Which is better among dental and ayurveda? How is medical electronics?

All the fields have equal values at the beginning. Thereafter, it depends on how skillfully you utilize their knowledge and apply it where-ever required. So, opt the one which you like more.

Ayurveda has more scope in foreign.

Both have values respective to their fields.

Ayurveda is much better than dental. Medical electronics is also good. It is up to your choice.