Oral Care Ingredients Glossary
Understanding what goes into your toothpaste and mouthwash helps you make informed choices about the products you use every day. This glossary covers the most common — and some not-so-common — ingredients found in oral care products, from active compounds like fluoride and hydroxyapatite to preservatives, surfactants, and natural extracts.
Click any letter to jump to that section, or scroll through to explore all 33 ingredients. Each entry explains what the ingredient is, what it does, and what you should know as a consumer.
A
Activated Charcoal
Also known as: Activated carbon, activated charcoal powder
What it is
Activated charcoal is charcoal that has been processed at high temperatures to create an extremely porous structure with a very large surface area. This porosity gives it strong adsorptive properties — it can bind to certain substances on contact. It has established medical uses, such as treating some cases of poisoning.
What it does in oral care
In oral care, activated charcoal products are marketed as helping to remove surface stains through adsorption. Some users also report a brightening effect, though this should be distinguished from regulated whitening treatments. It creates a distinctive black paste or powder when used.
What to know
Activated charcoal toothpaste is a controversial ingredient among dentists. Concerns exist that the abrasiveness of charcoal particles may wear down enamel over time, and most charcoal toothpastes do not contain fluoride. The evidence supporting surface stain removal claims for activated charcoal is limited compared to the evidence base for other oral care abrasives and peroxide-based products. If you choose to use it, occasional use rather than daily brushing is generally recommended.
Found in: Natural and detox-style toothpastes, whitening powders, charcoal toothpaste formulas
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Aloe Vera
Also known as: Aloe barbadensis miller, aloe gel
What it is
Aloe vera is a succulent plant whose inner gel has been used in traditional medicine for centuries for its soothing and anti-inflammatory properties. In oral care, the clear gel extracted from the plant's leaves is incorporated into toothpastes and mouthwashes.
What it does in oral care
Aloe vera is used in aloe vera toothpaste primarily for its soothing effect on gum tissue. It contains anthraquinones and polysaccharides that some research suggests may have anti-inflammatory and mild antimicrobial activity. It has a soothing reputation and is a popular choice in natural oral care formulas designed for everyday use with sensitive mouths.
What to know
Aloe vera is well-tolerated by most people and considered gentle enough for those with sensitive gums or oral tissue. It is typically used as a supporting ingredient rather than the primary active agent. Products containing aloe vera are generally suitable for everyday use and are found across both natural and mainstream oral care ranges.
Found in: Natural toothpastes, sensitive toothpastes, herbal mouthwashes, gum health products
Link to this termB
Benzalkonium Chloride
Also known as: BAC, BAK, alkyldimethylbenzylammonium chloride, ADBAC
What it is
Benzalkonium chloride is a quaternary ammonium compound used as a broad-spectrum antiseptic and surfactant. It has been used in medical, household, and personal care products for decades, and is also found in some eye drops and nasal sprays.
What it does in oral care
In oral care, benzalkonium chloride acts as an antimicrobial agent, killing or inhibiting the growth of bacteria and fungi in the mouth. It is included in some mouthwashes and toothpastes to help reduce plaque bacteria, support gum health, and freshen breath.
What to know
Benzalkonium chloride is approved for use in oral care products at low concentrations. There has been some research into potential irritancy effects at higher concentrations, particularly in nasal and ophthalmic products, but at the low concentrations used in oral care products, it is considered acceptable by the TGA and is assessed as safe at permitted levels by the European Scientific Committee on Consumer Safety (SCCS). Those with known sensitivity to quaternary ammonium compounds may wish to choose products without it.
Found in: Some mouthwashes, medicated toothpastes, oral antiseptic rinses
Link to this termC
Calcium Carbonate
Also known as: Chalk, precipitated calcium carbonate, CaCO₃
What it is
Calcium carbonate is a naturally occurring mineral compound that is the main component of limestone, chalk, and marble. In its pharmaceutical grade form it is also used as a dietary calcium supplement and antacid. It is one of the oldest and most widely used abrasives in toothpaste.
What it does in oral care
As a toothpaste abrasive, calcium carbonate physically scrubs away plaque, food debris, and surface stains from tooth enamel during brushing. It also acts as a mild polishing agent, leaving teeth feeling smooth. Because it is made of calcium — a key mineral in tooth structure — it is regarded as a tooth-compatible abrasive.
What to know
Calcium carbonate has a low-to-moderate RDA (relative dentine abrasivity) rating, meaning it is generally considered safe for daily use at typical toothpaste concentrations. It is a common ingredient in natural toothpastes as a fluoride-free alternative abrasive.
