Treatment For Bruise On Lip After A Hit From Ball

My son got hit by a baseball on the mouth about a week ago. His teeth hit his lower lip and a bruise formed. As the week progressed, the bruise turned white - like a white scab. It fell off and it hurt him. It has since been causing him a lot of pain and the scab has formed again. What should I do for him besides giving him Motrin and applying ice? He is 12 and about 85 lbs.