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 33 of the most common — and some not-so-common — ingredients in oral care, from actives like fluoride and hydroxyapatite to preservatives, surfactants, abrasives and botanicals.
Each entry explains what the ingredient is, the job it does inside a formulation, and the practical trade-offs worth knowing before you buy. Click any letter to jump to a section, or search above.
One thing to understand first, because it shapes how this page is written. In Australia most toothpaste and mouthwash is regulated as a cosmetic or as "excluded goods". The moment a product is presented as treating a condition — sensitivity, gum disease, oral thrush — it becomes a therapeutic good and has to be assessed and listed on the Australian Register of Therapeutic Goods before it can be sold on that basis. So there are things we won't tell you here: we don't make claims about what an ingredient does to your teeth, we don't recommend ingredients for conditions, and we're not a substitute for a dental professional. Where an ingredient is a regulated therapeutic active, we say so and stop there.
A
Activated Charcoal
Also known as: activated carbon, activated charcoal powder
What it is
Charcoal processed at high temperature to create an extremely porous structure with a very large surface area, which lets it bind other substances on contact. The same material has long-standing uses in emergency medicine, at doses and purities unrelated to anything in a toothpaste tube.
Its role in a formulation
Charcoal is used as an abrasive and as a visual signature — it produces the distinctive black paste or powder that is the whole point of the category aesthetically.
Trade-offs worth knowing
Abrasivity is the live question. Charcoal particles vary substantially between products, and most brands do not publish an RDA (relative dentine abrasivity) figure, which makes comparison difficult. It is messy in practice — it stains grout, cloths and some brush heads. Most charcoal formulations are fluoride-free, which is a straightforward compositional fact worth checking against what you want. Independent evidence for charcoal specifically is thinner than for long-established abrasives such as silica, and several dental bodies internationally have published caution about frequent use.
If you're comparing products
look for a published RDA figure, check whether the formulation includes fluoride, and check whether it is a paste or a powder — powders behave quite differently on a wet brush.
Found in: natural and "detox"-style toothpastes, whitening powders, charcoal formulations.
Link to this term
Aloe Vera
Also known as: Aloe barbadensis miller, aloe gel
What it is
The gel from the inner leaf of a succulent plant, used in traditional preparations for a very long time and now common across skincare, sun care and oral care.
Its role in a formulation
Aloe is used as a base and texture ingredient, and as a positioning ingredient — it signals a plant-forward formulation to shoppers who want one. It contributes to mouthfeel rather than to cleaning.
Trade-offs worth knowing
It is well tolerated by most people and is usually present as a supporting ingredient rather than a primary one, so the practical difference between an aloe formulation and a non-aloe one is mostly texture and taste. Laboratory research on aloe compounds exists, but we're not in a position to tell you what that means for your mouth. Aloe is plant-derived, which matters if you're buying to a vegan standard, though check the rest of the ingredient list rather than assuming.
Found in: natural toothpastes, herbal mouthwashes, gel formulations.
Link to this termB
Benzalkonium Chloride
Also known as: BAC, BAK, ADBAC
What it is
A quaternary ammonium compound used as a preservative and antiseptic across medical, household and personal care products for decades, including in some eye drops and nasal sprays.
Regulatory note
In oral care this is an antiseptic active. Products presented as antiseptic or as managing an oral condition are regulated as therapeutic goods in Australia and must be listed on the ARTG. We don't stock or describe products on that basis, and we can't tell you what it will do in your mouth.
Trade-offs worth knowing
Research into irritancy at higher concentrations exists, largely from nasal and ophthalmic contexts rather than oral. If you know you react to quaternary ammonium compounds, this is one to check the label for. The European Scientific Committee on Consumer Safety has assessed it as safe at permitted cosmetic levels.
Found in: some mouthwashes and oral rinses.
Link to this termC
Calcium Carbonate
Also known as: chalk, precipitated calcium carbonate, CaCO₃
What it is
A naturally occurring mineral — the main component of limestone, chalk and marble. Pharmaceutical-grade calcium carbonate is also used as a dietary supplement and antacid. It is one of the oldest abrasives in toothpaste.
Its role in a formulation
An abrasive and mild polishing agent. Abrasives are what physically lift plaque film and surface debris during brushing; without one, a toothpaste is essentially flavoured gel.