Found in: Natural toothpastes, everyday cleaning toothpastes, children's toothpastes, polishing toothpastes
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Carrageenan
Also known as: E407, Irish moss extract, kappa-carrageenan
What it is
Carrageenan is a natural polysaccharide (a type of carbohydrate) extracted from red seaweed. It has been used as a thickener, gelling agent, and stabiliser in food and personal care products for decades. In toothpaste, it is used to create and maintain the smooth, gel-like texture of the product.
What it does in oral care
Carrageenan acts as a binder and thickener in toothpaste, helping to hold the formula together and prevent the liquid and solid components from separating. It contributes to the smooth, consistent texture consumers expect when squeezing toothpaste from a tube. Without binders like carrageenan, toothpaste would be grainy or prone to separation.
What to know
Some consumer health advocates have raised concerns about degraded carrageenan (known as poligeenan) causing inflammation, but the form used in food and oral care products is undegraded carrageenan, which regulatory bodies including Food Standards Australia New Zealand consider safe. Those wishing to avoid it can find carrageenan-free toothpaste options among the natural brands at Toothpasteology.
Found in: Gel toothpastes, some mainstream toothpastes
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Cetylpyridinium Chloride (CPC)
Also known as: CPC, 1-hexadecylpyridinium chloride
What it is
Cetylpyridinium chloride is a quaternary ammonium compound with broad-spectrum antimicrobial properties. It is one of the most commonly used active ingredients in over-the-counter antiseptic mouthwashes and has been in use since the 1940s.
What it does in oral care
CPC works by disrupting the cell membranes of bacteria, killing them on contact. In mouthwash, it helps reduce plaque-forming bacteria and bacteria associated with bad breath (halitosis), supporting overall gum health.
What to know
CPC is approved as an active ingredient in oral antiseptic products by the TGA and is considered safe for regular daily use at the concentrations found in consumer mouthwash products. Like chlorhexidine, it can cause temporary tooth staining with prolonged or heavy use, though this is generally less pronounced.
Found in: Antiseptic mouthwashes, breath-freshening rinses, some toothpastes (e.g. Cepacol, some Colgate formulas)
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Chlorhexidine
Also known as: Chlorhexidine gluconate (CHG), chlorhexidine digluconate
What it is
Chlorhexidine is a powerful antiseptic agent used in medicine and dentistry to kill a broad spectrum of bacteria and fungi. In oral care it is most commonly found as chlorhexidine gluconate. It works by binding to bacterial cell membranes and disrupting them, causing cell death.
What it does in oral care
Chlorhexidine mouthwash is a clinically recognised antiseptic agent used to reduce plaque-forming bacteria and support gum health. It is commonly recommended by dentists for short-term use following gum treatment or oral surgery, and in professionally supervised oral health care programmes. It may also be recommended by dental or medical professionals for use in managing mouth ulcers or fungal oral conditions; use for these purposes should follow professional guidance.
What to know
Chlorhexidine is generally recommended for short-term use under dental guidance rather than as an everyday mouthwash. Prolonged use can cause tooth and tongue staining, altered taste, and may affect the balance of oral bacteria. It is not typically found in standard retail toothpastes but is available in specialist mouthwash products.
Found in: Prescription and pharmacy-grade mouthwashes, post-surgical rinses, medicated oral gels
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Cocamidopropyl Betaine
Also known as: CAPB, cocoamidopropyl betaine
What it is
Cocamidopropyl betaine is a mild surfactant derived from coconut oil. It belongs to a class of compounds called zwitterionic (or amphoteric) surfactants, meaning it can carry both positive and negative electrical charges. It was introduced as a gentler alternative to harsher surfactants like SLS.
What it does in oral care
In toothpaste and mouthwash, cocamidopropyl betaine provides foam and cleaning action, helping to remove plaque, food particles, and debris from the teeth and gums. Because it is milder than SLS, it is often preferred for sensitive mouth formulas and is a common ingredient in SLS-free toothpaste options.
What to know
Cocamidopropyl betaine is well-tolerated by most people and is considered a lower-irritancy alternative to SLS. However, it is not entirely irritant-free — it has been identified as an occasional allergen, appearing on patch-test panels for contact dermatitis. For most consumers, particularly those switching from SLS toothpaste, it is a safe and effective alternative.
Found in: SLS-free toothpastes, natural toothpastes, sensitive oral care formulas, some mouthwashes
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Coconut Oil
Also known as: Cocos nucifera oil, virgin coconut oil
What it is
Coconut oil is a plant-based oil extracted from the flesh of mature coconuts. It is rich in medium-chain fatty acids, particularly lauric acid, which has documented antibacterial properties. In oral care, it is used both as an ingredient in formulated products and on its own as part of a traditional practice called oil pulling.
