Oral healthcare providers know that toothbrushing alone does not effectively remove interproximal plaque biofilm from teeth.1 The challenge is getting patients to use something in between their teeth, to do something in addition to brushing. Usually, that something is the use of dental floss. Likewise, for patients the consistent daily challenge is using dental floss. For most, this challenge is finding the motivation to floss habitually. For many others, the problem is the dexterity required.2 For those who do floss routinely, less than half may be using proper flossing technique.3 If flossing is so challenging and frustrating for practitioners and patients alike, why is there still so much focus on recommending it?
What a relief it would be to many dental patients if floss would just go away. For two thirds of them, it already has.4 They do not think about it, they do not use it, and they do not care that they do not use it except possibly during the regular scolding that they hear at their dental visits.
The routine use of dental floss has consistently been dramatically low.2 Even among a group of health professionals, including dentists, less than two thirds used floss daily.5 The reality is that flossing is a demanding means of interproximal cleaning. The effectiveness of a product or device is irrelevant, if noncompliance issues are compelling, as with flossing.
Not surprisingly, oral healthcare providers care a great deal more about flossing than their patients. Patients expect the dental floss lecture at each visit, but many do not really listen to it. More importantly, often they hate dental floss and do not plan to change their behaviors. The floss talk may no longer instill feelings of guilt, which practitioners mistakenly hope will lead to behavior changes. It was Albert Einstein who defined insanity as doing the same thing over and over, expecting different results. It turns out that he described quite well the continued efforts of dental professionals to get their patients to use dental floss regularly.
Dr. Harriet Lerner has written several books for the mainstream reader about facilitating changes in relationships. Most of these books have the word dance in them, such as the The Dance of Anger, The Dance of Intimacy, and The Dance of Fear.6-8 The word dance in the titles suggests that for change to occur, one party must change the dance step. When that happens, the other party, surprised at the change, has no choice but to vary his or her dance step in response. This process is how change occurs. When the dance steps always stay the same, so does the dance. When the decision is made to no longer lecture patients about their need to floss, practitioners will have changed the dance step, and consequently, so will patients. Perhaps it is time to publish The Dance of Floss.
Adjunctive oral care would be easier to attain if there were an acceptable alternative to floss that enhanced patient compliance by offering yet another way to complete interproximal cleaning. It would not necessarily replace dental floss, although for some patients—especially patients who are adverse to flossing—it may. This something would have to be easier to use and comply with, as well as be easily added to a daily routine. The alternative would need to prevent and control gingivitis and periodontitis. Some newly developed device that is here today and gone tomorrow would not be an option. It would need to stay on the market reliably, and be easy for patients to find and buy.
There are devices that non-flossers can more readily accept. And practitioners have always had the power to recommend something besides floss. Remember The Wizard of Oz, when the good witch Glinda tells Dorothy that she has always had the power to get home, she just needed to want it badly enough? Most practitioners do want to recommend something besides floss badly enough, especially those who are frustrated by unsuccessfully pushing floss for so long.
One interdental device that could be used in place of floss has existed for more than 45 years. If this device has been around for decades, why haven't dental professionals fully embraced it? The answer is that current science has finally caught up with the technology. In an amazing twist of historical perspective, daily oral irrigation has reemerged as a powerfully effective technology. The dental water jet device was introduced back when we used to think plaque biofilm was just plaque (Figure 1). Early daily oral irrigation studies showed that the amount of disclosed plaque did not always change dramatically, yet improvement could be demonstrated in gingival parameters. Anything that did not remove “plaque” significantly, as measured by disclosing, was not judged to be very worthwhile. It was difficult to make sense of the improved gingival findings, and practitioners did not want to advocate a practice that did not remove a significant amount of plaque. Consequently, the Waterpik® dental water jet (Water Pik, Inc, Fort Collins, CO) was not often recommended. The current understanding of plaque as a biofilm has changed everything. The dental profession now knows that it is not only the amount of plaque biofilm present, but also its content, that impacts virulence. So, even if the total amount of plaque biofilm is not altered, a change in the content of the biofilm, rendering it less toxic to periodontal tissues, can decrease the disease-causing potential.
Armed with this new understanding of plaque biofilm and the role of inflammation in periodontal disease, the dental water jet (Figure 2 and Figure 3) is now making a comeback, like an actor being rediscovered due to a new starring role.
