This series has mostly gone off the rails. There are way too many characters for such a short book, so everything is surface-level, and the action is pure chaos, with lots of unanswered questions that have remained unanswered for too many volumes. I'll keep reading, but this is nothing like the previous books in the series in terms of their character development, humor, and creativity.
Also, parents need to know that this book is only suitable for children who find a fear of dentists funny and ironic. The dentist villain looks and sounds like he's straight out of a horror movie, so if a child is fearful about going to the dentist, this is probably one to skip.