Dentist confirmed what I suspected. Won't return my calls now.

Went in for a routine cleaning. Dr. N— (won't name, don't want trouble) does the X-rays, comes back, sits down, and says 'this is unusual, have you had reconstructive work?' I said no. She looks at me for a long moment. Then: 'this tooth structure has a secondary enamel layer I've only seen in — nevermind, I need a second opinion.' She left the room, didn't come back. Hygienist finished the appointment. I've called four times. She's 'unavailable.'