Hi! The metal bands are used to isolate the tooth so it is not contaminated by your saliva and the sealtants have a sterile field to be placed and bonded. That is what the light does.
The teeth have to be clean and dry or the sealtant pops off. Often this is done with just brushing on a liquid and rinsing it off. You may have not realized she did this.
The sealant is a form of plastic and in a liquid form. This is squirted on to the tooth, pulled in to place with an explorer and cured with the UV light. Simple. Takes only 2 minutes at the most. More like 15 seconds with alot of experience.
The light is NOT dangerous, just a higher frequency to cure the bonding material. And I WEAR sunglasses or look away, DO YOU stare at a 150 watt light bulb? The only thing dangerous about the sealtant is stopping the bacteria from eating away your tooth. I only use the metal bands when some one has a small mouth or can not sit still. Most kids will just open their mouths and sit still and I can do all the molars in about 20 minutes tops. I'm sorry about the cuts, she should have used cotton rolls between the bands in your cheek/lips. The "cuts" will be gone in a day. Look at it this way, if you brush, floss and rinse with fluoride everyday and now have the sealants you don't have to ever see her again. That should make you happy. M