one more thing..if you have "tooth colored fillings".. in the front teeth in your mouth that show; when you smile....... otherwise known as composite fillings.. these fillings to be put in properly are to "blend" in with the shade of your teeth.. and Whoops if you DO bleach your teeth, and they DO lighten guess what??..yuppers.. the plastic composite does NOT lighten so then these fillings are darker...and show up.. and darned if the only way to get them lighter to then match your newly bleached teeth??..
..you guessed it.. to replace the composite fillings again with lighter shade material to match your lovely newly bleached front teeth..
and if you have permanent crowns/ veneers.. on front teeth.. they do NOT lighten either.. that is tooth colored baked on color to crowns... and that is a permanent shade too.., so you have to consider that with bleaching teeth.....they stay the same.. the other teeth lighten with the bleaching process...=shrug...it means choices...
bleaching teeth with trays MADE at a dentist most times does work, takes 90 minutes a day for 2 weeks.. and you can drop a ton of shades from tea, coffee, red wine, and the worst culprit of all.. nicotine stain from cigarettes..BUT... teeth are absorbant.. so if you pick up any of these habits .. and consistently expose your teeth to them.. they will need "touch ups", after bleaching them...and you can indeed "relighten "..them with another bleaching catch up...but it is a good method to use.. and it truly does work.. for a lot of folks.. not to say you'll have a perfect Mariah Carey smile..( BTW..hers are veneers..!!think lee press on nails on TOP of her original teeth..:grin.. ).but the time, effort, and money deters a lot of folks.but the results often times are worth it!!. Happy bleaching gang.!!.:daisy..Joanne..