From Biologic Width to Biologic Belt: A Three-dimensional Conceptual Framework for Supracrestal Tissue Attachment

Background The concept of biologic width has long been used to describe the supracrestal soft tissue dimensions surrounding natural teeth and to guide restorative and periodontal procedures. Traditionally, this concept has been interpreted as the vertical dimension of the junctional epithelium and supracrestal connective tissue attachment measured from the alveolar bone crest. Conceptual Gap Despite its clinical utility, biologic width has traditionally been interpreted primarily as a vertical linear measurement, which may not fully emphasize the circumferential three-dimensional organization and biological function of the supracrestal tissues. Proposed Concept This article proposes a novel conceptual framework, termed the biologic belt, that complements the established concepts of biologic width and supracrestal tissue attachment (STA) by emphasizing their continuous, circumferential, and three-dimensional protective organization. Beyond its geometric description, the term “belt” highlights the protective role of this tissue complex, a three-dimensional biological barrier safeguarding periodontal tissues against mechanical, microbial, and restorative challenges. Clinical Relevance Reconceptualizing the supracrestal tissues as a biologic belt may facilitate clinical decision-making by providing a biologically meaningful three-dimensional framework for restorative margin placement, periodontal procedures, and peri-implant tissue management.