Whitening is one of the most requested cosmetic treatments in dentistry — and one of the most confusing to shop for. Strips at the drugstore, LED kits online, in-office lasers, custom take-home trays. Here is what each option actually is, what it costs, and what results are realistic.
How whitening actually works
Whitening gels use peroxide — either hydrogen peroxide or carbamide peroxide — to break down stain molecules inside the enamel. This is genuinely different from surface polishing (what a whitening toothpaste does). Peroxide-based whitening actually changes the intrinsic colour of the tooth, not just the surface.
The two variables that matter are peroxide concentration and contact time. Higher concentration for shorter time (in-office), or lower concentration for longer time (take-home trays), can produce comparable results.
The options, ranked by effectiveness
In-office professional whitening
Cost: $400 to $700 in Calgary for a single session. This uses high-concentration peroxide (25 to 40%) applied by a professional with gum protection, sometimes activated by a light. Results are visible immediately — typically 4 to 8 shades brighter in about an hour. Best for people who want fast, dramatic results, or who are prepping for an event.
Custom take-home trays from a dentist
Cost: $300 to $500. We take impressions of your teeth and make custom trays that fit exactly. You wear them at home with professional-grade gel — usually 30 minutes to two hours a day for two weeks. Results are gradual but typically match in-office whitening after the full course. This is what most dentists recommend for most patients: less shock to the teeth, results that last longer, and trays you can reuse in the future for touch-ups.
Drugstore whitening strips
Cost: $30 to $80. These work — they contain real peroxide, just at lower concentrations than what a dentist would use. Expect gradual, modest whitening over two to four weeks. The main downside is fit: strips do not conform to teeth as well as custom trays, so results are often uneven, especially around canines and molars.
Whitening toothpastes
These do not really whiten in the peroxide sense — they polish surface stains. Fine for maintenance, not for actual colour change.
LED kits and TikTok whitening pens
Mostly marketing. The peroxide concentration is usually low, the LED lights are not doing much, and application quality varies wildly. Some are harmless-but-useless; some contain unregulated ingredients. If you want to spend $80 on whitening, get drugstore strips.
What results are realistic
Most people can expect to lift their teeth 3 to 8 shades brighter with professional whitening. That is a real, visible change — but it is not "Hollywood white." Truly bright, uniform white smiles you see in magazines are almost always veneers, not whitening. Whitening makes your teeth a brighter version of your own natural shade, not a different shade entirely.
Whitening also does not work on existing dental work. Crowns, veneers, bonding, and fillings stay the colour they were made. If you have visible dental work on your front teeth, we will talk through the sequence — usually whitening first, then matching new work to the whitened shade.
Side effects to know about
The main side effect is temporary sensitivity, especially with higher concentrations. Using a sensitivity toothpaste for a week before whitening, and taking a day off between sessions if needed, usually manages this. Sensitivity resolves within a few days of stopping treatment.
Gum irritation can happen if the gel touches gum tissue — this is why professionally applied whitening includes a gum barrier, and why custom trays fit better than drugstore strips.
How long results last
One to three years for most people, depending on habits. Coffee, tea, red wine, and smoking are the main culprits for staining. Most patients do a touch-up every 6 to 12 months using their custom trays, which is why the take-home tray option ends up being the best long-term value.
If you are considering whitening
Come in for an assessment before starting. We check for cavities and gum health (both should be addressed before whitening), we look at whether you have any existing dental work that will affect the result, and we recommend the right option for your specific goals. Whitening is one of the safest, most effective cosmetic treatments in dentistry — but starting it on an untreated cavity or without knowing what result you can realistically get is where people end up disappointed.