The occurrence of dens invaginatus, a developmental anomaly, is reported to be 0.04 to 10%. Treatment modalities, such as extraction, endodontic surgery, and conventional instrumentation of the defect and/or the pulp canal, have been reported. Most suggested treatment modalities are based on the assumption that the tissue inside the invagination communicates with the pulp tissue. However, histological studies show that depending on the type of invagination, the entrapped tissue is mostly connective tissue which may or may not contain pulp tissue components. In situations where the invaginated tissue is contamined and yet no communication with the pulp cavity exists, it is possible to instrument and disinfect the invagination without affecting the pulp and sacrificing tooth vitality. Such treatment will be referred to as "root invagination treatment." A case is described where tooth vitality was preserved when only the invagination was treated.