Visual or visual‐tactile examination for the diagnosis of dental caries

Why is it important to improve the detection of dental caries (tooth decay)?

Dentists often aim to identify tooth decay that has already advanced to a level which needs a filling. If dentists were able to find tooth decay when it has only affected the outer layer of the tooth (enamel) then it is possible to stop the decay from spreading any further and prevent the need for fillings. It is also important to minimise the number of false‐positive results when treatment may be given when caries is absent, and improved visual detection methods may reduce such occurrences.

What is the aim of this review?

The aim of this Cochrane Review was to find out how accurate visual classification systems are for detecting early tooth decay as part of the dental ‘check‐up’ for children and adults who visit their dentist. Researchers in Cochrane included 67 studies to answer this question.

What was studied in the review?

Two main visual classification systems were studied in this review: the International Caries Detection and Assessment System (ICDAS) and the Ekstrand‐Ricketts‐Kidd (ERK) system. A third group of visual classifications is reported and labelled as ‘Other’ because the studies did not report what system was used. We studied decay on the occlusal surfaces (biting surfaces of the back teeth), the proximal surfaces (tooth surfaces that are next to each other), and smooth surfaces.

What are the main results of the review?

The review included 67 studies with a total of 19,590 teeth. Some studies reported on more than one type of classification system, this gave us 71 sets of data to use. The results of these studies indicate that, in theory, if the visual classification systems were to be used by a dentist for a routine dental examination in a group of 1000 tooth sites/surfaces, of whom 350 (28%) have early tooth decay:

• the use of a visual classification system will indicate that an estimated 403 will have early tooth decay, and of these, 163 (40%) will not have tooth decay (false positive ‐ incorrect diagnosis);
• of the 597 tooth sites/surfaces with a result indicating that tooth decay is not present, 40 (7%) will have early tooth decay (false negative ‐ incorrect diagnosis).

A diagram of these results can be found at oralhealth.cochrane.org/visual-examination-classification-systems-results-0331c. In this example, visual classification systems produce a high proportion of false‐positive results. Treatment in the absence of disease is likely to be non‐invasive such as the application of high fluoride toothpaste, or oral health advice and guidance from the dentist, but will incur financial cost to the patient or healthcare provider.

We found no evidence from the data collected that the classification systems differed in their accuracy.

How reliable are the results of the studies in this review?

We only included studies that assessed healthy teeth or those that were thought to have early tooth decay. This is because teeth with deep tooth decay would be easier to identify. However, there were some problems with how the studies were conducted. This may result in the visual classification systems appearing more accurate than they really are, increasing the number of correct visual classification results. We judged the certainty of the evidence to be low due to how the studies selected their participants, the large number of studies that were carried out in a laboratory setting on extracted teeth, and variation in results.

Who do the results of this review apply to?

Studies included in the review were carried out in Brazil, Europe, Japan, and Australia. A large number of studies performed the tests on extracted teeth, while clinical studies were completed in dental hospitals, general dental practices, or schools. Studies were from the years 1988 to 2019.

What are the implications of this review?

We observed substantial variation in the results, which is perhaps unsurprising as the use of these classification systems involve interpretation by the user. There is considerable uncertainty in the likely performance of a future study. Further research studies should be carried out in a clinical setting.

How up‐to‐date is this review?

Review authors searched for and used studies published up to 30 April 2020.

Macey  R, Walsh  T, Riley  P, Glenny  A-M, Worthington  HV, O’Malley  L, Clarkson  JE, Ricketts  D. Visual or visual‐tactile examination to detect and inform the diagnosis of enamel caries. Cochrane Database of Systematic Reviews 2021, Issue 6. Art. No.: CD014546. DOI: 10.1002/14651858.CD014546.