Run Spanish as its own campaign, not a translated ad group
Translated ads bid on translated keywords, and translated keywords are not what people search.
Patients in this county search using the vocabulary of the country they learned dentistry in. The Spanish keyword set has to be built from scratch by someone who speaks it, not produced by running the English list through a translation tool. Match types behave differently too, and close variant logic will pull in terms you did not intend.
Separate campaigns give you separate budgets, separate bids and separate reporting. That matters because the two auctions do not usually cost the same, and you want to see it rather than have it averaged away inside one blended figure.
Negatives need building twice. On the Spanish side, expect to exclude free clinic searches, dental school searches, job hunting terms and study queries, all of which arrive with different wording than their English equivalents.
One rule to hold to: never run a Spanish ad into an English landing page or an English phone greeting. You have paid for the click and then broken the thread at the exact moment the patient decides whether you are for them.