Dental: which may be best to start with - whole mouth teeth whitening session in dental chair or the first ever periodontal visit to determine if there if any perio pocket gum issues to address? some pros and cons for one in 60's?

Perio First: Start with a clean, healthy mouth before embarking on cosmetic procedures.

Order of treatment: Priority is to first eliminate infection, whether gum infection, tooth infection, or both. Infection can damage other organ systems. Once infection controlled, for example elimination of pockets, then cosmetic procedures can be safely and competently accomplished.