What it does in oral care
In coconut oil toothpaste, it acts as a natural surfactant and antibacterial agent, helping to reduce harmful oral bacteria as part of regular oral hygiene. Lauric acid has been shown to disrupt bacterial cell membranes. Coconut oil is also used as a base in some fluoride-free and natural toothpaste formulations, providing a smooth texture.
What to know
While coconut oil shows promising antimicrobial activity, the clinical evidence for coconut oil toothpaste specifically is still limited compared to conventional formulations. It does not contain fluoride, so those relying solely on it for cavity prevention should be aware of this. Toothpasteology carries coconut oil toothpastes alongside fluoride options for informed comparison.
Found in: Natural toothpastes, fluoride-free toothpastes, oil-based dental products
Link to this termF
Fluoride
Also known as: Sodium fluoride (NaF), Stannous fluoride (SnF₂), Sodium monofluorophosphate (MFP)
What it is
Fluoride is a naturally occurring mineral that has been added to toothpaste since the 1950s. It comes in several forms — the most common being sodium fluoride, while stannous fluoride (also called tin fluoride) is used in some sensitivity and gum-care formulas. Sodium monofluorophosphate is another form found in many everyday toothpastes.
What it does in oral care
Fluoride strengthens tooth enamel by helping to remineralise areas weakened by acid from food and bacteria. It also interferes with the bacteria that contribute to decay, making fluoride toothpaste a widely recommended option for cavity prevention. Stannous fluoride is also used in products formulated for sensitivity relief and gum-care support.
What to know
Fluoride has a well-established safety record at the concentrations used in toothpaste. Bodies including the Australian Dental Association (ADA) and the National Health and Medical Research Council (NHMRC) endorse its use. Some consumers prefer fluoride-free toothpaste — if that applies to you, Toothpasteology stocks a range of fluoride-free options alongside fluoride formulas.
Found in: Everyday cavity-protection toothpastes, sensitivity toothpastes, children's toothpastes, whitening toothpastes, prescription-strength toothpastes
Link to this termG
Glycerin (Glycerol)
Also known as: Glycerol, glycerine, E422
What it is
Glycerin (also called glycerol or glycerine) is a clear, odourless, viscous liquid that occurs naturally in plant and animal fats. For use in oral care, it is typically derived from plant oils such as soy or palm, or produced synthetically. It is one of the most common ingredients in glycerin toothpaste.
What it does in oral care
Glycerin functions as a humectant in toothpaste, holding moisture in the formula to keep it smooth, pliable, and pleasant to use. It also contributes a mild sweetness and helps bind other ingredients together. Without humectants like glycerin, toothpaste would dry out and crack. It is a foundational ingredient in the vast majority of commercial and natural toothpastes.
What to know
Glycerin is widely regarded as safe and non-toxic. A fringe concern circulates online suggesting glycerin coats teeth and prevents remineralisation, but this is not supported by peer-reviewed dental research. Glycerin is rinsed away during brushing with negligible residue. Consumers seeking plant-derived glycerin can look for products certified vegan or stating vegetable glycerin on the label.
Found in: Almost all toothpastes, most mouthwashes
Link to this termH
Hydrogen Peroxide
Also known as: H₂O₂; carbamide peroxide (a related compound that breaks down to hydrogen peroxide)
What it is
Hydrogen peroxide is a mild antiseptic and oxidising agent that has been used in dental care for well over a century. It is a clear liquid that releases oxygen on contact with organic material. Carbamide peroxide (also called urea peroxide) is a related compound used in professional and at-home whitening gels that breaks down into hydrogen peroxide when applied to teeth.
What it does in oral care
Hydrogen peroxide works by penetrating the enamel and breaking down pigment molecules that cause surface staining. In mouthwash, it is used as a mild antiseptic to help reduce oral bacteria and freshen breath. At the low concentrations permitted in over-the-counter products, it is considered acceptable for regular use within the guidelines set by the TGA.
What to know
The concentration of hydrogen peroxide in over-the-counter products sold in Australia is regulated. Products containing above 6% hydrogen peroxide are restricted to dental professionals. Products containing very low concentrations of hydrogen peroxide help remove surface stains through regular use, consistent with their permitted cosmetic use in Australia.
Found in: Whitening toothpastes, whitening mouthwashes, professional whitening gels (as carbamide peroxide)
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Hydroxyapatite / Nano-Hydroxyapatite
Also known as: HAp, nHAp, nano-HAp, calcium hydroxyapatite
What it is
Hydroxyapatite is the mineral that makes up roughly 97% of tooth enamel and 70% of dentine — it is literally what teeth are made of. Nano-hydroxyapatite is the same compound produced as ultra-fine particles, which allows it to penetrate and integrate into enamel more effectively. It originated in research by JAXA (the Japanese space agency) in the 1970s and has since become a key active ingredient in fluoride-free and remineralising toothpastes.
