In this issue of Evidence-Based Dentistry we take a look at two new evidence-based guidelines that have been produced by the Canadian Collaboration on Clinical Practice Guidelines in Dentistry (CCCD). The CCCD is a national, autonomous organisation responsible for the development and maintenance of clinical practice guidelines for Canadian dental practitioners, a group we have highlighted in the journal before.

The group is, to my knowledge, unique, in that it is the only evidence-based guideline group specific to dentistry. Other guidelines groups have produced evidence-based guidelines for dentists, such as those produced in the UK by the Scottish Intercollegiate Guidelines Network (SIGN) on third molars1 and caries prevention in 6- to 16-year olds,2 or by the National Institute of Clinical Excellence (NICE) whose guideline on dental recall intervals is to be finished later this year. Groups such as NICE and SIGN cover the whole healthcare field, and within these groups dentistry has to compete with other interests in order to see the development of guidelines. With the CCCD this is not the case. A second unique feature of the CCCD is that the organisation is funded by a levy on each Canadian dentist.

The new Canadian guidelines are of particular interest because they cover two familiar dental issues, acute apical periodontitis and acute apical abscess. A common thrust in both of these guidelines is to move practitioners away from prescription of antibiotics for these conditions in all but a minority of cases. Since antibiotics are of limited benefit here, the focus is on the use of the appropriate analgesics where a prescription is required. It is because of this that we are drawing our readers' attention to the Oxford League Table of Analgesic Effectiveness, reproduced in this issue. This very useful resource is often overlooked by dentists — a pity, since many of the studies used to compile the systematic reviews on pain that inform the Table are undertaken using the third molar as the pain model. As a result the conclusions are particularly pertinent.

There is a good deal of misunderstanding about guidelines and to my mind this is related to confusion between the terms guidelines, protocols and standards. A guideline is a statement or rule that serves to guide conduct in accordance with policy. It is not, however, a rigid constraint on clinical practice. It is a concept of good practice against which the needs of the individual patient can be considered. In contrast, a protocol is a rigid prescription or observance of precedence so that, for example, if the diagnosis is ‘X’, then you should do ‘A, B, C’. A standard, finally, is a measure to which others conform, perhaps a minimum standard, or a so-called ‘gold’ standard.

It is important to emphasise here — as they do in the SIGN guideline developers' handbook (www.sign.ac.uk/guidelines/fulltext/50/index.html)—that guidelines are intended as an aid to clinical judgement, not to replace it. Guidelines do not provide the answers to every clinical question, nor guarantee a successful outcome in every case. The ultimate decision about a particular clinical procedure or treatment will always depend on each individual patient's condition, circumstances and wishes, and on the clinical judgement of the healthcare team. Guidelines are important because they help remove variation in clinical practice and improve patient outcomes. They can also assist communication between patient and professional. With the ever-increasing amount of information available today, this communication is important.

There are numerous dental guidelines out there. If you search the US National Guidelines Clearing House (www.guidelines.gov) using the term “dental”, 108 related guidelines are identified, or 232 if you use the term “oral health”. The large numbers often mean that two or three guidelines cover the same topic areas. It is best to focus on the evidence-based guidelines. The two CCCD guidelines examined in this issue are good examples. The Commentary discusses them in light of a well-recognised appraisal tool from AGREE (Appraisal of Guidelines Research and Evaluation; www.agreecollaboration.org), together with some remarks from a dental practitioner.