The concept of biologic width forms a basis for successful peri-implant soft tissue integration around titanium implants. Therefore, the objectives of this review are to determine and critically evaluate the present knowledge about biologic width around implants and to establish future research trends.The literature was selected through several electronic databases, as well as a manual search in the major dental implant, prosthetic and periodontal journals. The reviewed data was published in English from 1980 to December 2007. Questions for systematic review were formulated. Abstracts, chapters from books, and unpublished materials were excluded, as they do not meet criteria for evidence-based studies. Articles were prioritized according to the value of different study types on the same issue. In vitro studies and literature reviews were excluded. The included publications were clinical, human histology and animal studies.In total, 75 articles were obtained. After two rounds of evaluation and criteria application 54 papers remained for final appraisal, namely 2 clinical papers, 8 human histology and 44 animal studies were analysed. Twenty-one full-text articles were excluded.Evidence analysis shows that the present knowledge about biologic width around implants is mainly derived from animal studies and that clinical controlled human studies are insufficient.