Clinical Research Abstracts

Waterpik® Water Flosser: Unequivocally Proven Safe in Clinical Studies Over 5 Decades

Safety of a Water Flosser: A Literature Review

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Since the introduction of the first Waterpik® Water Flosser in 1962, over 60 clinical trials have been published. Collectively, the studies demonstrate significant plaque removal, reduction of gingival bleeding, and reversal of inflammation (gingivitis). The majority of the studies are randomized controlled trials and published in peer-reviewed journals providing the reader with the best evidence to make informed clinical decisions. Interestingly, there are some who still have questions about the safety of the device. This literature review was designed specifically to address the safety of a Water Flosser. Interestingly, most of the available evidence was conducted on the Waterpik® Water Flosser.


This review was divided into four sections: histological findings, subgingival pathogens, probing pocket depth and clinical attachment levels, and bacteremia. These categories were chosen to address specific questions and misunderstandings centred on the safety of the Water Flosser or personal anecdotal beliefs that are not based on scientific evidence.


  • Histological findings: Studies showed a significant reduction in inflammation on the cellular level compared to non-treated sites which showed varying levels of inflammation. This refutes the belief that a Water Flosser can damage the periodontal pocket tissue.
  • Subgingival pathogens: Studies show significant removal of subgingival pathogens, even in deep pockets, with the use of a Water Flosser. This was not generally seen in non-Water Flossed sites. This refutes the belief that bacteria are driven deeper into pockets.
  • Pocket depths and clinical attachment levels: Studies show either no change in probing pocket depth and clinical attachment levels or a significant improvement. These studies directly address the concern that a Water Flosser can break the epithelial attachment when, in fact, there is an improvement in inflammation and no change in the attachment.
  • Bacteremia: The incidence of bacteremia is the same for tooth brushing, flossing, wooden toothpicks and sticks, water flossing and mastication. This is a great example of how assumptions have no basis in healthcare, just because a water flosser provides pulsating water that hits the tooth does not mean it will increase the incidence of bacteremia.


The Waterpik® Water Flosser has been proven safe.

Findings from Clinical Studies on the Safety of the Waterpik® Water Flosser

  • Histological reduction in inflammation
  • Reduction or stability of probing pocket depth
  • Improvement or stability of clinical attachment levels
  • Removal of subgingival pathogenic bacteria
  • Improvements in morphological subgingival flora
  • No adverse effects reported
  • Clinical changes demonstrating a reduction in gingivitis, inflammation, and plaque