Update on oral irrigation

July 1, 2001
The fact that oral irrigation with water is more effective in reducing inflammation and bleeding than rinsing with chlorhexidine is a major finding.

The fact that oral irrigation with water is more effective in reducing inflammation and bleeding than rinsing with chlorhexidine is a major finding.

If you are not recommending oral irrigation to patients, or using it yourself, it's time to start. Oral irrigation was occasionally suggested as an alternative for those who didn't floss, but now it should be considered a regular part of oral hygiene for everyone.

The Water Pik® was first introduced in 1966 as a device for removing plaque and other debris. At that time, researchers were unable to show capabilities for removing plaque. Since then, it has taken a back seat to brushing and flossing, and has not really been accepted as a valuable part of plaque control.

The recent resurgence of research on oral irrigation has focused on plaque alteration rather than removal. Alterations of subgingival plaque have been measured both qualitatively and quantitatively as deep as 6 mm. Changes in the immune response are also evident, suggesting a mode of action other than plaque removal.

When plaque is measured using disclosing solution, oral irrigation does not demonstrate a measurable reduction. Despite this lack of plaque removal, home oral irrigation is effective in controlling gingival inflammation, with reductions in gingivitis scores, bleeding scores, pocket depths, and pro-inflammatory substances. With-out removing plaque, oral irrigation seems to affect bacteria within the plaque, the thickness of the plaque, and the immune response.

In a recent study that measured changes in 4 to 7 mm interproximal areas that were bleeding, reductions were observed in bleeding upon probing, pocket depths, and inflammatory cytokines, interleuken 1 (IL-1), and prostaglandin (PG-E2). The changes were noted after just 14 days of using the Water Pik, in addition to regular oral hygiene.

Chlorhexidine rinse is the most effective antiplaque agent now available. Rinsing, however, does not reach subgingival or interproximal areas. In fact, it only goes about 1 mm below the margin on the surfaces it does reach. In more than one study, oral irrigation with water was more effective in controlling gingivitis than rinsing with chlorhexidine. Adding chlorhexidine to the Water Pik improved results slightly more than water, but it isn't necessary to achieve better oral health. Water should be the first choice, saving chlorhexidine for patients with unresponsive areas. A three-month test in maintenance patients showed no difference between daily irrigation with water and daily irrigation with chlorhexidine.

Daily oral irrigation with water is more effective in controlling gingivitis than rinsing with chlorhexidine. Water irrigation shows no difference in the amount of plaque stained by disclosing solutions. The toxicity and thickness of the plaque, however, is altered by the irrigation, conditions that are not detected by disclosing solutions.

Despite the work of hygienists to educate and instruct the public about the importance of effective plaque control, only 30 percent of patients perform adequate home care with brushes and some sort of interproximal aid. Brushes reach less than 1 mm below the gingival margin. Interproximal plaque control is essential to periodontal health, but only 35 percent of patients occasionally use dental floss, and only 2 to 15 percent floss daily. For these reasons, oral irrigation provides an alternative for control of gingival inflammation.

Years ago, it was thought that oral irrigation forced bacteria and toxins into the tissues, but that concern was never substantiated by research. A few isolated case reports created a generalized scare. In contrast, the safety of irrigation is shown repeatedly in studies measuring bacteriemia potential. Systemically healthy patients are not subject to bacteriemia of any greater degree than that measured following dental procedures, brushing, flossing, or chewing. Patients requiring antibiotic premedication, however, should be periodontally healthy before using home irrigation or any other interdental tools.

Penetration of irrigation fluids is another area of controversy. When dyes and disclosing solutions are used to measure depth of penetration, the teeth must be extracted to do the measurements. Depending on the study, various levels of dye penetration are reported, ranging from 50 to 100 percent of the depth of the pocket. Jet irrigation will reach 3 mm or half the depth of the pocket. The Pik Pocket tip on a jet irrigator will allow penetration to 80 percent of the probing depth, or 7 to 8 mm. Cannula tips on jet irrigators are only slightly more effective than the Pik Pocket. In-office use of syringes shows dye reaching the base of the pocket.

Pocket architecture may explain the differences reported in studies measuring depth of penetration. Results must also be considered in light of the fact that measurements are made on the extracted teeth. Measurements are made from the gingival margin to the connective tissue attachment, rather than to the epithelial attachment. Scores are then at least 1 mm more than the actual pocket depth. Results, therefore, underestimate actual penetration of the irrigation fluid.

The two most popular tips are the jet tip and the Pik Pocket by Water Pik. The traditional jet irrigator tip was designed for supragingival irrigation that places the tip close, yet not really touching the tooth surface. The tip is not directed subgingivally, but aimed at a 90-degree angle to the tooth surface. The pressure of the water will take it subgingivally.

Pik Pocket subgingival tips are designed to deliver water and antimicrobials directly into the pockets. The soft rubber tip has a small opening, allowing a controlled amount of fluid to penetrate the pocket. The soft tip is also comfortable to direct into the subgingival and interproximal areas. In pockets less than 6 mm, the Pik Pocket tip is more effective than both the standard jet tip and the cannula tip. In deeper areas, the cannula tip may be more effective.

Some oral irrigators contain a magnetic component to change polarity of the water, resulting in reduced calculus accumulations on the lingual surfaces of the lower anterior teeth. Other irrigators are controlled by hand pumping rather than electricity, and two irrigators are attached between the showerhead and the water pipe, allowing for oral irrigation while showering. An idea for the future is a full-mouth irrigation device to ensure reaching all areas effectively and saving time.

The only irrigation device to receive ADA approval for reducing gingivitis and associated bacteria is the Water Pik. It's time we consider oral irrigation as a viable alternative to flossing. The fact that oral irrigation with water is more effective in reducing inflammation and bleeding than rinsing with chlorhexidine is a major finding. Oral irrigation should be part of our daily routine as well as that of our patients.

Trisha E. O'Hehir, RDH, BS, is a senior consulting editor of RDH. She also is editor of Perio Reports, a newsletter for dental professionals that addresses periodontics. The Web site for Perio Reports is www.perioreports.com. She can be reached by phone at (800) 374-4290 and by e-mail at [email protected].