Final answer:
The interdental aid made from soft nylon filaments in a cone shape is the interdental brush, which is designed to clean between the teeth where a regular toothbrush can't reach.
Step-by-step explanation:
The interdental aid made from soft nylon filaments formed into a narrow cone shape is the interdental brush. Unlike traditional dental floss, which is a thin strand of twisted plastic filaments or nylon, an interdental brush is designed to clean between the teeth. The soft nylon bristles of the brush are arranged in a cone shape to effectively remove plaque and debris from the spaces that regular toothbrushes might miss. Nylon's use in dental products dates back to 1938 with the first nylon-bristled toothbrush and nylon-6, another type of nylon, is derived from a monomer called caprolactam.
Answer: 2) Interdental brush