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Twetman1 based conclusions on “an excellent systematic review performed ... to high standards.”2 Unfortunately, Twetman seems no better able to distinguish rigorous reviews from flawed ones than Deshpande and Jadad.2 The reality is that the review was not even close to excellent, nor the standards even close to high. To start with, the conflict of interest is obvious when one author selects his own rating system for trial quality, despite the fact that this rating system has been amply demonstrated to be fatally flawed3, 4 because of its confusing necessity with sufficiency. Yes, randomisation, masking and appropriate handling of withdrawals are necessary, but they certainly are not sufficient, even taken together. There are many other key measures of trial quality that the Jadad score ignores altogether. For example, was the statistical analysis appropriate? The use of the Jadad score spares the reviewer from having to concern himself or herself with such trivialities, and clearly represents an effort to unburden the reviewer from having to do any real work to evaluate trial quality. The result is obvious. Beyond this, the convention that even a Jadad-3 trial is high quality says that these bare-minimum standards are not even necessary; we can compromise on two of them, as if there is some compensation in getting the other three right. Not that they even need to be right. Randomisation, for example, may be completely inappropriate (such as permuted blocks of size two in a trial labelled as masked but clearly unmasked by differential tastes or rates of specific side effects) and still receive full credit. So were there any high-quality trials on which to base the conclusions regarding the impact of polyol-containing chewing gums on dental carries?

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