Black cavity and hole signifies that it is a dental caries lesion. Without an IOPAR we cannot determine the extent of caries even though there is no pain. There are lots of options to choose from depending on the tooth involved, surface of tooth involved and the extent of caries involved. If front tooth is involved and there is no pulpal involvement esthetic composite restoration can be done. If the caries lesion is close to the pulp and pulp vitality test is positive, Indirect pulp capping can be done. If back tooth is involved and the surrounding surfaces of the tooth are intact and there is no pulpal involvement you can go for Cement or composite restoration. If the cavity is present between two teeth involving both of them without pulpal involvement amalgam and composite restoration is advised. If there is pulpal involvement of the tooth RCT has to be done followed by a crown. Hope this clears your query.
Next Steps
Refer to a General dentist, if needed he'll consult a specialist.
Health Tips
Get a general checkup done every 6 months. Spot black specs early and get it filled to avoid extensive restorations. Get fluoride applications done to prevent Dental decay.Prevention is always better than cure.