0.8 |
| 0.4 | 1.3 | 0.6 |
| 0.6 | 0.9 | 0.4 |
Stability of stannous fluoride solution
1. The stability is increased with increasing stannous fluoride concentration.
2. The rate of turbidity formation is temperature-dependent.
3. The loss of stannous cation is both pH-dependent and dependent upon the buffer or complexing agent used.
Official products
Sodium fluoride
Sodium fluoride (NaF) U. S. P. is a compound having molecular weight 41.99.
Properties
1. It is a white odorless powder
2. It is soluble in water and insoluble in alcohol.
Application
1.5 to 3 ppm in drinking water; topically, as a 2% solution to the teeth
Usual dose: 2.2 mg once a day
Stannous Fluoride (SnF3)
It is a topical product having mol. wt. 156.69.
Properties
1. It is a white, crystalline powder.
2. It has a bitter, salty taste.
3. It melts at about 2130 C.
4. It is freely soluble in water and is practically insoluble in alcohol, ether and chloroform.
Use: It has topical use only.
Phosphate
Dentifrices
1. Anticaries agents
2. Polishing agents
3. Thickening agents
4. Surfactants
5. Humectants
Composition of Crest, a stannous fluoride tooth paste
| Chemical Constituents | Amount (%) |
| Stannous fluoride | 0.4 |
| Stannous pyrophosphate | 1 |
| Calcium pyrophosphate | 39 |
| Glycerin | 10 |
| Sorbitol (70% solution) | 20 |
| Water | 29.6 |
| Miscellaneous formulating agents | |
Composition of Colgate, an MFP fluoride tooth paste
| Chemical Constituents | Amount (%) |
| Sodium monofluorophosphate (MFP) | 0.76 |
| Insoluble sodium metaphosphate | 41.85 |
| Anhydrous dicalcium phosphate (CaHPO4) | 5 |
| Sorbitol | 11.9 |
| Glycerol | 9.9 |
| Sodium N-lauroyl sarcosinate | 2 |
| Water | 24.4 |
| Miscellaneous formulating agents | 4.2 |
Test of degree of abrasiveness
In vitro test
1. Brushing machines that evaluated wear on a tooth surface
2. Loss of tooth surface as measured by radiotracer techniques
3. Enamel-polishing capability as measured by a reflectometer
In vivo test
1. Measuring the degree of stain buildup or removal over a period of time
2. The degree of abrasiveness on acrylic surfaces of veneer crowns
Cleaning agents
Some common cleaning agents are as follows.
1. Insoluble Sodium metaphosphate (NaPO3)
2. Anhydrous and hydrous calcium monohydrogen phosphate (dicalcium phosphate; CaHPO4 and CaHPO4.2H2O)
3. Calcium pyrophosphate (Ca2P2O7)
4. Calcium carbonate (CaCO3)
5. Pumice
Cosmetic dentifrices
| Brand | Composition | Abrasivity |
| Close Up | Silicas of controlled particle size | Moderate |
| Excitement | CaHPO2. 2H2O | Low |
| Macleans | CaHPO4. 2H2O | Moderate |
| Pearl Drops Tooth Polish | Hydrated AlPO4 and CaHPO4. 2H2O | Moderate |
| Plus White | CaHPO4 and CaHPO4. 2H2O | Moderate to high |
| Plus White Plus | CaHPO4 and CaHPO4. 2H2O | Moderate to high |
| Ultra Brite | CaHPO4 and CaHPO4. 2H2O | Moderate |
| Vote | Silica | Moderate to high |
Official product
Pumice
Pumice is a substance of volcanic origin, consisting chiefly of complex silicates of aluminum, potassium and sodium.
Properties
1. It occurs as very light, hard, rough, porous, grayish masses, or as a gritty, grayish powder.
2. It is odorless and tasteless, and stable in air.
3. It is practically insoluble in water, and is not attacked by acids.
Desensitizing agents
1. Sensodyne (contains strontium chloride)
2. Thermodent (contains formalin)
3. Ammoniacal Silver Nitrate Solution
Official products
Zinc Chloride
Zinc Chloride U.S.P. is an astringent and dentin desensitizer. It is topical to the teeth as a 10% solution; to the skin and mucous membranes, as a 0.5% to 2% solution.
Properties
1. It is a white or practically white, odorless, crystalline powder or white or practically white crystalline granules.
2. It may also have porcelain-like masses or be molded into cylinders.
3. A 1 in 10 solution is acid to litmus.
4. It is very soluble in water and freely soluble in alcohol and glycerin.
5. Its solution in water or in alcohol is usually slightly turbid, but it is disappeared after adding a small quantity of hydrochloric acid.
Zinc-Eugenol Cement
Zinc-Eugenol Cement N.F. consists of some powders (zinc acetate, zinc stearate, zinc oxide, rosin); and liquids (Eugenol and cottonseed oil).
Property
To use the cement, a thick paste is prepared immediately before use by mixing up ten parts of the powder with one part of the liquid.
Use
It is widely used by dentists for their sedative effect on pulpal pain, particularly when restoring teeth with deep carious lesions.
