How should a bristle brush be used?

The correct answer is that a bristle brush should be applied lightly to the tooth surface while revolving at the lowest speed. This method is important because applying too much pressure can cause damage to both the tooth enamel and the gum tissue. Using a light touch allows for effective cleaning while minimizing the risk of abrasion and irritation. Furthermore, operating the brush at a low speed helps to enhance control, allowing the bristles to gently clean the surface effectively without causing trauma to the dental surfaces or surrounding tissues.

The other options suggest techniques that would likely lead to improper use of the brush. For instance, pressing firmly against the tooth surface could create abrasions and weaken tooth enamel over time. A vigorous motion may not only be uncomfortable for the patient but could also lead to gum recession and other oral health issues. Lastly, limiting the use of the bristle brush to soft tissues is inappropriate, as bristle brushes are specifically designed for cleaning hard surfaces such as teeth, and should not be used in the same manner on soft tissues.