You can buy extra strength ora-gel over the counter at any decent pharmacy. It's specifically for tooth pain and will help numb the area.
Also the pain in best approached with a combination of painkillers. If it's particularly bad take codeine based products and alternate them with the painkiller that's not in the combination. For example, co-codamol can be taken alongside ibuprofen. Also, it's best to alternate and take a dose every 2 hours to keep on top of the pain (but still leaving the 4 hour gap between each drug dose).