The aim of Lucena’s et al. (1) study was to assess the statistical quality of scientific reports in the field of microleakage of direct restorations in operative dentistry. The category “Dentistry, oral surgery and medicine” in the ISI Web of Science provided 226 scientific articles published in 22 different journals during 2001 and 2009.

Microleakage was studied quantitatively in 50 (22%) articles and qualitatively in 176 (78%). The review showed that the statistical methodology varied considerably for similar experimental designs. Most statistical errors were also found regarding design issues. Of the 226 articles, 175 (77%) had no clear description of tested hypotheses, 224 (99%) had no sample size calculation, 224 (99%) failed to report drop-outs, 162 (72%) failed to use and report blinding, and 197 (87%) did not describe baseline comparability of the studied groups.


1. Lucena C, Lopez JM, Abalos C, Robles V, Pulgar R. Statistical errors in microleakage studies in operative dentistry. A survey of the literature 2001-2009. Eur J Oral Sci 2011;6:504-510.