The video introduces the experiment and the motivations behind it.

• The experiment aims to compare six best-selling toothbrushes to see which one is most effective at cleaning teeth.
• Questions about bristle effectiveness, flossing necessity, and the difference between cheap and expensive toothbrushes are raised.
• The video promises surprising results from the experiment.

Brushing habits of participants are discussed and the experiment guidelines are established.

• Participants include people with different brushing habits, from once a day to multiple times a day.
• The toothpaste is standardized and brushing time is set to two minutes for consistency.
• Disclosure tablets are used post-brushing to reveal plaque left on teeth.

Manual toothbrushes are tested and results are compared.

• Three manual toothbrushes, including a cheap generic, dentist-recommended, and a social media popularized brush, are tested.
• The cheap generic brush delivers surprisingly good results despite its price.
• The dentist-recommended brush shows mixed results, while the social media brush was too soft to be effective.

Electric toothbrush heads are tested and evaluated.

• Two electric toothbrush heads, cross-action and tri-zone, are tested with a basic Oral-B electric toothbrush base.
• The cross-action head requires a precise technique to avoid missing teeth while brushing.
• The tri-zone head has a unique side-to-side motion that delivers mixed results.

The Sonicare toothbrush is tested and overall conclusions are drawn from the experiment.

• The Sonicare vibrates at a much higher frequency than electric brushes but fails to achieve superior results.
• Participants find the Sonicare to be intense and not necessarily better than manual brushing.
• The experiment concludes that more expensive toothbrushes don't guarantee better cleaning and highlights the importance of technique and flossing.