Interdental cleaning is an important part of a complete oral hygiene routine, reaching areas where a toothbrush cannot effectively clean. Traditional string flossing is a mechanical method, while water flossing utilizes a hydro-pulsating stream to clear debris and disrupt plaque biofilm. Determining which method is better is complex, as each offers distinct advantages based on clinical evidence and individual needs. The optimal choice depends on the specific dental health metrics being measured and the personal circumstances of the user.
How String Floss and Water Floss Work
String floss operates through a mechanical scraping action designed to physically remove plaque from the interproximal surfaces of teeth. To be fully effective, the user must wrap the floss into a “C” shape around each tooth and slide it gently below the gum line into the gingival sulcus. This manual contact removes the sticky biofilm that forms at the tightest contact points between teeth.
A water flosser, also known as an oral irrigator, employs a hydro-kinetic mechanism to clean the interdental spaces. The device ejects a stream of water in rapid, short bursts, typically operating at a pressure range of 50 to 90 psi. This pulsed water jet creates a compression and decompression phase that works to flush out food particles and loosely lodged plaque debris. The stream is directed at a 90-degree angle to the tooth surface, allowing the water to penetrate below the gum line and into areas string floss cannot easily access.
Clinical Evidence for Plaque Removal
Clinical research shows both string floss and water floss are effective tools, but they excel in different areas of oral health. String floss remains highly effective for the direct, physical removal of mature, sticky plaque biofilm at the point where teeth touch. Its scraping action provides mechanical removal of hard plaque colonies from the tooth surface itself.
However, the efficacy of water flossers often surpasses string floss when measuring overall gum health and inflammation reduction. Studies have found that adding a water flosser to a regular brushing routine is significantly more effective in reducing gingivitis and bleeding on probing (BOP) than combining brushing with string floss. One trial showed that a water flosser was up to 52% better at reducing gingivitis and 93% better at reducing bleeding than traditional floss after a four-week period.
For overall plaque reduction, a systematic review suggests that the majority of studies favor water flossers over dental floss, particularly in hard-to-reach interproximal areas. The pulsating water stream reaches irregular niches and subgingival regions that string floss often misses. This ability to flush out bacteria and debris leads to the superior reduction in inflammation observed in many trials. Many water flosser products have earned the American Dental Association (ADA) Seal of Acceptance, recognizing their safety and effectiveness.
Situations Where One Method Excels
The best choice often shifts from clinical data to practical application, where specific dental conditions favor one method over the other. Individuals with orthodontic appliances, such as braces, find the water flosser particularly helpful. The pressurized water stream easily cleans around brackets and wires, a task that requires tedious threading with string floss and often leads to low compliance. People with dental implants, bridges, or crowns also benefit, as the water flosser cleans around abutments and beneath restorations without the risk of snagging or damaging the dental work.
For users with limited dexterity, such as those with arthritis or other mobility issues, the water flosser requires minimal fine motor control and is easier to use. The device’s ease of use often leads to more consistent daily cleaning, which is a major factor in maintaining oral health.
In contrast, string floss remains the preferred method for physically scraping plaque off the tightest contact points between teeth, where mechanical friction is necessary. While the initial cost of a water flosser is significantly higher, the ongoing cost of string floss is negligible, making it the most economical choice. Ultimately, many dental professionals suggest that for the most comprehensive hygiene, combining the scraping action of string floss with the flushing action of a water flosser provides the most thorough cleaning.