brush

[soonseng]

for how long has a brush been in use that would reduce its plaque removing ability up to 30 per cenr than a new one?

[MangoPete]

there are too many varialbes to answer this
How hard has the person brushed heir teeth with it
Is it a soft meduim or hard bristle brush. is it hard bristle or composite.
How long does the user brush for.
Are we assuming a full set of teeth of a human ro a bucktoothed elephant?

[WendyS]

My dentist always tells me to change my toothbrush every three months and to use dental floss regularly. Everybody has a different definition of "regularly" but I think at least once a week is necessary.

[funnywebsite]

You can usually tell if the bristles are not in the same condition as when you bought it.