This is the report of a case of four upper incisors with multiple internal/external resorptions after a falling accident in the childhood and subsequent violation of the biologic width by incorrect individual coronal restorations. Endodontic orthograde retreatment was performed and mineral trioxide aggregate (MTA) was placed as apical plug and to repair the large internal resorption. In order to re-establish the biologic width, a controlled surgical crown-lengthening procedure was performed. The expression of matrix metalloproteinase (MMP)-9 in the gingival tissue was used as a biomarker for the presence of inflammation in the hypertrophied gingiva. The one-year control revealed the cessation of the resorptive activities and the stability of the periodontium. The choice for a conservative combined treatment was essential in maintaining the affected teeth in an esthetically challenging area.