What it does in oral care
Hydroxyapatite toothpaste works by depositing mineral directly onto the enamel surface, filling microscopic scratches and early lesions. Nano-hydroxyapatite toothpaste is used in products designed for enamel remineralisation and is included in formulas marketed for sensitive teeth. Some emerging evidence suggests it may offer remineralisation benefits, though the long-term evidence base is still developing compared to fluoride. It is also biocompatible — meaning it is recognised as a natural part of tooth structure rather than a foreign substance.
What to know
Nano-hydroxyapatite is not yet as extensively studied over decades as fluoride, but the evidence base is growing. It is considered safe for use in oral care products by the Scientific Committee on Consumer Safety (SCCS) and has not raised safety concerns with the TGA at concentrations used in consumer toothpastes. It is the ingredient of choice for many consumers seeking a fluoride-free remineralising option. Toothpasteology carries a curated range of nano-hydroxyapatite toothpastes from leading brands.
Found in: Fluoride-free remineralising toothpastes, sensitivity toothpastes, natural and premium oral care formulas
Link to this termM
Menthol
Also known as: L-menthol, peppermint menthol, natural menthol
What it is
Menthol is an organic compound derived from peppermint or other mint plants (or synthesised identically in a lab). It is responsible for the characteristic cool, fresh sensation associated with most toothpastes and mouthwashes.
What it does in oral care
In menthol toothpaste, menthol activates cold-sensitive receptors in the mouth — creating a perception of coolness without actually lowering temperature. This fresh sensation signals cleanliness and freshness, making it the dominant flavour profile in oral care. Menthol also has mild antimicrobial properties and is one of the four active ingredients in Listerine mouthwash.
What to know
Menthol is considered safe at the concentrations used in oral care products by regulators including Australia's TGA and the EU's Scientific Committee on Consumer Safety. Some individuals with oral sensitivity or allergies to mint may prefer menthol-free formulations. Menthol is not recommended in products for very young children as it can cause breathing difficulties in infants — always check age-appropriate labelling.
Found in: Most toothpastes, most mouthwashes, breath-freshening products
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Microplastics
Also known as: Polyethylene beads, plastic microbeads, PE particles
What it is
Microplastics in toothpaste traditionally referred to tiny plastic microbeads — most commonly polyethylene (PE) — added as a scrubbing agent or decorative element (the coloured specks in some toothpastes). They are plastic particles smaller than 5mm in diameter.
What it does in oral care
Microbeads were originally added to toothpaste as a mild abrasive or simply for visual appeal. They do not provide any meaningful oral health benefit beyond what silica or calcium carbonate abrasives already deliver. Professional dental bodies raised concerns that the beads could become trapped under the gum line, potentially harbouring bacteria — a factor that contributed to industry phase-out decisions.
What to know
Australia banned rinse-off cosmetic products containing plastic microbeads under the Industrial Chemicals (Notification and Assessment) Act, following voluntary phase-outs by major brands. Most mainstream toothpastes no longer contain intentionally added plastic microbeads. However, some researchers note that plastic fragments may still enter toothpaste formulations through certain raw material supply chains — an area of ongoing investigation. At Toothpasteology, all products listed are sourced from brands that do not intentionally add microplastics.
Found in: Historically in some whitening toothpastes; effectively phased out in Australia
Link to this termN
Neem
Also known as: Azadirachta indica, Indian lilac, Margosa
What it is
Neem is a tree native to the Indian subcontinent whose twigs have been used as a natural teeth-cleaning tool for thousands of years in Ayurvedic tradition. Neem extract used in modern oral care products is typically derived from the leaves, bark, or seed oil of the tree.
What it does in oral care
Neem contains natural compounds — including nimbidin and nimbin — that have shown some antibacterial and anti-inflammatory activity in preliminary laboratory research. In neem toothpaste, it is used to help control plaque-causing bacteria and freshen breath, and is included in products designed for everyday oral hygiene. It is a popular ingredient in natural and Ayurvedic oral care formulations.
What to know
Clinical evidence for neem in oral care is growing but not yet as robust as for conventional antibacterial agents like chlorhexidine. Neem toothpaste is generally considered safe for adults, though its strong, slightly bitter taste is not for everyone. Toothpasteology stocks a range of neem toothpastes for those seeking a more natural alternative.
