Spending just five more seconds on a single spot removes dental plaque far more effectively than changing brushing technique, according to a new study.
A research team led by Professor Cho Hyun-jae of Seoul National University's School of Dentistry conducted the study on 88 adults who brushed their teeth as they normally would, and analyzed video footage from 78 of them whose data was valid. The way participants brushed was broken down using behavior analysis software, converting the time spent on each area, brush movements, and even the surface area touched by the bristles into numerical values. Researchers also factored in how worn the bristles were and how much toothpaste was used. After brushing, the plaque remaining on the teeth was scored using a specialized index, and a statistical model was used to determine which factors lowered the score.
The variable that showed the clearest difference was "brushing time per area." Teeth brushed for five seconds or more on a single spot had statistically significantly lower plaque indices than teeth brushed for less than five seconds. Even in a model that incorporated multiple variables at once, only brushing time and the area brushed remained significant. In contrast, specific brushing methods, the degree of bristle wear, and the amount of toothpaste used were found to have no clear effect on plaque removal.
Dental plaque is a thin film of food debris and bacteria. If not brushed away in time, bacteria burrow into the gums and cause inflammation at the tooth roots. The research team advised people to develop the habit of brushing every tooth surface evenly, spending at least five seconds on each spot. "Rather than what special technique you use to brush, the act of evenly distributing time across all tooth surfaces is more important," the team said. In 2019, the same team published an analysis finding that brushing side to side removes plaque better than the roll method, which moves only up and down. The latest study was recently published in the International Journal of Dental Hygiene.
