You should go to YouTube and watch a Dr Ben Casey video. Click here to see a video. It's a very old series but still good.
When Dr Ben tells a patient about something it is full of gravitas. He really means it.
By contrast, I often hear dentists downplaying what need to be done. They use adjectives like “little” (“There's a little crack in that tooth”) or “quick” (“Let's have a quick look at what's going on”). If Dr Ben were speaking he would never say “little” or “quick”.
When you tell a patient about treatment needed are you dead serious? Does your demeanour let them know you are talking about something that's important?
By all means enjoy your patients and be nice to them but when it gets down to discussing treatment try to be like Dr Ben.