Depends on what your budget is. Downtown hotels are quite expensive. If money is no object, The Newbury is your best bet. Set on quite literally one of the best parcels of land overlooking the public garden, Newbury Street, and Comm Ave, it’s got beautiful views and is walkable to almost anything. Exemplary service, beautiful historic luxury property (it was formerly the first Ritz Carlton) with large and beautifully renovated rooms. Boston Park Pkaza is also in a great spot, but offers the option of small rooms (like 160 sq ft) at a reasonable price compared to other hotels in the area. Moxy on Tremont and Stuart is a nice modern hip brand, small rooms but fun atmosphere. Area can be a little wild at night but still safe

I don’t think most if any plans would cover more than 2 since ADA recommends every six months. Most plans would be up to $5k (more for couples or families) and 2 cleanings (some only cover 1 annual visit). If you have an HSA you could use that to pay for additional visits, but you could also check with Tufts Dental School. If you’re willing to be worked on by a dental student, you can get very cheap/free dental care