Hello and thanks for your question! Definitely possible. Gum recontouring and veneers on your upper front teeth could get you a nice correction. Your cosmetic dentist will show you a waxup modelof what your veneers would look and what to expect. It's difficult to tell from just your...
At age 15, I believe you are too young for a traditional veneer, which usually requires some preparation or filing of your natural, healthy tooth. I feel a better option at your age would be cosmetic bonding, if your are able to find an experienced and skilled dentist in this...
The condition of the teeth won't prevent a smile makeover, but some veneers become crowns if the tooth structure is too damaged. Decay must be removed, and the process of veneering teeth often removes the decay, if not then the prep can become more like a 3/4 crown to include the decayed area.