Found in: Natural toothpastes, Ayurvedic toothpastes, herbal mouthwashes
Link to this termP
Parabens
Also known as: Methylparaben, propylparaben, ethylparaben, butylparaben, E218, E216
What it is
Parabens are a family of synthetic preservatives commonly used across cosmetics, pharmaceuticals, and personal care products to prevent the growth of bacteria, mould, and yeast. They have been used since the 1950s and remain one of the most effective and cost-efficient preservatives available.
What it does in oral care
In oral care products, parabens prevent microbial contamination and extend shelf life. A toothpaste without any preservative system can become a breeding ground for bacteria over time, particularly once the tube is opened. Parabens are effective at very low concentrations across a wide range of pH levels, making them useful in many formulations.
What to know
Parabens have faced scrutiny since a 2004 study detected them in breast tumour tissue, raising questions about their oestrogen-mimicking properties. However, major health regulators including Australia's TGA and the EU's Scientific Committee on Consumer Safety have assessed the evidence and continue to consider short-chain parabens (methylparaben, ethylparaben) safe at current use levels in cosmetic and oral care products. Note that the EU has placed restrictions on certain longer-chain parabens (propylparaben, butylparaben) in leave-on products, though this does not apply to rinse-off oral care products. Many brands now offer paraben-free formulations for consumers who prefer to avoid them — Toothpasteology stocks a wide range.
Found in: Some mainstream toothpastes and mouthwashes; largely absent from natural and organic formulations
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Potassium Nitrate
Also known as: KNO₃, saltpetre (historically)
What it is
Potassium nitrate is an inorganic salt that has been used as an active desensitising ingredient in toothpaste since the 1980s. It is the key active ingredient in many popular sensitivity toothpastes, including several Sensodyne formulas.
What it does in oral care
Potassium nitrate toothpaste works by gradually saturating the fluid within the dentinal tubules — the tiny channels in dentine that connect to tooth nerves. This raises the threshold at which nerve cells fire, reducing the painful response to triggers like cold food, hot drinks, or sweet foods. Consistent daily use over two to four weeks is typically recommended to allow the ingredient's protective effect to develop.
What to know
Potassium nitrate is one of the two main active ingredients for sensitivity relief (the other being stannous fluoride). It has a long history of use in sensitivity toothpastes and is included in products approved by regulatory bodies including the TGA. It is considered appropriate for long-term daily use at the concentrations found in sensitivity toothpastes. Those looking for a sensitivity toothpaste should check the label for either potassium nitrate or stannous fluoride as the active ingredient.
Found in: Sensitivity toothpastes (e.g. Sensodyne Rapid Relief, various Colgate Sensitive formulas)
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Propylene Glycol
Also known as: PG, propane-1,2-diol
What it is
Propylene glycol is a synthetic organic compound that is colourless, odourless, and slightly sweet. It is classified as a humectant — a substance that attracts and retains moisture — and is used widely across food, pharmaceutical, and cosmetic products. It is generally recognised as safe for consumption by regulatory authorities.
What it does in oral care
In toothpaste and mouthwash, propylene glycol serves as a humectant to prevent the product from drying out, and as a solvent to help dissolve and evenly distribute other ingredients. It helps give toothpaste its smooth, consistent texture.
What to know
Propylene glycol is considered safe at the concentrations used in oral care products by regulatory bodies including the TGA and the US FDA. Some consumers prefer to avoid it due to general concerns about synthetic ingredients. Propylene glycol-free toothpastes do exist, often within natural or 'clean' formulation ranges.
Found in: Mainstream toothpastes, mouthwashes, gel toothpastes
Link to this termS
Silica (Hydrated Silica)
Also known as: Hydrated silica, silicon dioxide, amorphous silica, SiO2
What it is
Silica is a mineral compound derived from quartz or sand, processed into a fine powder or gel form for use in toothpaste. Hydrated silica — the most common form found in silica toothpaste — is an amorphous (non-crystalline) form with a soft, abrasive texture.
What it does in oral care
Silica is used as an abrasive agent that physically removes surface stains and plaque from tooth enamel. It is the most widely used abrasive in modern toothpaste, found in both whitening and everyday formulas. Unlike older abrasives such as calcium carbonate, silica can be manufactured with very precise particle sizes, allowing formulators to control the level of abrasiveness.
What to know
The silica used in toothpaste is hydrated (amorphous) silica, which is considered safe at the concentrations used in oral care products by regulators including Australia's TGA and the European Commission's Scientific Committee on Consumer Safety — it is not the same as crystalline silica (quartz dust), which poses inhalation risks in industrial settings. Silica is found in the vast majority of mainstream toothpastes.
