Are advertisements in dental journals supported by an appropriate evidence-base?

Dental professionals are constantly exposed to advertisements in the dental literature. These promote products, either for use in the operatory or to recommend to patients. In an era of evidence-based practice, what references are provided to support claims made by the advertisers?

This study aimed to determine if advertisements in four major dental journals, whose target audience is general dental practitioners, were supported by an appropriate evidence-base, readily accessible to readers.

The 2010 printed volumes of the Australian Dental Journal, British Dental Journal, Dental Update and the Journal of the American Dental Association were hand searched to identify advertisements which made a claim of clinical benefit or superiority to competing products. Advertisements were categorized according to type of product being promoted and the availability, nature and number of any supporting references was recorded. Repeated advertisements were analyzed only once.

A total of 390 advertisements were identified and 369 made a claim of benefit or superiority. When the 222 duplicates of the same advertisement were removed, 147 unique advertisements remained. Of these: 54 (37%) were advertisements related to dental devices for in-surgery use; 44 (30%) for dental materials, and 27 (18%) for dentifrices/medicaments. 113 (76.9%) advertisements offered no evidential support for claims made. Of the 34 advertisements that provided evidential support, only 20 provided a complete reference that could readily be sourced by an interested reader: 15 articles in refereed journals; 5 data on file; 3 in-house studies and combinations thereof. Four references were not accessible due to incomplete referencing. Two advertisements provided evidence that was not relevant to the product being advertised.

The majority of advertisements in the dental literature do not provide an adequate evidence-base, readily available to readers, to support the claims being made. If evidence-based practice is to be encouraged, greater emphasis on scientific referencing in advertisements is required.