Hi, Can the two front teeth be filed down to the same length? (photo)

You want your 2 front teeth to be the same length, but you have to maintain attractive proportions as well. Your front teeth are a little square, and if you shorten them, the aesthetic result will not be good. However, if you lengthen the teeth with cosmetic bonding, you can have a fantastic result. Ideally, you would bond your 4 front teeth, and your smile will appear near perfect. 

I'm glad that you reported a positive experience with Invisalign, as it is a relatively limited system. Since I can't see a full photo of your front 6 teeth, I can't give you a 100% complete opinion regarding evening out your teeth. Assuming that they're in a reasonable position and have a good size ratio, it is possible to lightly file down the teeth to match. However, what I do notice is that one of your teeth exhibit more wear than the other, which could be why they look uneven; if this is the case, it is probably best to leave them alone and tout your individuality. There is a certain amount of attractiveness attributed to slight asymmetries! Depending on the amount of tooth that would need to be shaved, you could benefit from simple composite bonding or a prepless veneer-- but the amount of tooth structure that you are asking about is so minute that I don't believe that these are worthy investments to look into.