Resin composite placed on front two teeth to close a gap. No drilling or filing down was done at all. I also believe acid etching was used. 1) Can this be removed to expose my real teeth again? If so, is it likely they'll be sensitive or much more prone to decay? 2) the back of my front teeth feels like soft sandpaper. No (minimal) composite was placed on the back. Why? From the acid etching? From other materials used? Will this resolve over time? Is this now more susceptible to decay?