This is a decent dentist. Tel: 043-350-4618. Open M-F 9am-1:30pm, 3-8pm, and Sat 10am-2pm. He can speak enough English to communicate. Very good pain management, with hi-tech equipment. Also very cheap (compared with UK). Highly recommended (speak to Hamish for more info). Website (Japanese) below:

http://www.ishii-dc.com/

NB It is located on the elevated walkway level next to Tokyo Kaijou Bdg (on the station side), and is opposite a Lawson convenience store.