Trade-offs worth knowing
Calcium carbonate sits in the low-to-moderate range on RDA scales, so it is a middle-of-the-road choice on abrasivity. Its particle size is harder to control precisely than silica's, which is why formulators chasing a specific abrasivity target often reach for silica instead. It has a slightly chalkier mouthfeel that some people prefer and others don't. It's mineral-derived and inexpensive, which is why it's common in natural and children's ranges.
Found in: natural toothpastes, everyday and children's formulations, polishing pastes.
Link to this term
Carrageenan
Also known as: E407, Irish moss extract
What it is
A polysaccharide extracted from red seaweed, used as a thickener and stabiliser across food and personal care for decades.
Its role in a formulation
A binder. It holds the paste together and stops the liquid and solid components separating in the tube. Without a binder of some kind, toothpaste goes grainy or splits.
Trade-offs worth knowing
Consumer concern about carrageenan centres on degraded carrageenan (poligeenan), which is a different substance from the undegraded form used in food and oral care. Food Standards Australia New Zealand permits the undegraded form. It is seaweed-derived, so it suits vegan formulations. If you prefer to avoid it, alternatives include xanthan gum and cellulose gum — check the binder line on the ingredient list rather than the marketing.
Found in: gel toothpastes, some mainstream formulations.
Link to this term
Cetylpyridinium Chloride (CPC)
Also known as: CPC
What it is
A quaternary ammonium compound, in use since the 1940s and one of the most common actives in over-the-counter antiseptic mouthwash.
Regulatory note
CPC is an antimicrobial active. Products presented on that basis are therapeutic goods in Australia and require ARTG listing. We can't describe what it does in your mouth or recommend it for anything.
Trade-offs worth knowing
Temporary tooth staining with prolonged or heavy use is a documented and widely reported characteristic — generally less pronounced than with chlorhexidine, but worth knowing before you commit to a bottle. It is also a common cause of the strong taste some people find unpleasant.
Found in: antiseptic and breath-freshening mouthwashes, some toothpastes.
Link to this term
Chlorhexidine
Also known as: chlorhexidine gluconate, CHG
What it is
A potent antiseptic used in medicine and dentistry, most commonly as the gluconate salt.
Regulatory note
This is a pharmacy and prescription-grade therapeutic ingredient, not a retail cosmetic one. In Australia it is used under professional direction — typically short-term, following dental treatment. We don't stock it, and if a dentist has recommended it, follow their direction rather than anything you read online, including here.
Trade-offs worth knowing
Even used as directed, chlorhexidine is well documented as causing tooth and tongue staining and altered taste with prolonged use, which is a large part of why it is prescribed in short courses.
Found in: pharmacy and prescription mouthwashes, post-surgical rinses.
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Cocamidopropyl Betaine
Also known as: CAPB
What it is
A surfactant derived from coconut oil, in a class called amphoteric surfactants — meaning the molecule can carry both positive and negative charge. It was developed as a gentler alternative to harsher detergents.
Its role in a formulation
It provides foam and helps carry the paste around the mouth. Foam does very little cleaning by itself, but it distributes the formulation and it is a strong driver of whether a toothpaste feels like it's working.
Trade-offs worth knowing
Milder than SLS and the usual substitute in SLS-free formulations, but not inert — it appears on contact dermatitis patch-test panels and is a recognised occasional allergen. It foams less than SLS, which some people read as the paste underperforming; it isn't, but it is an adjustment. Coconut-derived, so relevant if you're avoiding palm.
Found in: SLS-free and natural toothpastes, some mouthwashes.
Link to this term
Coconut Oil
Also known as: Cocos nucifera oil
What it is
Oil pressed from mature coconut flesh, high in medium-chain fatty acids, particularly lauric acid.
Its role in a formulation
A base and texture ingredient in oil-forward pastes, and the basis of oil pulling, a traditional practice rather than a clinical one.
Trade-offs worth knowing
It changes the texture substantially — oil-based pastes feel quite different from gel or standard pastes and it's worth trying a small size first. Coconut oil solidifies below roughly 24°C, so in cooler climates some products firm up in the tube or jar. Lab research on lauric acid exists; clinical evidence for coconut oil in oral care is limited relative to conventional formulations, and we'd rather say that plainly than imply more. Most coconut oil formulations are fluoride-free — a compositional fact to check against what you're after.
Found in: natural and fluoride-free toothpastes, oil pulling products.
