Background The internet provides a potentially invaluable source of health education material for members of the public. Objectives This study aimed to investigate the nature and quality of periodontal-related patient information on the world-wide web. Methods The search term "gum disease" AND "patient information"' was entered into three common internet search engines. The top 50 sites identified by each search engine were downloaded and assessed for authorship, content, accord with accepted dental practice, currency, and references to peer reviewed data. Results The search term returned in excess of 3,615 hits across the three search engines. Of the top 150 identified, 68 were deemed relevant to patients seeking information on periodontal disease. Of these, 17 were duplicated either within or between search engines, therefore the following analysis is based on the remaining 51 sites. The majority of sites (25) were authored by individual dental practitioners, with sites originating in the USA predominating (80%). Information on the aetiology, signs and symptoms, and treatment options for periodontal disease was provided by 38, 38, and 29 sites respectively. This information was deemed in accordance with conventional periodontal practice in 27, 33, and 23 cases respectively. Only seven sites indicated the currency of the information and five provided peer-reviewed references for further reading. The rank order identified by the search engines meant that sites providing comprehensive and authoritative information, were not readily differentiable from sites whose primary objective was promoting attendance at specific dental practices. Conclusions Judicious and active support from professionals is required to aid patients' interpretation of the information identified and to direct them to the most instructive sites.
