Dr. Khan performed a routine tooth extraction on me & it was the most painfull dental procedure I've ever had. I've had tons of dental work in the past ,including extractions & I've never had any trouble getting numb w/ Novacaine. After 7-8 injections I wasn't numb at all. Funny thing is my Insurance paid for Novacaine, but not "gas" & he kept insisting I let him use the gas. When I refused he proceeded to pull my tooth. It was not only painful, it left me w/ a bruised & swollen jaw. I missed 2 days of work & looked terrible for a couple of weeks. I also thought he was very rude & inconsiderate.