Design A telephone interview survey of health authorities and health boards.

Setting United Kingdom.

Subjects 104 health authority contacts, usually consultants in dental public health, dental advisers or others in a position to describe the local dental service arrangements.

Results At weekends, 25 authorities have no formal dental care arrangements for unregistered patients, 55 have separate arrangements for registered and unregistered patients, and 44 have 'universal access' arrangements - for anyone in an area, regardless of their registration status. On weekday nights over two-thirds (82/124) of UK health authorities have no formal arrangements for unregistered patients. Where there are separate 'safety-net' services intended for unregistered patients only they are usually (in 48 of 55 authorities) emergency treatment sessions. A fifth of authorities reported planned changes to their local out-of-hours arrangements, including the introduction of telephone triage, and moves to make care available at more times, to more people or from centralised premises.

Conclusions There is extremely wide geographical variation in the organisation of out-of-hours dental services provided in the United Kingdom. In many parts of the UK there are no formal out-of-hours care arrangements for unregistered patients, even at weekends. This unequal provision will mean inequitable access for many unregistered patients. With increasing demands from a growing unregistered population, and various government initiatives to make primary care services more integrated and accessible, the highly fragmented pattern of provision in many areas may no longer be acceptable.