Link to this termF
Fluoride
Also known as: sodium fluoride (NaF), stannous fluoride (SnF₂), sodium monofluorophosphate (MFP)
What it is
A naturally occurring mineral, added to toothpaste since the 1950s in several forms. Sodium fluoride is the most common; sodium monofluorophosphate appears in many everyday pastes; stannous fluoride has its own entry below.
What the dental authorities say
We won't characterise fluoride's effects in our own words, but we'll point you to the people whose job it is. The Australian Dental Association's Policy Statement 2.2.1 states that "toothpastes containing fluoride should be used as an important method of further reducing tooth decay risk, regardless of whether or not the area water supply is optimally fluoridated." Fluoride's use in oral care is also supported by the National Health and Medical Research Council. If you want a position on fluoride, that is the authoritative Australian one and it is easy to look up.
Concentration, which is the practically useful part
Australian guidance sets age-related thresholds: no toothpaste before 18 months; low-fluoride toothpaste at around 500ppm, used as a smear, from 18 months to six years; standard-strength toothpaste at 1000–1450ppm, used as a pea-sized amount, from age six. A dental professional may advise differently for an individual child. Concentration in ppm is printed on the pack — it is the single most useful number on a fluoride toothpaste and most people never look at it.
Trade-offs worth knowing
Some people prefer fluoride-free formulations, for reasons ranging from taste to ingredient philosophy. That is a legitimate choice and we stock both fluoride and fluoride-free ranges, without a view on which you should make. If you are choosing fluoride-free, it is worth having that conversation with your dentist rather than with a shop.
Found in: everyday, children's, whitening and specialist toothpastes.
Link to this termG
Glycerin (Glycerol)
Also known as: glycerol, glycerine, E422
What it is
A clear, viscous liquid occurring naturally in plant and animal fats, produced for oral care from plant oils such as soy or palm, or synthetically.
Its role in a formulation
A humectant — it holds moisture in the paste so it stays smooth and doesn't dry out or crack. It also adds mild sweetness and helps bind the formulation. It's in the overwhelming majority of toothpastes, natural and mainstream alike.
Trade-offs worth knowing
There's a persistent online claim that glycerin coats teeth and blocks mineral uptake; it isn't supported by peer-reviewed dental research, and glycerin is water-soluble and rinses away. The more practical consideration is sourcing: glycerin can be palm-derived, so if you're avoiding palm, look for products specifying vegetable or non-palm glycerin, or certified alternatives. Glycerin-free pastes exist but are uncommon and tend to have a shorter open shelf life.
Found in: almost all toothpastes and 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
A mild oxidising agent used in dentistry for over a century. It releases oxygen on contact with organic material.
Regulatory note — read this one before you buy anything imported
Peroxide concentration in tooth-whitening products sold in Australia is controlled under the Poisons Standard, and higher-concentration products are restricted to supply by dental professionals. Concentrations that are legal at retail overseas are not necessarily legal here, and the ACCC has taken enforcement action on non-compliant imported whitening products. If you are buying a whitening product from an overseas site, check the concentration against Australian scheduling before it ships.
Trade-offs worth knowing
Peroxide products commonly carry directions limiting frequency and duration of use — worth reading rather than assuming. Sensitivity during use is a widely reported experience with peroxide whitening and is one of the main reasons people abandon a course.
Found in: whitening toothpastes and rinses, professional whitening gels.
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Hydroxyapatite / Nano-Hydroxyapatite
Also known as: HAp, nHAp, calcium hydroxyapatite
What it is
A naturally occurring calcium phosphate mineral. It is the principal mineral component of bone and of teeth. Nano-hydroxyapatite is the same compound manufactured as ultra-fine particles; non-nano or micro-hydroxyapatite is the same compound at larger particle size. Its development for consumer use traces to Japanese research from the 1970s.
Its role in a formulation
Hydroxyapatite is the defining active in a large and growing category of fluoride-free toothpaste, and it is the ingredient most responsible for the current shape of the premium oral care market.
What we're not going to tell you
Whether hydroxyapatite repairs, rebuilds or remineralises enamel is exactly the kind of question we can't answer as a retailer — in Australia those are therapeutic claims, and making them would put a product into a regulatory category it isn't in. Research is published and ongoing; the evidence base is younger than fluoride's; and your dentist is the right person to interpret it for your mouth. We'd rather point you there than sell you a sentence we can't stand behind.
