I have been reasonably lucky in dentists over the years...two excellent ones, a couple of 'good' ones, and only a couple that I didn't trust.

I am not particularly afraid, but I do have a fast metabolism and a high tolerance for novacaine, so it often takes a bit longer and a bit more to get me numb. My last dentist was over-careful, and hated to give me more, but the current one just says "fine", and makes sure it's ok....

(oh...my last dentist explained that *HE* had never had a cavity, and all the dentistry he ever endured was an occasional cleaning)