Found in: Whitening toothpastes, everyday toothpastes, most mainstream toothpaste formulas
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Sodium Benzoate
Also known as: E211, benzoate of soda
What it is
Sodium benzoate is the sodium salt of benzoic acid — a common preservative used in foods, beverages, pharmaceuticals, and personal care products. It is found naturally in some fruits and spices, and the synthetic form used in manufacturing is chemically identical.
What it does in oral care
In toothpaste and mouthwash, sodium benzoate functions as a preservative, preventing the growth of bacteria, yeast, and moulds that could otherwise spoil the product during its shelf life. It helps maintain product safety and stability between manufacture and use.
What to know
Sodium benzoate is approved for use in oral care and food products by Food Standards Australia New Zealand (FSANZ) and is assessed as acceptable in cosmetic/personal care products at permitted concentrations. A widely discussed concern involves its potential to form benzene (a known carcinogen) when combined with ascorbic acid (vitamin C) in beverages — however, this reaction is not relevant in typical toothpaste formulations, which do not contain ascorbic acid.
Found in: Toothpastes, mouthwashes, and a wide range of consumer personal care products
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Sodium Bicarbonate (Baking Soda)
Also known as: Baking soda, bicarb, bicarbonate of soda, NaHCO₃
What it is
Sodium bicarbonate is a mild alkaline salt that most Australians know as baking soda from their kitchen cupboard. It is one of the oldest teeth-cleaning agents in existence, having been used as a tooth powder long before commercial toothpaste existed. It is water-soluble and breaks down safely in the mouth.
What it does in oral care
Baking soda teeth benefits come from its mild abrasiveness, which helps remove surface stains and plaque, and from its alkalinity, which helps neutralise acids in the mouth, supporting a more balanced oral environment. Sodium bicarbonate toothpaste tends to leave the mouth feeling very clean and fresh.
What to know
Baking soda has a low abrasiveness rating (RDA), making it gentler on enamel than many other abrasives. It lacks fluoride, so sodium bicarbonate toothpaste formulas are often combined with fluoride or other active ingredients to support cavity prevention as part of a daily oral hygiene routine.
Found in: Whitening toothpastes, natural toothpastes, sensitive toothpastes, baking soda-specific formulas (e.g. Arm & Hammer, Red Seal)
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Sodium Lauryl Sulfate (SLS)
Also known as: SLS, sodium dodecyl sulfate (SDS), sodium laurilsulfate
What it is
Sodium lauryl sulfate is a synthetic surfactant — a foaming and cleansing agent derived from lauric acid, which is found naturally in coconut and palm oil. It is one of the most widely used detergents in personal care products and is responsible for the lather in most mainstream toothpastes.
What it does in oral care
In toothpaste, SLS loosens plaque and debris from teeth and helps distribute the paste evenly around the mouth during brushing. It is effective at cleaning but does not have therapeutic benefits beyond basic cleaning action.
What to know
Some consumers report a reduction in mouth ulcer frequency when switching to SLS-free formulas, though the clinical evidence for a direct causal link is mixed. SLS-free toothpaste is a popular alternative for those with sensitive gums or a tendency to develop ulcers. Sensodyne and several other leading brands offer SLS-free formulas — Toothpasteology stocks a wide selection if you are looking to switch.
Found in: Most mainstream toothpastes, some mouthwashes
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Sodium Saccharin
Also known as: Saccharin, E954
What it is
Sodium saccharin is an artificial sweetener derived from a compound originally found in coal tar. It is one of the oldest synthetic sweeteners in use and is around 300–500 times sweeter than table sugar, so only a tiny amount is needed.
What it does in oral care
In toothpaste and mouthwash, sodium saccharin makes the product taste pleasant without contributing to tooth decay. Unlike sugar, it is not fermented by oral bacteria, so it does not lower the pH of saliva or promote cavities. It works alongside flavouring agents to give toothpaste its palatable taste.
What to know
Sodium saccharin has been extensively reviewed and is considered safe at the levels used in oral care products by regulators including Food Standards Australia New Zealand. Some consumers prefer to avoid artificial sweeteners and opt for products sweetened with xylitol or stevia instead — Toothpasteology stocks options across both categories.
Found in: Most mainstream toothpastes, fluoride toothpastes, whitening toothpastes, mouthwashes
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Sorbitol
Also known as: D-sorbitol, E420, glucitol
What it is
Sorbitol is a sugar alcohol derived from glucose, found naturally in some fruits such as apples and pears. In toothpaste, it is produced synthetically and serves dual roles as both a sweetener and a humectant (moisture-retaining agent).
What it does in oral care
In sorbitol toothpaste, it keeps the paste moist and prevents it from drying out in the tube. It also contributes a mild sweetness without promoting tooth decay, since oral bacteria cannot ferment it into cavity-causing acids. It is one of the most common inactive ingredients in commercial toothpaste alongside glycerin.