Trade-offs worth knowing — the parts we can be useful on
Particle size is the main formulation variable: nano and non-nano versions are both widely sold, and brands choose between them for different reasons. Note that the EU has placed restrictions on nano-hydroxyapatite in cosmetics, which is a regulatory divergence rather than an Australian position, but it's the source of most of the "is it banned in Europe?" material you'll find online — worth understanding rather than being alarmed by. Concentration varies enormously between products and is not always disclosed; where a brand publishes a percentage, that's a point of comparison. Hydroxyapatite is white and does not tint the paste. Most hydroxyapatite formulations are fluoride-free, though combination products exist. Sourcing varies — some is synthetic, some is derived from animal or mineral sources — which matters if you're buying to a vegan standard, so check with the brand.
Found in: fluoride-free premium and natural toothpastes.
Link to this termM
Menthol
Also known as: L-menthol, peppermint menthol
What it is
An organic compound from peppermint and other mint plants, or synthesised to be chemically identical. It's responsible for the cooling sensation in most toothpaste.
Its role in a formulation
Flavour and sensory signal. Menthol activates cold-sensitive receptors, creating a perception of coolness without any temperature change. That sensation is what most people actually mean when they say a toothpaste feels like it's working.
Trade-offs worth knowing
Menthol intensity is the single most common reason people dislike a toothpaste, and it varies far more between products than the packaging suggests — imported and premium brands in particular often run considerably milder or stranger than supermarket mint. If you're buying for someone who finds mint overwhelming, or for a child, mild and menthol-free formulations are a real category, not a compromise. Menthol is not recommended in products for very young children; check age labelling. Some people have a genuine mint sensitivity and should read flavour ingredients rather than assume.
Found in: most toothpastes and mouthwashes.
Link to this term
Microplastics
Also known as: polyethylene microbeads, PE particles
What it is
Plastic particles under 5mm, historically added to toothpaste as microbeads — the coloured specks in some older mainstream products.
Its role in a formulation
Mild abrasion and, mostly, visual appeal. They offered nothing that silica or calcium carbonate weren't already doing.
Trade-offs worth knowing
Australia has moved against plastic microbeads in rinse-off cosmetic products following voluntary industry phase-outs, and you are unlikely to encounter intentionally added microbeads in toothpaste sold here today. Some researchers continue to examine whether plastic fragments enter formulations through raw material supply chains; that's an area of ongoing work rather than a settled finding. If plastic content matters to you, packaging is now the more substantial question — tube material varies widely and metal, recyclable-mono-material and refillable formats all exist.
Found in: historically in some whitening toothpastes; effectively phased out.
Link to this termN
Neem
Also known as: Azadirachta indica, Indian lilac
What it is
Extract from the leaves, bark or seed oil of a tree native to the Indian subcontinent, whose twigs have been used for tooth cleaning for thousands of years in Ayurvedic tradition.
Its role in a formulation
A traditional and positioning ingredient in Ayurvedic and natural ranges, contributing a distinctive flavour profile.
Trade-offs worth knowing
The taste is the main thing: neem is strongly bitter and it is genuinely divisive — if you haven't used it, buy small. Laboratory research on neem compounds exists; clinical evidence in oral care is limited relative to conventional ingredients, and we'll leave interpretation of it to dental professionals. Neem formulations are typically fluoride-free.
Found in: natural and Ayurvedic toothpastes, herbal mouthwashes.
Link to this termP
Parabens
Also known as: methylparaben, propylparaben, ethylparaben, butylparaben
What it is
A family of synthetic preservatives used across cosmetics and personal care since the 1950s, and among the most effective and cheapest available.
Its role in a formulation
Preservation. An opened tube of toothpaste is a warm, moist environment repeatedly contacted by a used brush; without a preservative system, microbial growth is a genuine problem rather than a theoretical one. Parabens work at very low concentrations across a wide pH range, which is why they persisted.
Trade-offs worth knowing
Scrutiny dates to a 2004 study detecting parabens in breast tumour tissue and questions about oestrogen-mimicking activity. Regulators including the European Scientific Committee on Consumer Safety have since assessed the evidence and continue to permit short-chain parabens at current levels; the EU has restricted certain longer-chain parabens in leave-on products, which doesn't extend to rinse-off oral care. Many shoppers prefer to avoid them regardless, which is a perfectly reasonable preference, and paraben-free formulations are now the norm in natural ranges — they use alternative preservative systems such as sodium benzoate or phenoxyethanol rather than no preservative at all, which is worth knowing if "preservative-free" is what you thought you were buying.
