Tick meds with flea/heartworm?

[GSPVIZ]

I use sentinel which is a heart worm/flea oral med.

I need to get the dogs on a tick med since I found 3 on my viz yesterday (1st time).

If I use a tick med which has flea (I think they all do right?), will this be too much since the heart worm includes a flea med?

For now, since I still have 6 months of sentinel remaining, do they make a tick only med that does not have flea meds in it?

Eventually I will switch from sentinel to a heart worm only and then do frontline.

This is probably confusing so I apologize in advance.

[Chaingang]

I've used Frontline plus in the past and it did do a fairly good job. However sometimes they would still attach even if they would die shortly after. This spring I tried a "Preventic collar" which is supposed to last 3-4 months. They claim that it will prevent the tick from attaching and I will admit I didn't pull a single tick from the dogs this spring and summer. I have to confess though, I do not live in a tick invested area and only pulled a half dozen or so off myself all spring/summer.