What is benefit of an extra soft tooth brush for adults?

They clean better. Soft toothbrushes clean better and won't damage exposed roots. The bristles of soft tooth brushes are able to bend and get into the nooks and crannies of your teeth and gums. I you have any root exposed, soft tooth brushes won't damage the root as will medium or hard brushes.
Less trauma to gums. A extra soft brush will remove the plaque but is less likely to damage exposed roots or the gingiva (gums). An electric brush with a soft head is your best bet for exceptional cleaning with low incidents of trauma to teeth or tissue.

Related Questions

Where can I buy a battery soft tooth brush from?

The store/interent. Any store that has home dental care products should have some of them. There are less expensive nes, but my favorite are any brush that has a 2 minute timer on it. The timer, in my humble opinion, is the greatest advent in home care in years.
Phillips Sonicare. I would highly recommend phillips sonicare electric toothbrush. I think you can get them at wal-mart, target, or online. Some dentists sell them in their office. The sonicare is more expensive than some of the others, but they are great and will last for years.

Best soft tooth brush on the market is which one?

The one you like. As long as you choose a soft bristle toothbrush, there is no better brand over another, in my opinion. Choose the one that you like the most so that you will want to continue brushing regularly!
Phillips sonicare. The best toothbrush in my opinion is the phillips sonicare electric toothbrush. I use one and it is amazing.
The one you use. The best toothbrush (soft or extra soft) is the one that you will use on a consistent basis to perform daily home care at least twice a day. The technology involved in manufacturing has come very far so that most all companies have a really good brush. Electric models do provide some assistance to those with poor manual dexterity and can vastly improve oral hygiene in these cases.
Toothbrush. If the brush makes it into your hands, and you use it for the appropriate amount of time, that is the best brush. You can certainly spend a little extra for the sonics, but people, myself included, have done well for yrs without. Full disclosure I did get one electric (cant remember brand), and imo, my mouth felt cleaner, not that I had any issue with use of the manual..

Does any dentist recommend a soft tooth brush?

Over a hard and medi. The harder the bristles the greater the possibility of tooth brush abrasion if technique is not excellent. The crub the tooth mentality will even allow a soft tooth brush to cause abrasion. The high end mechanical brushes have a vibrational aspect to them that actually provide a benefit over hand held tooth brushes. In addition, the high end mechanical brushes usually have a 2 minute timer.
Of course. Think of your teeth as the surface of a fine sports car. You wouldn't scrub that with an abrasive hard brush would you? Or your fine china with something abrasive? The action of the tooth brush against the "sticky" plaque is the most important. Take your time. Make sure you brush each tooth long enough to remove the plaque. A soft tooth brush is definitely better than a medium or hard one.

Can you recommend a super soft tooth brush for sensitive teeth?

Sensodyne & others. Sensodyne ultra sensitive extra soft toothbrush is one example, but most of the major brands (j.Butler and oral b for example) also have extra soft brushes.
ORAL-B. Oral b tooth brushes have a number of soft brushes to choose from. Use sensydyne tooth paste.