Burning/Disintegrate geometry using noise

[Mirrage]

I'm trying for 2 days figure out how can create noise that allow me to create smooth noise which wont left any alone pieces in the air like this in attachment. Under you can see screen from houdini where I drawed this what I mean. Using standard noise and delete this deometry is create some floating pieces like this inside red lines. How can I create much smoother transition for noise without this alone parts? This is kind of burning effect and I saw it on sidefx forum but this is to liner for me. I would like do disintegrate pieces from inside but without this floating pieces in the air. Hope someone will understand what I'mtalking about and can give me useful tipe

 

Image: http://imgur.com/a/Tsz5F

 

ps. have problems with adding attachments here so I dont know why but there is error when uploadin images or hip..