Routine dental work and cleaning will not be included in any policy (the same way as spaying and vaccinations aren't). But if it is treatment for a specific problem that has occured, such as an abcess or broken tooth, it may be covered - but this will depend on the T&C's of your policy, as each insurer is different. I'm with Tesco and my policy states:
We will not pay the cost of any treatment to, or related to, teeth or gums unless:
? it is accidental external damage;
? an illness or disease has been proved to have been the direct cause of the tooth or
gum problem
We will not cover any condition or treatment arising as a result of preventable tooth or gum disease.