The situation in England currently depends on whether you are being treated privately or on the NHS.
Private dentists who have obtained the correct protective equipment and have worked out their safety protocols are now offering all types of treatment. They may or may not be charging higher fees to cover the significant additional costs of keeping the surgery open.
As far as I can fathom, and the situation is confused and changing daily, most NHS dentists are not offering any aerosol generating procedures (which is most things in dentistry) and are referring these patients to the so called urgent treatment centers. They are also doing as little other treatment as possible as they are not being paid the additional fees to cover the increased costs of working. They may have 20% of their fees deducted for laboratory based work that is not being done, so they cannot really do any until they are told what the situation is and the NHS has not yet told them. Absolute shambolic situation.
So, if you need any dental work done, either see a private dentist or wait until the NHS has sorted itself out.