Final answer:
Basic dental insurance is the category that would cover the filling of cavities.
Step-by-step explanation:
The dental insurance category that would cover the filling of cavities is Basic dental insurance.
Basic dental insurance typically covers routine dental care, such as check-ups, cleanings, and fillings. While comprehensive dental insurance may also cover fillings, it often includes additional coverage for more extensive procedures, such as crowns or dentures. Major dental insurance usually covers more complex procedures like root canals and oral surgery, while orthodontic dental insurance specifically covers orthodontic treatment like braces.