Thank you for the link. It’s worth mentioning that there are response letters to the publication you linked from other experts, the majority of which are critical and point out misinterpretations and omissions by the author. It’s always good to question, but in this instance it looks like the consensus amongst experts evaluating that publication is still that fluoridation is safe and improves dental health. The response letters can be read here.

Edit to add: The responses include a letter from the dean of the Harvard School of Dental Medicine stating that the publication is deeply flawed and requesting a retraction, and a similar condemnation from the students of the Harvard School of Dental Medicine. The article was given greater weight by being linked to Harvard, but in fact Harvard dental experts explicitly disagree.