Reading the evidence for oral prevention

Define the question before searching

“Does this product work?” is too broad. For an educational discussion, ask: for whom, compared with what, for which outcome and over what period? For example: “In adults with inflamed gums, does adding an interdental brush reduce inflammation compared with toothbrushing alone?” That question does not automatically answer whether the same tool prevents decay in children.

We offer a way to prepare a short analysis for a dental team or learning group. A publication's findings need to be considered alongside current clinical guidance, the person's condition and their preferences. This article does not select treatment or a product for an individual.

Sources: Delivering better oral health: prevention

Read beyond the headline

Record four things from the methods and results before writing a conclusion:

• Participants. Age, starting condition, setting and important exclusions. Findings in healthy volunteers may not apply to someone with complex needs.
• Comparison. Brushing alone, another technique, placebo or usual care? Did groups receive different instruction or support?
• Measured outcome. Plaque, bleeding, new carious lesions, tooth loss or quality of life? A change in one measure does not establish changes in the others.
• Follow-up and certainty. How long did the study last, how many participants dropped out and how precise is the estimate? A small difference with substantial uncertainty needs careful explanation.

Check funding and declared interests. These inform appraisal without establishing whether a result is true. In a systematic review, also check the last search date: publication year is not necessarily the year of the newest included evidence.

Example: fluoride toothpaste and decay

Cochrane's 2019 review supports fluoride toothpaste over non-fluoride toothpaste for caries prevention. Certainty varies across concentration comparisons; choosing for young children also requires consideration of fluorosis. The search ended in August 2018.

For discussion, open the actual comparison. Check whether it concerns primary or permanent teeth and how decay was measured. Do not turn the overall finding into one concentration for every age. Compare it with current age-specific recommendations and individual assessment.

Sources: Fluoride toothpastes: systematic review, 2019 · Delivering better oral health: prevention

Example: interdental cleaning and gums

Cochrane (2019) found possible benefits of added floss or interdental brushes for some plaque and gingivitis measures. Evidence was low to very low certainty, mostly short-term; included studies did not assess caries. Searches ended in January 2019.

Ask a learning group: “What would we change in a claim that every interdental tool prevents tooth loss?” Identify what was actually measured and what remains unknown. Individual advice also needs assessment of spaces, gum health and safe use.

Our oral-care product guides can support preparation of an explanation. These two dated reviews are learning examples, not a comprehensive review of the literature through 2026.

Sources: Interdental cleaning: systematic review, 2019

Give numbers their context

When reliable evidence fits the question, present absolute numbers, a consistent denominator and a time period. NICE recommends this approach to risk communication. Relative change should not become a promise for one patient.

A fictional exercise: an outcome occurs in 20 of 100 people over one year, compared with 15 of 100. The difference is 5 people per 100, or 5 percentage points. The relative reduction is 25%. These describe the same invented numbers, not a dental study's findings. For actual research, add uncertainty and explain applicability.

Fictional example

Over 1 year · 1 dot = 1 person

20 / 100

15 / 100

• With the outcome
• Without the outcome

Absolute difference

5 / 100

5 percentage points

Relative reduction

25%

5 ÷ 20 = 25%

Sources: Shared decision making