What You Should Know About Getting Your Teeth Bleached

Everybody wants a nice smile. We want whiter teeth more than ever. But you should be aware of certain things before getting started with the process:

a) Bleaching agents make your teeth microscopically porous, since it is bleaching the stains out. Therefore, your teeth may get hypersensitive to cold. This can be a major problem if you already have a few fillings in your mouth and if you get the instant bleaching done that uses a higher concentration of the active ingredient.

b) You cannot change the shades of Porcelain veneers, crowns, bridges and the resin (white) fillings. So, the natural teeth will get lighter in shade and these restorations then look darker. If you are to get both bleaching and any of these restorations done, get your teeth bleached first and then match the restoration to the newly achieved shade.

c) Because it makes the teeth porous, it may compromise the bonding of the resin restorations. These may come loose or start to leak underneath.

d) There has been some talk about the probable risk of fracture of teeth because of the bleaching agents. But it still needs to be determined through research and clinical trials.

e) Once you're done with the bleaching, it is better to use fluoride toothpaste to ensure caries prevention.

f) Because the bleaching leaves the teeth porous, it will be very easy to pick up stains again. So, if you're not meticulous about your oral hygiene, it will soon get darker. You cannot let tea, coffee, soda or any food with coloring sit in your mouth for long. Brush, floss and rinse. Smoking will be something for you to avoid.

g) If you're using the take-home kit with the gel, do it after brushing and flossing right after dinner. Make sure you do not overload the tray. If you think that the more you'll use, the quicker will be the result, you're wrong. The trays are made with a small bulge as a reservoir, where you're supposed to place the gel for individual tooth. If you put too much, it will get pushed out as soon as you place the tray in your mouth. You will run out of the material very quickly.

h) Once the material gets smudged over your gingiva, it will cause severe inflammation of the tissue. You have to wipe it off right away.

i) If you experience unbearable discomfort even after following these instructions, you should discontinue right away. Some people get good results by doing it every other night. If it still bothers you, use the whitening strips with a lower concentration of the active ingredient. Unfortunately, by then you'll get stuck with a hefty bill because your insurance will not cover the cost.

j) Do not overdo it. Once you have reached the maximum attainable result, there is a plateau effect and then the teeth become translucent. At that point the shadow of the oral cavity starts to show through and your teeth begin to look darker.

k) You may not even need to get your teeth bleached. The perception of the shade is only a relative thing. It has more to do with your complexion. If you are fair, your teeth will always look kind of yellowish. But if you have darker skin, teeth with the same shade will look pearly white!

Some research findings:

i) Bleaching enamel with Carbamide Peroxide could significantly reduce its Ultimate Tensile Strength (UTS) within a 14 days treatment. Therefore, making it brittle.

ii) Non-vital bleaching treatment with sodium perborate may adversely affect shear bond strength of composite resin (white filling) for both enamel and dentin. Similar effects can be expected from 37 percent carbamide peroxide bleaching agent on enamel but not on dentin bonding strength. The use of water/alcohol and acetone-based adhesive systems cannot reverse the effects of bleaching treatments on bond strengths.

iii) The shear bond strength of composite resins is significantly reduced after enamel bleaching for 24 hours.

iv) Reduction of resin-enamel bond strength in bleached and etched enamel is likely to be caused by a delayed release of oxygen that affects the polymerization of resin components.

v) Results of Electron Microscopy study showed that surface porosity increased slightly after bleaching.

vi) The use of the Potassium Nitrate plus fluoride dentifrice (Sensodyne), two weeks prior to and throughout bleaching, may be a useful adjunct for the management of sensitivity caused by professionally dispensed bleaching products. With the bleaching-induced tooth sensitivity, those patients in the Potassium Nitrate plus fluoride toothpaste group were significantly more satisfied with their whitening experience and willing to repeat the bleaching treatment.

vii) The in-office bleaching agents (the quickest of all methods for bleaching teeth) are available if those are something you are looking into. The concentration of the bleaching agent is high and the overall result is very quickly achieved. Some people can experience a higher level of the adverse effects that have already been mentioned.

References:

1. Surface changes and acid dissolution of enamel after carbamide peroxide bleach treatment. Oper Dent. 2005 Jul-Aug;30(4):507-15. PMID: 16130872 [PubMed - in process] Yeh ST, Su Y, Lu YC, Lee SY.

121. Peroxide bleaching agent effects on enamel surface microhardness, roughness and morphology. Pesqui Odontol Bras. 2004 Oct-Dec;18(4):306-11. PMID: 16089261 [PubMed - in process] Pinto CF, de Oliveira R, Cavalli V, Giannini M.

2. Brushing with a potassium nitrate dentifrice to reduce bleaching sensitivity. J Clin Dent. 2005;16(1):17-22. PMID: 15974219 [PubMed - in process] Haywood VB, Cordero R, Wright K, Gendreau L, Rupp R, Kotler M, Littlejohn S, Fabyanski J, Smith S.

3. High levels of hydrogen peroxide in overnight tooth-whitening formulas: effects on enamel and pulp. J Esthet Restor Dent. 2005;17(1):40-5; discussion 46-7. PMID: 15934684 [PubMed - indexed for MEDLINE] Pugh G Jr, Zaidel L, Lin N, Stranick M, Bagley D.

4. Effect of peroxide-based bleaching agents on enamel ultimate tensile strength. Oper Dent. 2005 May-Jun;30(3):318-24. PMID: 15986951 [PubMed - in process] da Silva AP, de Oliveira R, Cavalli V, Arrais CA, Giannini M, de Carvalho RM.

5. An in situ investigation into the abrasion of eroded dental hard tissues by a whitening dentifrice. Caries Res. 2004 Sep-Oct;38(5):473-7. PMID: 15316192 [PubMed - indexed for MEDLINE] Turssi CP, Faraoni JJ, Rodrigues Jr AL, Serra MC.