Not only is it bad for your health, smoking is one of the worst offenders when it comes to staining teeth. Tobacco causes brown stains that penetrate the grooves and pits of tooth enamel. Tobacco stains can be hard to remove by brushing alone. The longer you smoke, the more entrenched the stains become. Smoking also causes bad breath and gingivitis (gum disease), and increases the risk of most types of cancer.
Vicky / Lisa. I am coming in a little late here but you should not experience any staining on veneers assuming they are porcelain. This is a glass like material and does not have the porous finish of tooth enamel (which also does not stain). I totally understand your reluctance though. Charcoal (activated only) can still absorb any form of discolouration and other bio-film from veneers.
Perhaps the intensity of the heat in the professional whitening lights is the culprit? Or maybe your sensitivity and irritation is caused by the caustic breakdown of the carbamide peroxide formula used in tray and gel whitening methods? No matter what the source of the discomfort is, here are some facts to help guide you in making the right choice when it comes to your preferred method of whitening:
Dietary supplements are also available at most pharmacies for people with low vitamin D. Children under 12 months of age need at least 400 IU of vitamin D. Children over 1 year and most adults need at least 600 IU, including pregnant and breastfeeding women. People above the age of 70 may need up to 800 IU of vitamin D. Ask your doctor before giving vitamin D supplements to an infant or child.
Rinse your mouth with water. Rinsing with water after meals or drinking caffeinated beverages will help remove any leftover food or residue from your teeth will help prevent stain and decay.  This method is especially useful if you’re away from home and don’t get a chance to brush or floss after eating. Drinking water throughout the day and rinsing with clean water after meals is the most underrated method of overall oral health.
To figure out how to whiten our teeth, we have to know why they get yellow in the first place. There are several factors that play a part, including genetics, what kind of food and drink you consume, and how well you practice oral hygiene. A tooth is made up of 4 tissues-enamel, which is the strong white covering that protects the tooth, dentin, which supports the enamel and is a hard yellow material that carries nerves, pulp, which is at the center of the tooth and contains blood and lymph vessels, and cementum, which covers the root of the tooth.
To oil pull, simply put a spoonful of coconut oil in your mouth and swish it between your teeth for five to 20 minutes, or add a few drops to your toothbrush and brush it on. Another oral care option is to apply coconut oil to a corner of a clean washcloth and rub it on the teeth. A bonus regarding coconut pulling? Coconut oil has antimicrobial properties, so it’s great for protecting and cleaning your gums as well.