If you do a google search for "Thank You Letters" you will find some templates. There is no need to rehash your strong points.
keep it short, mention what you liked about there program, wrap it up. Its is more about keeping your name visible than actual thanking.
Here is one similar to what I sent--->changed a little(made more general/less identifiable): Feel free to use it. I'm in so I don't care no mo 🙂
Dear Dr Doolittle
I enjoyed the interview and tour on Tuesday, November XX, and wanted to thank you for taking the time to meet with me. I was impressed with the blah blah blah blah blah as well as blah blah blah.
I am committed to pursuing a career in dentistry and I am willing to take any additional steps that you may advise in preparation for dental school. If there are any questions that you may have please contact me.
Thank you for your time. I look forward to hearing from you.
Sincerely yours
Airventus Maximus