Hello dear, 

Both of them are quite good as a career option. 

A programme in Dentistry trains a student in treating people of oral diseases, maintaining their oral health by diagnosis, prevention, and healing of cavities, dentures , gum related diseases. 

Whereas, Agricultural Engineering relates to the science and technology of producing food grains. It applies principles of engineering science and technology to production and processing in the field of agriculture. Here the knowledge of agriculture principles gets combined with the disciplines of animal biology, plant biology and also principles of Mechanical, Civil, Electrical and Chemical Engineering. BE/B.Tech in Agricultural Engineering is a 4-year programme.

I would suggest you too go according to your interest because both of them are good. 

All the best!