Found in: some mainstream formulations; largely absent from natural ranges.
Link to this term
Potassium Nitrate
Also known as: KNO₃
What it is
An inorganic salt, used in oral care since the 1980s.
Regulatory note
Potassium nitrate is a desensitising active. In Australia, toothpastes presented as being for sensitive teeth are therapeutic goods requiring ARTG listing — this is the clearest example of the regulatory line described at the top of this page. We don't sell products on that basis and we can't advise on sensitivity. If you have tooth sensitivity, see a dentist: the cause matters, and some causes need attention rather than a different toothpaste.
Found in: sensitivity toothpastes, sold as therapeutic goods.
Link to this term
Propylene Glycol
Also known as: PG, propane-1,2-diol
What it is
A colourless, odourless, slightly sweet synthetic compound used across food, pharmaceutical and cosmetic manufacturing.
Its role in a formulation
A humectant and solvent — it stops the product drying out and helps dissolve and evenly distribute other ingredients.
Trade-offs worth knowing
Permitted in oral care at the concentrations used, and assessed by regulators including the TGA and US FDA. Avoidance is usually driven by a general preference against synthetic ingredients rather than a specific concern, which is a fine reason to choose otherwise — propylene glycol-free formulations are common in natural ranges, typically using glycerin or sorbitol to do the same job.
Found in: mainstream and gel toothpastes, mouthwashes.
Link to this termS
Silica (Hydrated Silica)
Also known as: hydrated silica, silicon dioxide, SiO₂
What it is
A mineral compound derived from quartz or sand and processed into fine powder or gel. The form in toothpaste is amorphous (non-crystalline) hydrated silica.
Its role in a formulation
The most widely used abrasive in modern toothpaste. Its advantage over older abrasives is manufacturing precision — silica can be produced at tightly controlled particle sizes, which lets formulators dial abrasivity deliberately rather than accept whatever the mineral gives them.
Trade-offs worth knowing
Because abrasivity is a formulation choice rather than a property of the ingredient, "contains silica" tells you very little on its own — a gentle everyday paste and an aggressive stain-removal paste may both list it. Where a brand publishes an RDA figure, that is the number to compare, and the willingness to publish one is itself a reasonable signal. Note that hydrated amorphous silica is not the same material as crystalline silica (quartz dust), which is an industrial inhalation hazard and unrelated to anything in a tube.
Found in: the large majority of toothpastes.
Link to this term
Sodium Benzoate
Also known as: E211
What it is
The sodium salt of benzoic acid, occurring naturally in some fruits and spices and manufactured synthetically as a chemically identical compound. A common food and cosmetic preservative.
Its role in a formulation
Preservation — it inhibits bacteria, yeast and mould over the product's shelf life. It's the most common paraben alternative in natural ranges.
Trade-offs worth knowing
The widely circulated concern involves benzene formation when sodium benzoate combines with ascorbic acid (vitamin C), which was a genuine issue in soft drinks. Toothpaste formulations don't generally contain ascorbic acid, so the reaction isn't relevant here. Permitted by Food Standards Australia New Zealand and in cosmetic use at specified concentrations.
Found in: toothpastes and mouthwashes across both natural and mainstream ranges.
Link to this term
Sodium Bicarbonate (Baking Soda)
Also known as: baking soda, bicarb, NaHCO₃
What it is
A mild alkaline salt, familiar from the kitchen cupboard, and one of the oldest tooth-cleaning agents there is — used as a tooth powder long before commercial toothpaste existed. Water-soluble.
Its role in a formulation
A mild abrasive, and a pH modifier — it's alkaline, which shifts the formulation's pH upward.
Trade-offs worth knowing
It sits low on abrasivity scales, making it one of the gentler abrasive choices. The distinctive salty, slightly soapy taste is the main practical consideration and it divides people sharply. It's inexpensive and simple, which suits minimal-ingredient formulations. Bicarb pastes are frequently fluoride-free, though combination formulations are common — check rather than assume.
Found in: natural, whitening and minimal-ingredient toothpastes.
Link to this term
Sodium Lauryl Sulfate (SLS)
Also known as: SLS, sodium dodecyl sulfate, sodium laurilsulfate
What it is
A synthetic surfactant derived from lauric acid, which occurs in coconut and palm oil. One of the most widely used detergents in personal care, and the source of the lather in most mainstream toothpaste.
Its role in a formulation
Foaming and distribution. It helps lift debris and spread the paste around the mouth. It's a cleaning agent, not an active.
