Toothbrushes should be medium to soft bristle. If they are too hard, they may wear down the tooth enamel. Good hygiene does not require either very hard bristle toothbrushes or a tight grip on the brush. Sometimes, in an attempt to brush well, too much pressure is exerted on the teeth and gum which can lead to gum damage.
Normally, someone who has undergone some type of surgery is advised to use soft bristle brushes as this brush type makes teeth cleaning far more bearable.
In general, hard bristle brushes are not recommended as using them over time may cause changes at the gingival level. Therefore, the best choice is a medium bristle. If doubts still remain, then speak to a specialist.

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