RESUMO
A satisfactory understanding of the relationship betweenperiodontal tissues and restorative dentistry is supreme tosafeguard satisfactory form, function, esthetics, and comfortof the teeth and its supporting structures. The tooth and itssupporting structures shall be considered as one biologic unit.Most of the dental surgeons are not aware of the importantrelationship, specific concepts such as biologic width, itsmaintenance and applications of crown lengthening in casesof biologic width violation. In the case of extensive caries,sub-gingival perforation and post and core placement inendodontic therapy, the concept of biologic width gains itsimportance. Biologic width is essential for the preservationof periodontium, which ultimately decides the success ofrestorative procedures. This article reviews the anatomy,categories, evaluation, violation, methods to correct theviolation of biologic width and its relationship to periodontalhealth and restorative dentistry.