What to know
Sorbitol is considered safe for use in oral care products by Food Standards Australia New Zealand and is well-tolerated by most people. It does not contribute to tooth decay, as oral bacteria cannot ferment it into acids. Those managing diabetes should consult their healthcare provider for personalised dietary and product guidance. Because it is not fully absorbed by the body if swallowed, consuming large amounts can cause digestive discomfort — but the amounts present in toothpaste are negligible when spitting properly. It is also suitable for people avoiding refined sugar.
Found in: Most mainstream toothpastes, sensitive toothpastes, mouthwashes
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Stannous Fluoride (Tin(II) Fluoride)
Also known as: Tin fluoride, SnF2
What it is
Stannous fluoride is a form of fluoride that combines fluoride ions with tin (stannous). It is distinct from the more common sodium fluoride in that it delivers two active components — fluoride for enamel strengthening and stannous (tin) ions for antibacterial action.
What it does in oral care
Stannous fluoride helps prevent cavities in the same way as other fluoride compounds, but it also helps control the bacteria that contribute to plaque, and is used in products formulated for sensitive teeth. It is the active ingredient in several sensitivity toothpastes and toothpastes marketed for gum care, including formulations of Sensodyne and Oral-B.
What to know
Stannous fluoride can cause temporary tooth staining in some people, particularly if used with certain other ingredients — look for stabilised formulations if this is a concern. It is not suitable for children under six. Fluoride dosage guidelines apply — follow label directions and the recommendations of the TGA and your dental professional. See also our full entry on Fluoride.
Found in: Sensitivity toothpastes, gum health toothpastes, all-in-one toothpastes
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Strontium Chloride
Also known as: Strontium chloride hexahydrate, SrCl2
What it is
Strontium chloride is a strontium salt that was used as an active desensitising agent in toothpaste from the 1960s onwards. It works differently from potassium nitrate — rather than calming nerve fibres, it physically blocks the microscopic tubules (dentinal tubules) in exposed dentine.
What it does in oral care
In strontium chloride toothpaste, the strontium ions are deposited into exposed dentinal tubules, forming a physical barrier that reduces the movement of fluid inside the tooth. This fluid movement is what triggers pain sensations in sensitive teeth when exposed to hot, cold, or sweet stimuli. With regular use, strontium chloride builds up this barrier, which is the intended mechanism of action in products formulated for sensitive teeth.
What to know
Strontium chloride has largely been replaced by potassium nitrate and stannous fluoride in newer sensitivity formulations, though some products — including the original Sensodyne — continue to use it. It has a long history of clinical use and remains a permitted active ingredient in therapeutic dental products registered with the TGA in Australia. Consumers should follow product label directions and consult their dentist if sensitivity persists.
Found in: Sensitivity toothpastes
Link to this termT
Tea Tree Oil
Also known as: Melaleuca alternifolia oil, melaleuca oil
What it is
Tea tree oil is an essential oil steam-distilled from the leaves of the Melaleuca alternifolia plant, native to Australia. It has been used for its natural antiseptic properties for decades and is a popular ingredient in natural personal care products.
What it does in oral care
In tea tree oil toothpaste, it acts as a natural antibacterial and antifungal agent. Tea tree oil contains terpinen-4-ol, a compound that has shown antibacterial activity in laboratory studies, and is used in products marketed for freshening breath and supporting everyday oral hygiene. It is particularly popular in natural and fluoride-free oral care formulations, including well-known Australian brands.
What to know
Tea tree oil should never be swallowed — it is toxic when ingested in significant amounts, which is why oral care products containing it are formulated to be spat out. At the low concentrations used in toothpaste, it is generally considered safe for most adults. Some individuals may experience sensitivity; discontinue use if irritation occurs.
Found in: Natural toothpastes, herbal mouthwashes, fluoride-free toothpastes, gum care products
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Thymol
Also known as: 2-isopropyl-5-methylphenol, thyme oil constituent
What it is
Thymol is a naturally occurring phenol compound found in thyme essential oil and other plants in the mint family. It is one of four active ingredients in Listerine mouthwash, which has used it since the product was first formulated in the late 19th century.
What it does in oral care
Thymol is an antiseptic with well-documented antibacterial and antifungal activity against oral bacteria, supported by decades of clinical use in registered oral care products. In mouthwash formulations, it works synergistically with eucalyptol, menthol, and methyl salicylate to help reduce plaque and support gum hygiene. Its antimicrobial action makes it a valuable ingredient in antiseptic mouthwash products.
