dental malpractice

I had a very back experience with my cosmetic veneers. On Jan 21, 2002, a dentist performed veneers to my 5 upper front teeth on Janually 21, 2002. Because his negligence and malpractive, I suffered substantial pain, gum bleeding and swelling (face swelling too) and severe infection which lead to root canals to those 5 teeth within 2 weeks. In just 2 monthes or so, one of the veneers was chipped and after one year, another veneer came of 4 times. Could you give me more suggestion on how to deal with such things? Do I need to hire a lawyer? Thank you in advance.