Hi,       The earlier a dental treatment is done the easier it is.        Anyway, xray of the tooth and picture is required for a proper diagnosis but with the details given by you I would guess it's a decayed wisdom tooth.         In that case it has to be taken out before it is further damaged.         Hospitals and clinics are taking all necessary disinfection measures and following covid protocols so that patients are safe. So do not worry and visit your nearest dentist for further management. In the meantime, start lukewarm salt water rinse thrice daily and a medicated mouthwash rinse twice daily. For any further details you can consult me online.