Teeth Bleaching: How It Works, Considerations and Cost

Bleaching can irritate the gums, and the effect is usually temporary. The treatment uses a peroxide gel, a bleaching agent that lightens the tooth, and where it touches gum tissue it may leave a white patch or tenderness that normally fades within a day or two. A barrier is usually placed along the gum line during in-clinic treatment for this reason, and take-home trays are trimmed to the shape of your gums. Bleaching is typically not carried out on sore or inflamed gums, so active gum disease is treated first.

A dead or darkened tooth does not respond to gel applied to the outside, because the discolouration comes from inside the tooth rather than the surface. The option used instead is typically internal bleaching, where the agent is sealed inside the tooth and changed over two or three visits until the shade matches its neighbours. It is normally carried out after root canal treatment. If a single tooth has darkened on its own, consult our friendly dentists, who can check whether the root is sound and advise based on the cause.

Bleaching your teeth at home is generally considered lower risk when the trays are custom-made by a dentist, and higher risk with a shop-bought kit. Kits sold directly to the public in Singapore are capped at 0.1 per cent hydrogen peroxide, so they work at a fraction of the strength of dentist-dispensed gel. Uncustomised trays may also not seal against your teeth, which can let gel escape onto the gums and into saliva.

Yes, teeth bleaching gel expires and loses strength over time. Peroxide breaks down gradually, so gel kept past its date may produce little change even when it is used correctly. Warm storage speeds that breakdown, so gel dispensed by a dentist is usually kept refrigerated and meant to be used within the period advised. Check the date before starting a course, and ask for a fresh syringe rather than continuing with an old one.

Signs of over-bleached teeth include biting edges that look translucent or slightly blue, a flat and chalky shade rather than a natural one, and sensitivity that persists for weeks instead of settling within a few days. The translucency happens because enamel is naturally thin at the edges, and repeated bleaching makes it easier to see through. Gums may also stay sore. If you notice any of these after repeated bleaching, stop and see our friendly dentists, who can assess the enamel and advise on what suits your teeth.

Bleaching takes a single appointment of 60 to 90 minutes when it is done in the clinic, with the change visible the same day. A dentist-prescribed take-home kit works more gradually, with the trays worn daily over one to two weeks. A short top-up using dispensed gel takes only one to three nights. Heavier staining may need a second round of in-clinic treatment or a longer spell in the trays, and an assessment beforehand gives a realistic idea of how long your own teeth will take.

Teeth bleaching is generally considered gentle on the teeth when it is carried out under dental supervision. The effects that do occur are temporary: sensitivity for 24 to 72 hours and, where gel has touched the gums, a white patch or tenderness for a day or two. The greater risk comes from bleaching at home without a check-up first, because peroxide reaching an untreated cavity, an exposed root or inflamed gums causes far more irritation than it would on intact enamel.

Bleaching results generally last around 12 to 18 months before a repeat course or a short top-up is considered. It also depends on factors such as how much coffee, tea, red wine and curry you drink, since these return pigment to the enamel faster. Rinsing with water after these limits how much settles in, and regular scaling and polishing removes the surface film that pigment clings to. Your dentist can advise whether a top-up or a full repeat course suits your teeth.

Teeth bleaching in Singapore is priced according to whether it is done in the clinic, at home with dentist-prescribed trays, or as a combination of both. At True Dental Studio, our teeth bleaching options are Whitening Gel Only at $218, Take-Home Whitening Kit (Tray + Gel) at $499, In-Clinic (Philips Zoom) Whitening Treatment at $999, and In-Clinic (Philips Zoom) + Take-Home Whitening Kit at $1,299. A consultation costs $27.25 to $65.40. All prices are nett and inclusive of GST.

Yellow teeth usually respond well to professional whitening. The gel used contains peroxide, a bleaching agent that releases oxygen to break apart the pigment trapped inside the tooth, and yellowing from ageing, coffee and tea is the type of discolouration it handles most predictably. Grey or brown staining from tetracycline antibiotics or a knock to the tooth lightens far less, and existing crowns, veneers and fillings do not change colour at all. A shade assessment before treatment gives a realistic idea of how much your teeth are likely to lighten.

Tooth bleaching is not usually painful during treatment, though short, sharp twinges with cold or sweet foods are common afterwards and normally settle within 24 to 72 hours. The gel temporarily opens microscopic pores in the enamel, making the nerve more responsive to temperature until saliva restores the surface. Using a desensitising toothpaste with potassium nitrate or stannous fluoride for two weeks before and after treatment can reduce this. If pain is severe or lasts beyond a few days, consult your dentist, as it may point to decay or an exposed root.

Teeth do gradually pick up colour again after whitening, though they do not usually return to their original shade. Pigment from coffee, tea, red wine and curry settles back into the enamel over months, so a repeat course or top-up is generally considered every 12 to 18 months. Rinsing with water after those drinks and keeping to regular scaling and polishing slows the change. The speed varies with diet and habits such as smoking.

The downsides of bleaching teeth are mostly temporary. Tooth sensitivity is the most common, bringing short twinges with cold or sweet foods for 24 to 72 hours, followed by gum irritation that shows as a white patch or tenderness for a day or two. Results can also come out uneven, since biting edges lighten faster and existing crowns, veneers and fillings do not lighten. Throat or stomach discomfort is uncommon and tends to come from a poorly fitting tray letting gel leak, which is more likely with a shop-bought kit than with dentist-prescribed trays.

Teeth that cannot be whitened by bleaching gel fall into two groups. The first is anything artificial: crowns, veneers and fillings keep their original colour, so they may stand out more once the natural teeth around them lighten. The second is a tooth that has darkened from the inside after an injury or root canal treatment, which typically needs internal bleaching rather than a surface gel. Teeth with untreated decay or active gum disease are typically not bleached until those problems are treated.

Teeth do get whiter after bleaching, though how much varies with the type of staining. The gel works by releasing oxygen that breaks apart pigment inside the tooth, so discolouration made of pigment it can reach lightens well, and yellowing from ageing and diet falls into that group. Grey or brown staining from tetracycline antibiotics or an old knock to the tooth is bound into the tooth structure itself and improves far less. In-clinic treatment produces the most noticeable change in a single visit, while dentist-prescribed trays work more gradually.

Bleaching is worth considering when the staining is the type that responds to it. Yellowing from ageing, coffee and tea lightens well, and results generally last 12 to 18 months before a top-up. Staining from tetracycline antibiotics or a knock to the tooth improves far less, and bleaching does not change the colour of crowns, veneers or fillings. At True Dental Studio, our teeth bleaching starts from $218 for Whitening Gel Only and goes up to $1,299 for In-Clinic (Philips Zoom) + Take-Home Whitening Kit.

Scaling and whitening do different jobs, so one does not replace the other. Scaling and polishing removes the surface film of plaque, tartar and stain that builds up from food and drink, returning teeth to their natural shade. Whitening uses a peroxide gel to lighten the tooth beyond that natural shade. If your teeth look dull mainly from surface staining, scaling may be enough on its own. If you are unsure which your teeth need, consult our friendly dentists, who can assess and recommend the most appropriate options for your teeth.

Teeth whitening does not appear to damage enamel when it is carried out under dental supervision, and current evidence does not show lasting softening or thinning. The oxygen released by the gel acts on the pigment molecules inside the tooth, not on the mineral structure that gives enamel its hardness. Bleaching does temporarily open the microscopic pores in the enamel, a reversible change that saliva restores over the following days, and it accounts for the extra sensitivity felt immediately afterwards.