Plan to centralise dental clinics on the Uists
Three dental surgeries on the Uists could be closed and the services relocated to Uist and Barra Hospital on Benbecula.
NHS Western Isles said the move would modernise the service.
It also faces high costs bringing the surgeries in Lochmaddy, Liniclate and Lochboisdale up to modern standards.
Local councillor Ronald Mackinnon has criticised the plan saying that for some people going to the dentist would involve a 70-mile (112km) round trip.
He described the proposal as "unacceptable".
NHS Western Isles said communities would be consulted before any decisions were taken.
It said relocating the dental services to the hospital had advantages.
In a statement, it said: "This could reduce professional isolation, improve recruitment and retention, reduce multiple running costs and the costs of instruments, and provide enhanced opportunities for staff development and training.
"Within the current dental clinics, renovation would be required to meet current standards - in particular Lochboisdale Dental Clinic, which requires significant renovation.
"All current clinics offer little scope for any increase in size of clinical accommodation to meet standards. Centralising the service would enable NHS Western Isles to provide high quality services from one location, with scope for future improvements."