It is customary to measure the color of the teeth (before and after whitening procedure) in a scale measuring the shade of the teeth.
A full shade guide will have 16 shades arranged from light to dark.
Teeth whitening will usually result in a change of 2-7 shades.
We recommend that for good results get yourself a product with 4-7 shades change.
Whether you are looking for a home use teeth whitening kit or at the dentist teeth whitening, solutions are abounded.
In this article you will find the available home use remedies including tips on where to find free teeth whitening samples.
In office solutions will not be reviewed in this article.
OTC teeth whitening product: The cheapest and most convenient teeth whitening option.
Today it is safe to say that OTC products are highly effective when following instructions.
In a nut shell, OTC products are whitening gels with a varied Carbamide Peroxide concentration usually between 10%-40% (Higher concentrations give faster results but not necessarily better results).
The advantages of the home whitening remedies over dentists' treatments:

• cost effective- Home whitening kit price range from 10$ -100$ (you can also find coupons for a free trail or at heavy discount sample kits)
• Convenience- you can use the products at your most convenient time; use it for a long or a short time.
  If you are using the pen applicator you can carry it with you and just apply it after meals to prevent new stains from appearing.
  
• Long term effectiveness - It is agreed by professionals that the only way to maintain white teeth is by using the home whitening kits repeatedly (recommended every 4-6 months).
  

There are 3 different ways to apply the home whitening gels:

1. Pen Brush on Whitener- the most comfortable way for teeth whitening.
   
2. Trays (one size fits all)- the most efficient products
3. Whitening strips

Trays The Most Efficient products (dentists use custom fit trays for patients' home use).
OTC Tray products are one size products.
Not as comfortable as pen applicators but results achieved close to perfect and better than other products.
Trays are recommended for people who want to achieve an excellent results and are willing to put a little more effort to their whitening procedure.
Pen Brush on Whitener These products are alternative to whitening trays and strips.
More comfortable, hassle free teeth whitening.
Since pen applicators are easy to carry and applying them is easy, they are also great as "instant" anti stain products that can be applied right after eating or drinking.
The Carbamide Peroxide concentration varied.
For best results, it is recommended to use products with20%-40% concentration.
These products are perfect for people with relatively white teeth or with yellow stains, people with darker stains should consider tray whitening products.
It is very common to find free teeth whitening samples.
Whitening strips Flexible stripes coated with whitening gel.
The strips are less effective than trays for removing between the teeth stains and are unsuitable for crooked teeth or teeth with big gap.
Some strips are too short and not covering all the teeth.
In addition the strips are not comfortable and tend to slip and slide.
Unless you are already using one of the white stripe products and satisfy with the results I recommend starting with other cheaper products.
Try a free trail offer (a rule of thumb, companies with free trail offers will usually have an effective product) and see if it works for you.