What is the difference between trifexis and sentinel?

Right now I use Sentinel for my 3 dogs but my vet just started caring trifexis. Is one preferred over the other and do I need any additional meds such as frontline if I switch to trifexis?

Trifexis contains Comfortis, which kills the fleas. Sentinel is like a birth control, it doesn't kill the fleas, it sterilizes the eggs from hatching. You wouldn't need any other applicants if you go with the Trifexis, that has flea and intestinal parasite medications. If you have a tick problem around your home, you might want to consider Frontline Plus. If you go on Frontline Plus however, you would have to look into a intestinal parasite medication also. Hope this helps!