Can I close 2mm gaps between canines and second premolars using dental bonding? (Photo)

Hello and thank you for your question. While the best way to answer this is with an in-person evaluation, the short answer is yes, dental bonding is an option. I recommend getting a formal evaluation with Dentist or a Prosthodontist. A Prosthodontist is a dental specialist who has advanced training in tooth restoration techniques.

You can certainly try. One good thing about bonding is that if you don't like it, you can usually remove it with little or no change to the original tooth. 
I've seen situations like this before where the bonding held up for years. It may not be as strong as your natural tooth, but it does hold up in many cases. Sometimes it can chip or discolor, in which case it may have to be replaced. Also, like with some other fillings, you could get recurrent cavities around them- they must be kept clean and observed by your dentist. 
I've also seen situations where bonding was placed to minimize (not close) the gaps. If you are bonding 2mm you may make the tooth look so wide that it doesn't appear natural. A good compromise may be to bond 1mm, and leave a 1mm gap so as to mitigate the with of both the gap and the tooth- this might be an option for you as well as the gaps behind canines may not be as noticeable as those between your incisors.
Hope this helps!

Yes you can have it closed either with composite or porcelain but you must understand that the two adjacent teeth to the space(canine and the premilar) will end up looking wider than their normal size. Porcelain has a much better color and strength stability and in the hands of the right dentist/ceramist can look better than composite. At the same tome, once again in the hands of the right dentist it can be closed with composite with a pretty good result.