Many times we run across patients who just love medium or hard toothbrushes because it feels like it cleans better. However, we have found that using a medium or hard bristled brush can actually damage the teeth and cause gum recession, which leads to sensitivity.
When we aggressively brush with this type of bristle we will wear the enamel down to the next layer of the tooth that has very small nerve endings. Gum recession also exposes dentin on the root of the tooth that can cause sensitivity when brushing or getting teeth cleaned. It is recommended we use a soft toothbrush because it removes the plaque debris from the teeth, massages the gums, and the bristles are more flexible to bend cleaning more tooth surface.