K = chewing surfaces (Kauflächen)
The chewing surfaces are cleaned with horizontal back-and-forth movements of the brush.
A brushing technique for milk teeth following the KAI method.

Learning to brush
Even the first milk tooth should be cleaned carefully with a soft brush or a cotton bud and a small amount of toothpaste. Milk teeth should be cleaned twice a day or more with a special children's toothbrush with soft, multi-tufted, rounded bristles and a children's toothpaste containing about 500 ppm fluoride. Your dental practice will tell you everything important about the particular properties of fluorides. Fluoride strengthens the redeposition of minerals in the enamel and helps prevent caries, increasing the teeth's resistance to attack by the metabolic products of the bacteria in plaque.
Incorrect brushing can damage teeth and gums, so using a systematic cleaning method matters. Among the techniques recommended is the KAI method, which children learn easily and which promises a good cleaning result.
Three steps, always in the same order – that way no surface is forgotten.
The chewing surfaces are cleaned with horizontal back-and-forth movements of the brush.
The outer surfaces of the teeth are cleaned with small circular movements of the brush.
The inner surfaces are brushed from the gum towards the tooth with small circular movements. The brush is guided from the gum towards the tooth – from red to white.
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