The biggest advantage of the DIY or "do it yourself" method is, without a doubt, convenience. When you whiten your teeth on your own, you do it according to the schedule that works best for you. There aren't any appointments to make and no time is wasted waiting for the dentist. But you will have to wait longer to see results.
There are two types: 1) Dental office tray whitening and 2) Store bought whitening For dental office tray whitening, your dentist must first create custom trays for holding the teeth whitener gel or paste. The tray will conform to your teeth and help keep the whitener in place which you use on your own at home at your convenience. The tray also helps keep saliva from diluting the whitener.
The tray system tends to have slightly less concentration of bleaching agents than the in-office whitening but still require the professional's analysis. Because of the higher concentration than store bought kits, it will whiten your teeth faster and better, but cost a little more.
For store bought whitening kits, there is no professional oversight, so they have a low concentration of bleaching agents. Because of this, at-home whiteners do not work as fast. Instead of seeing results after the first application, when you whiten your teeth at home you may have to undergo several applications before you notice any lightening of your teeth. You may even have to wait several weeks before your teeth lighten to the desired shade. If your teeth are whitened at all.
Also, the store bought one in more flimsy and do not whitening all your teeth at the same time.
If you decide you go the DIY route, you'll find teeth whitening products designed for daytime and nighttime use. Just choose whichever is more convenient. Some brands include choose whichever is more convenient. Some brands include trays for helping to keep the whitener closer to the surface of your teeth. Other brands use strips to keep the whitener in place. There are even pen-like applicators that allow you to "paint" whiteners onto the surfaces you want whitened.
If you do choose to do it yourself, the most important thing to remember is to ALWAYS follow the manufacturer's directions exactly. Doing so is the only way to lower your risk of damage and achieve the results you desire.