Interdental cleaning is a necessary practice for maintaining a healthy mouth, as a toothbrush alone cannot effectively reach the tight spaces between teeth and beneath the gumline. For decades, traditional string floss has been the standard method for this task, but a modern alternative, the water flosser, has grown in popularity. A water flosser, also known as an oral irrigator, is a device that utilizes a motor and pump to deliver a stream of pressurized, pulsating water. This technology aims to dislodge food particles and disrupt the sticky bacterial film known as plaque from areas a toothbrush misses.
How Water Jets Compare to String Floss
The difference between these two interdental aids lies entirely in their mechanical action. Traditional string floss requires manual dexterity to scrape plaque from the surfaces of the teeth. A user must wrap the floss around the tooth in a “C” shape and slide it gently up and down to remove debris and disrupt the attached biofilm. This contact-based method is highly effective for cleaning the tightest spots where two teeth touch.
In contrast, a water flosser operates on a principle of hydrokinetic energy. The device ejects a stream of water that pulses, typically between 1,200 and 1,600 times per minute, at pressures up to 90 pounds per square inch (psi). This pulsating action generates a cleansing wave that flushes out loose debris and penetrates below the gumline to a depth string floss cannot easily reach. The water jet removes plaque biofilm through irrigation rather than by direct physical contact or scraping.
The primary advantage of the water flosser’s mechanism is its ability to access areas that are difficult to navigate with string floss. The gentle, flushing action is particularly effective at rinsing the gumline and the proximal surfaces of the teeth. String floss, however, maintains an edge in its ability to mechanically shear off the most stubbornly adhered plaque from the narrow contact points between teeth.
Scientific Evidence on Plaque and Gum Health
Clinical studies comparing the two methods focus on measurable outcomes such as plaque index reduction and gingival health indicators like the bleeding index. Regarding the removal of plaque from between teeth, research results are comparable, with some studies showing that string floss and water flossers remove a similar percentage of interdental plaque, often in the range of 85% to 89%. However, when a water flosser is used in conjunction with a manual toothbrush, some studies report up to a 29% better plaque reduction compared to a manual toothbrush combined with string floss.
The most significant clinical advantage for the water flosser appears in the reduction of gingivitis and gum bleeding. Several trials have demonstrated that oral irrigation is more effective at improving gum health than string flossing. For instance, in one four-week trial, participants who used a water flosser alongside brushing saw a 41 percentage point greater reduction in bleeding compared to those who used string floss with brushing.
This superior outcome in gum health is attributed to the water flosser’s ability to flush bacteria and inflammatory by-products from the sulcus, the shallow groove between the tooth and the gum. The pulsating water stream not only cleans but also provides a massaging effect to promote gum tissue health. While string floss is highly efficient at removing plaque at the direct contact point, the water flosser excels at flushing and disrupting the bacterial film in the larger, surrounding areas and beneath the gumline.
When Water Flossers Are Recommended
Water flossers represent a significant practical benefit for individuals with specific dental hardware or physical limitations. Patients with orthodontic braces, for example, find that the pressurized jet easily cleans around brackets and wires, a task that requires considerable time with string floss. Similarly, those with complex dental work such as bridges, crowns, or dental implants can use the water stream to clean underneath and around these structures without the risk of snagging or disrupting the restorations.
The water flosser is also frequently recommended for people who have limited hand mobility, such as those with arthritis, who struggle to manipulate a small piece of string. Furthermore, individuals with deep periodontal pockets—spaces greater than three millimeters between the gum and tooth—benefit greatly. Special tips are available to deliver water or therapeutic rinses deep into these pockets, areas that string floss cannot penetrate effectively.
Despite these advantages, water flossers have practical limitations. They are typically more expensive than string floss, with the initial cost of a countertop model often exceeding one hundred dollars. Countertop models also require dedicated space and an electrical outlet, which can be inconvenient in small bathrooms or for travel, though smaller cordless models do exist. While the learning curve is minimal, some users may initially find the device messy until they master the technique of keeping their lips slightly closed around the tip.
Incorporating Flossing into Your Daily Routine
To maximize the benefits of either method, consistency is the most important factor. Dental professionals generally advise cleaning between the teeth once per day. For most people, it is optimal to perform the interdental cleaning step before brushing. This sequence dislodges any trapped food particles and plaque, allowing the fluoride in the toothpaste to reach the newly cleaned surfaces more effectively during the subsequent brushing step.
For those who use string floss, proper technique involves using a fresh section of floss for each tooth and creating that C-shape curve to scrub both the front and back side of each tooth. With a water flosser, the tip should be held at a 90-degree angle to the tooth surface and aimed directly at the gumline. Systematically move along the gumline, pausing briefly between each tooth.
The recommended duration for a thorough water flossing session is between one to two minutes, with many devices holding enough water for at least 90 seconds. To ensure full coverage, a good pace involves spending approximately two to three seconds on the front and back of each tooth. Consistency and proper technique are necessary to achieve a high level of oral hygiene.