A Pain in the Tooth | Say Cheese

S4 E110: Luna's family is visiting India. When Jupiter loses his toothbrush, the trio is surprised to find that some cultures use twigs as toothbrushes! It gets them wondering, why do we brush our teeth? And what are cavities Going through some of Dad's photos for work, the trio gets to wondering, how do cameras work? They decide it's time for a scientific investigation.