The question of whether the residual root needs to be extracted needs to be evaluated. If the amount of remaining residual tooth tissue is more than 2 mm above the gingiva and the root length is sufficient, the root can usually be retained, by means of retention, i.e., root canal treatment, which may be followed by a pile crown restoration. For the other case, where the retained tooth tissue is clinically observed to be less than 2mm above the gingiva, then if the root is assessed to still have sufficient length, a crown lengthening procedure may be performed to clinically extend the crown length for restoration. However, the retention situation is not absolute, and extraction is recommended for residual roots that cannot be clinically assessed as retention may cause some subsequent problems, such as apical, periodontal, and pulpal diseases, which are detrimental to health.