My record is 5 injections for 1 tooth and it still wasn't numb [help] I'd not slept for 2 days though so she pulled it anyway, told me to hang on and not hit her hehe. Worst bit is the sound, the nice wet crunch when they push and twist the tooth, yummy! Root canal isn't that bad, I had one done 5 years ago and not had any problems with it at all. Probably one of my best teeth.