Sahni focuses exclusively on root canals, as far as I can tell, and he does a very good job. I had a root canal done back in the '80s, and I'm telling you: the technology and the process these days is much improved. Sahni really seems to know his stuff. He's very careful, in my opinion, and detailed oriented.
I'd give him five stars instead of three if his assistant didn't take so many damn x-rays. For every slide she ended up taking two x-rays: the first one was always screwed up. So my thyroid got blasted with radiation due to her incompetence, which is something I did not appreciate.
I'd definitely go to Sahni again if I needed another root canal. He does a quality job.