Since another car's door collided with your vehicle causing the dent this would be a Collision claim and thus the deductible from this portion of your auto insurance policy would apply to a claim you placed for the repair of your car damaged by another party's door.
Collision coverage covers damage to your car when your car hits, or is hit by, another vehicle, or other object. So another car door being opened into your car door would fall under Collision.
Comprehensive coverage covers your vehicle for losses resulting from incidents other than collision (OTC). For example, Comprehensive insurance covers damage to your car if it is stolen; or damaged by flood, fire, or animals.
Depending upon how much it costs to fix the ding or dent put in by the person (vehicle) that did not leave a note or stay around to discuss the accident you may want to see if it is worth placing a claim. If the repair cost to your dented car door is less than your deductible amount for your Collision coverage than you would want to just go ahead and pay out of pocket for the repairs without involving your insurance company.