Trade-offs worth knowing
This is the most commonly avoided ingredient in the category. Some people report a difference in mouth ulcer frequency when they switch away from it; the clinical evidence for a causal link is mixed, and we're not going to overstate it in either direction — but it's a common enough experience that SLS-free is now a mainstream product category rather than a niche. The practical consequence of switching is less foam, which takes a couple of weeks to stop feeling like the paste isn't working. SLS can be palm-derived, so it's relevant to palm-free shopping. If you're switching, cocamidopropyl betaine is the usual replacement — see its entry, since it isn't entirely irritant-free either.
Found in: most mainstream toothpastes, some mouthwashes.
Link to this term
Sodium Saccharin
Also known as: saccharin, E954
What it is
An artificial sweetener, among the oldest in use, roughly 300–500 times sweeter than sugar, so present in tiny quantities.
Its role in a formulation
Palatability. Unsweetened toothpaste is unpleasant enough that people brush for less time, which is the only reason sweeteners are in there at all. Saccharin isn't fermented by oral bacteria.
Trade-offs worth knowing
Reviewed extensively and permitted by Food Standards Australia New Zealand at the levels used. Preference against artificial sweeteners is the usual reason to avoid it; xylitol and stevia-sweetened alternatives are widely available. Some people detect a metallic aftertaste from saccharin specifically — if toothpaste has always tasted slightly off to you, this is a plausible culprit worth testing by switching.
Found in: most mainstream toothpastes and mouthwashes.
Link to this term
Sorbitol
Also known as: D-sorbitol, E420
What it is
A sugar alcohol derived from glucose and occurring naturally in fruits such as apples and pears; produced synthetically for manufacturing use.
Its role in a formulation
Doubles as humectant and sweetener — it keeps the paste from drying out and provides mild sweetness. Alongside glycerin, it's one of the two most common non-active ingredients in commercial toothpaste.
Trade-offs worth knowing
Not fermented into acid by oral bacteria. Permitted by Food Standards Australia New Zealand and well tolerated. Large dietary quantities of sugar alcohols can cause digestive discomfort, though the amount in toothpaste is negligible when you spit rather than swallow — relevant mainly for young children still learning to. If you're managing diabetes, questions about sugar alcohols are for your healthcare provider rather than a toothpaste retailer.
Found in: most mainstream toothpastes and mouthwashes.
Link to this term
Stannous Fluoride (Tin(II) Fluoride)
Also known as: tin fluoride, SnF₂
What it is
A fluoride compound combining fluoride ions with tin. It differs from sodium fluoride in delivering two components rather than one.
Regulatory note
Stannous fluoride is used both in everyday fluoride toothpaste and as an active in products presented for sensitivity and gum care. Where a product is presented on that second basis, it is a therapeutic good in Australia and requires ARTG listing — see the note at the top of this page.
Trade-offs worth knowing
Temporary tooth staining is a well-documented characteristic of stannous fluoride, more pronounced in unstabilised formulations; stabilised versions were developed specifically to address it, and it's worth checking which you're buying. Formulations containing it are generally not intended for children under six. Standard fluoride concentration guidance applies — see the Fluoride entry above.
Found in: everyday and specialist fluoride toothpastes.
Link to this term
Strontium Chloride
Also known as: strontium chloride hexahydrate, SrCl₂
What it is
A strontium salt used in oral care from the 1960s onward, largely superseded by later ingredients though still present in some long-established products.
Regulatory note
Like potassium nitrate, this is a desensitising active, and products presented for sensitive teeth are therapeutic goods in Australia. We don't sell on that basis and can't advise. If sensitivity is your issue, please see a dentist rather than a shop — persistent sensitivity can have causes that a toothpaste won't address.
Found in: sensitivity toothpastes, sold as therapeutic goods.
Link to this termT
Tea Tree Oil
Also known as: Melaleuca alternifolia oil
What it is
An essential oil steam-distilled from the leaves of a plant native to Australia, containing terpinen-4-ol among other compounds.
Its role in a formulation
A traditional and flavour ingredient in natural ranges, and one with genuine Australian provenance, which is part of its appeal here.
Safety note worth taking seriously
Tea tree oil is toxic if swallowed in meaningful quantity. Products containing it are formulated to be spat out, and they are not appropriate for young children still learning to do that reliably. If irritation occurs, stop using it.
