At-home teeth whitening kits often promise to show results within a certain number of days or weeks. You might not take these promises at face value, but after using the product for the period of time which should deliver results, your teeth have rather stubbornly refused to whiten—and may not have changed their colour in any noticeable way. So why are your teeth failing to respond to whitening treatment?

Accumulated Plaque

The trouble with at-home whitening kits is that they suggest that anyone who uses them can expect similar (favourable) results. But when was the last time you had a dental checkup that involved scaling and polishing to remove accumulated plaque from your teeth? 

Deep Cleaning

The buildup of plaque, as well as tartar (calcified, hardened plaque), can grow to cover large sections of your dental enamel. This means that you may in fact unknowingly be attempting to whiten dental plaque—with minimal or non-existent results, because plaque is a bacterial biofilm, and won't respond to whitening treatment. See your dentist for deep cleaning to remove plaque and tartar, after which you can whiten your teeth (or for immediate results, have your dentist perform the work).

Missing Dental Enamel

Another possible cause for your lack of results is that you lack adequate dental enamel coverage. This dental enamel coats your teeth, helping to protect them from decay. But enamel can deteriorate and erode—often due to negligent oral hygiene in the past. Missing dental enamel reveals dentin, which forms the majority of a tooth's actual structure. This dentin tends to have a stronger yellow tint than healthy enamel, and won't react to whitening treatments as the enamel will. You may also be experiencing uncomfortable sensitivity, as without protective enamel, the whitening agent can irritate the tooth's nerve. 

Dental Restorations

Any teeth with deficient enamel will need some form of dental restoration. This can involve a dental crown fitted over the tooth, or dental bonding (a tooth-coloured composite resin) applied to the tooth to create a new surface. Any restoration should be the shade of white you hope to achieve for your whole smile. Other teeth in your mouth with a healthy layer of enamel can then be whitened by your dentist to match the colour of your restoration.

There's definitely an underlying reason that's preventing your teeth from whitening. Chances are that you'll need to visit your dentist to solve this problem before your teeth can be effectively whitened.

For more information on teeth whitening, contact a professional near you.