I actually recently contacted Conair about their hair straighteners asking the same question! This was their response:
"Dear Consumer,
Per our engineer, we do not have any appliances that use PTFE or Teflon. Please let us know if you have any other questions or concerns.
Kind Regards,
Consumer Correspondent"
I also asked the same thing in regards to their curling irons as well and received the same response. I would recommend contacting them just in case listing the specific model you have. I'm not sure if that applies to the older models? It took them 2-3 days to get back to me.