Which Option is Best - Invisalign or Bonding?
If your teeth are unusually small, it may not be aesthetically appealing to you to simply close the spaces. However, if they are narrow and all of your teeth are also smaller than typical, it may be perfectly acceptable for you to have the spaces closed.
If certain of your teeth are small (such as the front ones) and the others are normal in size, you may want to have your teeth moved orthodontically to prepare for either bonding or porcelain laminates to be placed when the tooth movement is completed. You should discuss all options with your orthodontist.
Veneers or bonding can correct small teeth with gaps
Depending on the size of your jaw, your teeth, and what your bite is like, Invisalign or any other orthodontics may not be the best option for you. Either bonding or porcelain veneers (like DURAthins or Lumineers which are minimal-to no-prep veneers) can both enlarge your teeth and close the gaps all in one fell swoop. Make sure you find a dentist who has had specialized training in minimal preparation porcelain veneers as they can be more challenging for the dentist than conventional veneers or crowns.
Invisalign and bonding would both be suitable, but depends on the situation
The advantage of Invisalign is that you can leave your teeth alone and simply line them up better. However, if your teeth are abnormally small, you still will have small, misshapen teeth that are now lined up nicely and are touching.
Porcelain coverings would be a benefit in that you could give yourself the shape and shade you like, and still have them nicely touching.
A comprehensive exam by your dentist should help you determine what factors to consider in treatment and what course of action would be best to take.
Spaces can mean other things
Often, the spaces can indicate a tongue positioning issue and can be associated with airway problems in later years. Closing the spaces CAN create a problem. Similar to a person that drives a Cadillac and has a garage that fits a Pinto. If your tongue wants space, it needs that space.
You may want to consider porcelain veneers. Similar to your bonding, it can close the spaces but still leave room for your "Cadillac". If done well, they will be smooth and will not catch floss as your current bonding does. Veneers will allow the teeth to be the right size (you state that they are too small) and can be whatever color you desire.
The answer to your question is yes, Invisalign can work. Traditional braces should be considered as well, but a comprehensive exam should be done to rule out other issues.
Bonding vs. Invisalign for small teeth with gaps
If your teeth are too small and there are gaps between them, you are an excellent candidate for no-prep veneers. No-prep porcelain veneers, like UltraVeneers, will give you a beautiful smile that will last a long time. You may also do bonding (chair-side veneers), however the results will not last as long, and the aesthetics may be inferior to porcelain. Consult with an experienced cosmetic dentist to help you decide which route to take.
I have not seen your teeth and a close up photo of your teeth would help a lot. Normally simply straightening teeth that are small can make you look child like.
It is usually better at your age to have bonding done. It is paramount that you have a dentist with cosmetic training do that donding if you want it to look real.
When you are a little older--21 years old or so--veneers are an incredible option.
I hope this helps