What to know
Thymol has an extensive safety record in oral care and is recognised as effective by dental associations globally. At the concentrations used in mouthwash, it is safe for healthy adults. Products containing thymol are typically alcohol-based formulations; consumers seeking alcohol-free alternatives may need to choose a different mouthwash. Check thymol mouthwash ingredients lists if you have specific sensitivities.
Found in: Antiseptic mouthwashes, some natural toothpastes
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Titanium Dioxide
Also known as: TiO2, CI 77891
What it is
Titanium dioxide is a naturally occurring white mineral pigment widely used as a colouring agent across food, cosmetics, and oral care products. It is responsible for the bright white appearance of many toothpastes.
What it does in oral care
In titanium dioxide toothpaste, it serves as a whitening pigment that gives toothpaste its characteristic white colour and opaque appearance. It does not bleach or chemically whiten teeth — it simply makes the paste look white and uniform. It has no direct effect on oral bacteria or enamel.
What to know
The European Union banned titanium dioxide as a food additive in 2022 due to concerns about nano-particle absorption in the gut, though it remains permitted in cosmetics and oral care products (which are spat out). Australia's Therapeutic Goods Administration continues to assess its safety profile. Some consumers choose to avoid it; titanium dioxide-free toothpastes are available at Toothpasteology for those who prefer to opt out.
Found in: Most mainstream toothpastes, whitening toothpastes
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Triclosan
Also known as: 5-chloro-2-(2,4-dichlorophenoxy)phenol
What it is
Triclosan is a synthetic antibacterial and antifungal agent that was widely used in toothpastes, soaps, and cosmetics from the 1970s onwards. It was particularly associated with Colgate Total, which used triclosan as an active ingredient for gum health.
What it does in oral care
Triclosan was used in toothpaste to reduce plaque, prevent gingivitis, and provide broad-spectrum antibacterial protection in the mouth. Clinical studies showed it was genuinely effective at these tasks when used at the 0.3% concentration common in toothpastes.
What to know
Triclosan has been largely phased out of consumer products due to regulatory action in several countries. The US FDA banned it from consumer antiseptic soaps in 2016, citing concerns about potential hormonal disruption and contributions to antibiotic resistance. In Australia, most major brands voluntarily removed it from their formulations. Colgate Total reformulated without triclosan in 2019. You are unlikely to encounter it in products sold today, but it may still appear on older product labels.
Found in: Largely discontinued; was previously found in antibacterial toothpastes and hand soaps
Link to this termX
Xylitol
Also known as: Birch sugar, wood sugar
What it is
Xylitol is a naturally occurring sugar alcohol found in many fruits, vegetables, and birch bark. It tastes sweet like sugar but is metabolised differently in the body, providing around 40% fewer kilojoules. In oral care it is valued not for its sweetness but for its unique effect on the bacteria responsible for tooth decay.
What it does in oral care
The bacteria that cause cavities — primarily Streptococcus mutans — cannot properly metabolise xylitol the way they do regular sugar. When they absorb it, they are unable to produce energy or acid, which disrupts the cycle of tooth decay. Regular use of xylitol-containing oral care products may help support cavity prevention. Some evidence also suggests it can reduce levels of decay-associated bacteria, though individual results vary.
What to know
Xylitol is well-tolerated by most people at the amounts found in oral care products, though very large dietary quantities can cause digestive discomfort. It is important to note that xylitol is toxic to dogs, so keep xylitol-containing products out of their reach.
Found in: Natural toothpastes, fluoride-free toothpastes, children's toothpastes, mouthwashes, dental gums and mints
Link to this termZ
Zinc Citrate
Also known as: Zinc citrate trihydrate, trizinc dicitrate
What it is
Zinc citrate is a zinc salt of citric acid, and one of the most bioavailable forms of zinc used in oral care. Zinc is an essential trace mineral with natural antibacterial properties, and in its citrate form it is readily absorbed and well-tolerated in the mouth.
What it does in oral care
Zinc citrate in toothpaste is used to help manage the bacteria and volatile sulphur compounds (VSCs) associated with bad breath, and is a common active ingredient in anti-halitosis formulas. It also contributes to tartar (calculus) control by inhibiting the mineralisation of plaque, and is included in formulas designed to support gum health as part of a daily oral hygiene routine.
What to know
Zinc citrate is considered safe for use in oral care products at typical concentrations and has a well-established history of use in dental hygiene formulations. It is often paired with fluoride and other active ingredients to provide multi-benefit protection. If you are looking for a toothpaste that targets bad breath and tartar simultaneously, products containing zinc citrate are a strong option — Toothpasteology stocks several brands that use it.
Found in: Anti-bad-breath toothpastes, tartar-control toothpastes, gum health toothpastes and mouthwashes
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