Trade-offs worth knowing
The flavour is medicinal and strong — another buy-small-first ingredient. Laboratory research on its constituent compounds exists; clinical evidence in oral care is limited, and we'll leave that to dental professionals. Typically found in fluoride-free formulations.
Found in: natural toothpastes and herbal mouthwashes.
Link to this term
Thymol
Also known as: thyme oil constituent
What it is
A naturally occurring phenol found in thyme oil and related plants. It has been one of the four active constituents of Listerine since the late nineteenth century.
Regulatory note
Thymol functions as an antiseptic active in mouthwash. Products presented on that basis are therapeutic goods in Australia.
Trade-offs worth knowing
Thymol-containing mouthwashes are typically alcohol-based, which is the main practical consideration — the burn is significant, and alcohol-free alternatives are a substantial category if you don't want it. Alcohol content also matters for anyone avoiding it for personal or health reasons, and for recent oral surgery, where it's usually contraindicated on your dentist's advice.
Found in: antiseptic mouthwashes, some natural toothpastes.
Link to this term
Titanium Dioxide
Also known as: TiO₂, CI 77891
What it is
A naturally occurring white mineral pigment used as a colourant across food, cosmetics and oral care.
Its role in a formulation
Colour, and nothing else. It makes paste look bright, opaque and uniform. It does not bleach or chemically alter teeth, has no effect on oral bacteria, and is present purely because white paste sells better than beige paste. This is the clearest example in the glossary of an ingredient doing aesthetic rather than functional work.
Trade-offs worth knowing
The European Union banned titanium dioxide as a food additive in 2022 over nanoparticle absorption questions; it remains permitted in cosmetics and oral care, which are spat out rather than swallowed. That distinction is the source of most of the confusion around it. Titanium dioxide-free formulations are increasingly common across our natural range and simply look less white — if you've wondered why some premium and natural pastes are off-white or grey, this is usually why. Given that its only job is appearance, it's an easy one to skip if it bothers you.
Found in: many mainstream and whitening toothpastes.
Link to this term
Triclosan
Also known as: 5-chloro-2-(2,4-dichlorophenoxy)phenol
What it is
A synthetic antibacterial agent used widely in toothpastes, soaps and cosmetics from the 1970s, best known for its use in Colgate Total.
Where it stands now
Largely phased out of consumer products following regulatory action in several countries — the US FDA banned it from consumer antiseptic soaps in 2016, citing hormonal disruption questions and antibiotic resistance concerns. Australian brands removed it voluntarily, and Colgate Total was reformulated without it in 2019. You are very unlikely to encounter it in anything sold today; it's included here because it still appears on older labels and in a lot of out-of-date online writing.
Found in: effectively discontinued.
Link to this termX
Xylitol
Also known as: birch sugar, wood sugar
What it is
A sugar alcohol occurring naturally in fruits, vegetables and birch bark. It tastes like sugar, is metabolised differently, and carries roughly 40% fewer kilojoules.
Its role in a formulation
A sweetener, and the preferred one in natural ranges that avoid artificial sweeteners. It's not fermented into acid by oral bacteria in the way sugar is.
Trade-offs worth knowing
It tastes closer to sugar than saccharin does, without the metallic note some people detect, which is the main practical reason to prefer it. Research into xylitol and oral bacteria is published and ongoing; what it means for your teeth is a question for your dentist, not for us. Large dietary quantities of sugar alcohols can cause digestive discomfort, though not at toothpaste doses.
Important if you have a dog
Xylitol is highly toxic to dogs. Keep xylitol-containing toothpaste, gum and mints well out of reach, and treat a swallowed tube as a veterinary emergency.
Found in: natural, fluoride-free and children's toothpastes, mouthwashes, gums and mints.
Link to this termZ
Zinc Citrate
Also known as: zinc citrate trihydrate
What it is
The zinc salt of citric acid, and one of the more bioavailable zinc forms used in oral care. Zinc is an essential trace mineral.
Regulatory note
Zinc compounds are used as actives in products presented for breath, tartar control and gum care. Where a product is presented as managing an oral condition, it is a therapeutic good in Australia. We describe products by composition rather than by what they're for.
Trade-offs worth knowing
Zinc contributes a distinctive metallic edge to flavour that some people notice immediately and dislike. It is commonly paired with fluoride in multi-ingredient formulations, so a zinc product is often not a simple one.
Found in: tartar-control and breath-focused toothpastes and mouthwashes.
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