How big are these areas? Epoxy is brittle. Filling small cracks might be OK but larger voids could be problematic.
Also, make sure it's a thin epoxy that will soak well into the surrounding teak and bond with it.
I like epoxypoducts.com
Tons of good info on what their different products can do plus some good tech support. Plus prices are way lower than others and just as good or better. Every one of theirs is amine free, no blush.