Can someone please tell me if doing dead lifts with dumb bells is as good as with a bar. also , do you think it would force you to use better or worse form?
If you use a barbell you're probably using more weight, so theoretically the growth stimulus is greater for the barbell deadlift. But if you find the dumbbell version more accessible, you'll do them more often, which will cause better growth. Pick your poison.
I would think that the barbell version forces you to use better form since there is less variation of movement in barbell vs dumbbell exercises. But you can't afford to be sloppy in either, especially if you're handling more than token weights.