All about toothpaste and its ingredients

 

Everybody's mouth is like a private ''zoo'' which contains one or more of many types of microorganisms. Among these organisms, especially  Streptococcus mutans, some create sticky plaque from food residue in the mouth. There, in the mouth, microorganisms feed on leftover food to make acid and volatile sulphur molecules. The volatile sulphur molecules give breath its foul odour while the acid eats into tooth enamel to create cavities.

Toothpaste works together with tooth brushing to clean teeth and remove the plaque and bacteria. Toothpastes can be defined as mild cosmetic detergents for cleaning teeth. Also known as dentifrices, toothpastes have chemical compounds that clean and polish the user's teeth. Dentifrices come in three forms namely, liquid, powder and paste. Pastes are the most popular of the three.

We are familiar with many brands of toothpastes. Examples are Colgate, Enamel Saver, Tom's of Maine, Mentadent, Crest, Aquafresh Whitening, AIM and Closeup. What are they made of? 

The five main ingredients of toothpastes are mild soap, abrasive, active ingredient,

humectant and flavour. Some other ingredients are added such as water, thickeners, colouring agents, sweeteners and preservatives.

The mild soap or detergent makes the toothpaste to foam thereby preventing the toothpaste from dribbling out as one brushes. The most commonly used detergent in toothpaste is sodium lauryl sulphate(SLS). Other detergents that can be used include ammonium cocoyl isethionate, sodium dodecyl benzene sulphonate and poloxamer.

Abrasives remove stains and plaque, as well as polish teeth. A good abrasive will not scratch the tooth enamel and yet will exert sufficient scouring action to clean and polish teeth. It should not react with the other ingredients, spoil the taste or appearance of the toothpaste nor segregate or lump with aging. Good and commonly used abrasives in toothpastes are hydrated silica and calcium carbonate. Others are kaolin, talc, magnesium carbonate, calcium phosphate, tin oxide and bentonite. Any abrasive that is to be used should be very finely ground. Abrasiveness of a toothpaste is measured by its Relative Dentin Abrasivity (RDA). Let’s not go into details on this and talk about humectants.

Humectant gives toothpaste its texture and retains moisture to prevent the toothpaste from drying out. Common humectants used in toothpastes are sorbitol, glycerin and water. Xylitol is an uncommon but superior humectant which also enhances cavity fighting and hence, also used as an active ingredient.. The proportion of humectants in toothpastes can vary from 5-10% to as high as 30% or more. Low proportions of humectants are not recommended.

The active Ingredients used in making toothpastes include fluoride, triclosan, anti-tartar agents, desensitizing agents, sodium bicarbonate (baking soda), xylitol, enzymes and extracts from ginger and seaweed. Fluoride strengthens teeth and prevents cavities. It is a very important ingredient in toothpaste. In toothpastes, the source of fluoride can be sodium monofluorophosphate, sodium fluoride or stannous fluoride. It is important to note that sodium fluoride is not compatible with calcium carbonate. Therefore, if you want to make toothpaste using CaCO₃ as abrasive, you can use sodium monofluorophosphate instead of sodium fluoride as a source of fluoride. Triclosan is used to control plaque while sodium bicarconate gives the sensation of a cleaner mouth. Enzymes enhance the antibacterial properties of saliva. Xylitol, a non-sugar sweetener, have three functions in toothpaste namely sweetener, humectant and active ingredient. It reduces levels of decay causing bacteria in the mouth and enhances remineralization.

Flavouring agents are added in toothpastes to improve the taste. They cover up the bad taste of most detergents like sodium lauryl sulphate. Peppermint and spearmint are common toothpaste flavours.

Sweeteners also improve the taste of toothpaste. Most of them are artificial and contribute very little to cavity formation. An example is saccharin which is commonly used.

Thickeners help to create the texture of toothpaste and also determine its thickness. Carrageenan, xanthan gum and cellulose gum are common thickening agents.

Preservative helps to prevent deterioration of toothpaste by inhibiting the growth of microorganisms in toothpaste. Common examples are sodium benzoate, methyl paraben and ethyl paraben.

Finally, let’s talk about colouring agents. These provide toothpaste with pleasing colours. Artificial dyes are used to make green, blue and red toothpastes. Titanium dioxide is used to make white toothpastes.