It can be hard to keep smiles healthy in rural areas, where dentists are few and far between and residents often are poor and lack dental coverage. Efforts to remedy the problem have produced varying degrees of success. The biggest obstacle? Dentists. Dozens of countries, such as New Zealand, use “dental therapists” — a step below a dentist, similar to a physician’s assistant or a nurse practitioner — to bring basic dental care to remote areas, often tribal reservations.