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The history of the names of chemical substances is worth some study as it reveals the development of chemical thought from the earliest attempts to study the way the world works. Some old forms persist in literary contexts (e.g. brimstone), others are retained in common speech (e.g. acetic acid). The field of chemistry itself has endeavoured to standardize a systematic approach to a variety of areas on a number of occasions since the nineteenth century, culminating in the system of preferred names developed by the International Union of Pure and Applied Chemistry (IUPAC). The point of all this effort, of course, is to be able to communicate exactly, unambiguously, the substance involved. One can understand that the literature will show the progression over time as understanding and rigour develop, and it remains necessary to be able to decode old names. Yet, when perusing a list such as that for EDTA [16], several points emerge. Firstly, the use of trade names as if they were chemically meaningful (v.s. ‘MTA’), when the cessation of the sale of the product would mean that decoding the reference might take some considerable effort in the future (and we have to assume and accept that trade products will at some point cease to be sold). Some products are the same but sold with different labels, such as the Endosequence, Totalfill, and iRoot ranges. Researchers can waste a lot of effort trying to compare these when it is not necessary. Secondly, the import of foreign‐language versions without translation or checking can only confuse. Thirdly, the arcane terms used by manufacturers in their product information might seem intelligible, but you only have to read the ingredients of certain prepared foodstuffs or cosmetics to see how they would leave even a chemist stymied and bemused (part of the reason for the introduction of the E‐number system by the European Food Safety Authority (EFSA)). Fourthly, there are several ways of being systematic. But then, looking at the dental literature, we can discern other problems. Manufacturers wish to obscure their formulations for commercial reasons, but the substance names used commonly convey very little to help understand their chemical, mechanical, or biological properties, such as interactions and allergies – points that have already been made. For these to be parroted uncritically as technically correct labels betrays many things. The fact that there are documented instances of advertising copy‐writers (presumably not chemists) garbling text in the manner we are used to from the press, only for this to be propagated by ‘research’ papers, is at best disappointing. We have a duty to communicate accurately. It is incumbent on us to check. We are obliged to review material critically, and report accordingly. In many cases, a preferable approach would be to identify a substance and state its IUPAC name, then be consistent in using a proper chemical term: the appearance of several names for the same substance in the same text underlines the complete absence of understanding. Reviewers should insist on clarity.

As we should appreciate, all materials used in dentistry represent compromise. It is simply not possible to obtain all desirable attributes (chemical, physical, mechanical, biological, economic, practical) simultaneously. We routinely trade off one thing against another, and accept some deficiency for some other benefit. There are commonly strong grounds for believing that ideality is unapproachable: physics is a hard taskmaster, and thermodynamics ineluctable. Nevertheless, it is proper to enquire as to the amelioration or refinement that might be possible. This should be on rational grounds, not guesswork or wishful thinking. We have seen such awkward proposals before in a number of instances, such as ‘resin‐modified’ glass ionomer cement (GIC). If GIC has some good properties but is weak and moisture‐sensitive, whilst light‐cured materials are strong and insensitive, surely we can do both? No. Firstly, the one function replaces the other: in a given volume, something has to go to make space for something else. All too often, ‘additions’ are made that are not recognized as the replacements they are. Given that, something must be diminished even if something is gained. Secondly, by including competing reactions that have no chemistry in common, the trade‐off depends on the relative rates and timings: it is a very fine balance, the probability of attaining which is low [17]. This is a complicated and messy system that falls between two stools. It is well recognized that ‘compomers’, where a GIC‐type glass was used as the core in a resin matrix, failed to work as hoped [13, 18] – so why now do we see supposedly light‐cured hydraulic silicate cement? Similar arguments apply, similar outcomes are to be expected. The triumph of advertising over substance? Wishful thinking is the bane of dentistry.

We see similar failures of appreciation in the seemingly random selections of additives regularly studied and proposed for many applications. For example, a material is too weak for a certain use, but a strong material is known that can be made as a powder – why not add this? Again, the replacement aspect of such a design is not recognized, but a key requirement of such composite structures is missing: bonding. Composite structures require a bond – that is, a chemical bond – between the matrix and the core (alias the ‘filler’, a term that betrays a less than honourable economic incentive in some contexts) for stress transfer to occur and the benefit to be realized. This is ‘matrix constraint’. With it, there are remarkable improvements. Without it, the material behaves as if it were full of holes, with the obvious outcome. This was seen in the attempts to strengthen silver amalgam with (silver‐plated!) sapphire whiskers, GIC with zirconia powder, and GIC with amalgam alloy powder (‘miracle mix’) to name but three egregious examples. Now we have ‘microsilica’ added to HSC. In fact, we should be careful to distinguish between materials that are included to do a job – such as reactants or bonded core – and those that have no other purpose than to dilute the system, which is all a true filler actually is. Of course, the inclusion of pharmaceutically active substances such as antimicrobials must also be treated rationally, because they are then part of the matrix (occupying volume) and therefore affect all its properties, always – poor discriminatory power experiments notwithstanding.

It is often the case that such an additive will be explored at a range of proportions (and, sadly, when it matters, not accounting for the consequent changes in other, more important, ratios). Then, through the sequential application of Student's t‐test, the maximum amount that does not give a statistically significant result (i.e. a ‘nonsignificant P > 0.05’, ‘N.S.’) will be decided upon. This is fallacious in several respects. Firstly, anything that interferes with the setting reaction or the resulting structure must, by definition, cause a deterioration. Secondly, the ‘failure to detect’ is not the same as an assertion of no effect; it is the entirely expected consequence of the poor discriminatory power of testing with a small sample size, large scatter, and relatively weak effect. Whether it matters is not the focus of attention as it should be, but the claim is made that the addition is safe because ‘nonsignificant’ is enough. In fact, with a large enough sample size, you will always get a ‘significant’ result. In addition, the test is weak because it is piecemeal instead of looking for the covariance of the outcome with input, when the full power can be obtained. It is also wrong because it is trawling without multiple test protection. What is proper is to determine the size of the effect, then determine – from other considerations – how much is tolerable. If reviewers do not understand all this, what hope is there?