Your trees will be prone to infections and non flush pruning since its a hedge trimmer it will tear rather than cut and will leave your sticks torn and looking like crap... The blades are very easy to sharpen though. A flat file or like a makita grinder. Just look up a youtube. My suggestion is look into silky lopper and pruning saws. Pruning saws are insanely sharp and will make quick work of your twigs you need to cut with less than half a swipe much faster than lopping.
It is very important for you to post your results once the problem is solved so that people will be able to reference a solution to their problem down the road. YEARS may go by and someone has the same problem PLEASE POST YOUR "IT WAS FIXED WITH x SOLUTION.