Many studies have demonstrated that regular use of the dental water jet reduces the important parameters of gingival/periodontal disease: periodontal pathogens, bleeding, probing depth, calculus, and gingivitis.9-11 The fascinating part is how it happens. Not only are the destructive pathogens affected, but so are the host inflammatory agents.12 There is finally an explanation for how the reduction in the amount of plaque biofilm after using a Waterpik dental water jet can be equivalent to traditional self-care, and yet lead to greater improvement in the disease process. Dental floss works by disrupting plaque biofilm, but there is no evidence to support its effect on inflammatory agents.
Today, the spotlight is on the importance of inflammation in periodontal disease and in the linkages between systemic and oral disease. A new oral disease paradigm requires a new look at the evidence regarding the benefits of oral irrigation.
Daily oral irrigation has a direct impact on the inflammatory process. In a study of the gingival crevicular fluid of adult periodontal patients, 2 weeks of oral irrigation added to routine oral hygiene was shown to impact inflammatory mediators.12 Two mediators that promote inflammation were reduced, one anti-inflammatory mediator was increased, and the level of a different anti-inflammatory mediator was maintained. Additionally, there was a significant reduction in bleeding on probing, which correlated with the reduction in the inflammation-promoting agents.
Similarly, another investigation demonstrated that oral irrigation can change a constituent of plaque biofilm. Ordinarily, a fibrin-like mesh envelops biofilm and its associated debris. This mesh envelope is not evident after oral irrigation,9 offering more evidence to support the idea that changes in biofilm components can contribute to improvement in clinical parameters.
But, would the use of floss have had the same outcome? That question has been answered by a dental hygienist researcher, Dr. Caren Barnes, of the University of Nebraska.10 She and her colleagues acquired a population of about 100 people with moderate plaque and bleeding. One third of the patients added daily oral irrigation to their use of a power toothbrush, one third added oral irrigation to their use of a manual toothbrush, and another third combined manual brushing and flossing. The researchers were able to demonstrate that a manual toothbrush and oral irrigation significantly reduced bleeding and gingivitis over manual brushing and flossing. And, the use of a power toothbrush and oral irrigation was significantly better than a manual toothbrush and flossing in reducing bleeding and gingivitis.10 Finally, there is an evidence-based alternative to the pairing of brushing and flossing, with the attendant compliance issues.
Despite the proven benefits of power toothbrushing, a large category of patients will not use a power toothbrush, and also will not floss. The Barnes study suggests that the addition of an oral irrigator could overcome the deficiencies of manual brushing as compared with power brushing. Patients would be relieved and thrilled if the lecture designed to coax them into regular flossing would stop. Will they prefer a dental water jet to floss? Many practitioners find that patients prefer any alternative to floss.
The American Academy of Periodontology, often viewed as the authority in treatment recommendations, has endorsed oral irrigation by promoting supragingival lavage to assist those with gingivitis or poor oral hygiene.13 It is suggested that the greatest benefit of oral irrigation would be for patients who perform inadequate interproximal cleansing.13 Inadequate interproximal cleansing is commonplace. Consequently, it appears that most patients could benefit from home use of oral irrigation.
Interestingly, there has been evidence in the literature for quite some time that various other alternate approaches are equivalent or superior to floss for oral self-care. These include rinses of chlorhexidine and fluoride as well as cetylpyridinium chloride and fluoride, which can reduce interproximal plaque better than floss;14 interdental brushes, which can improve interproximal gingivitis better than floss;15 and curved interdental brushes, which can improve clinical parameters better than floss after 6 and 12 weeks.16 Another study showed that plaque biofilm removal and probing depth reduction was superior to that achieved with floss after 6 weeks of interdental brush use; patients also preferred the brushes over floss.17 One possible reason that floss does not perform as well in plaque biofilm removal in some studies is its inability to conform to a concave interproximal surface. An equivalent benefit has been demonstrated between the interdental brush and floss on subgingival plaque biofilm and proximal gingival health, and again, patients preferred the interdental brush because of simplicity of use.18
Clearly, practitioners have witnessed that for periodontal health, other options such as the Waterpik dental water jet, chemotherapeutic rinses, and interdental brushes meet or beat floss. Oral irrigation is the only one of these options that also impacts the mediators of inflammation, which are important in controlling periodontal disease. Research results, combined with descriptions in the literature of self-induced damage that can result from improper floss use,19,20 further support the idea that floss may not be the panacea that it has been considered to be for so long.
Perhaps there are suitable alternatives to floss for soft-tissue health, but for decay prevention, floss has traditionally been viewed as essential, particularly for those prone to interproximal decay. Despite almost universal endorsement in dentistry, it is surprising how little evidence is available to support this claim. A comprehensive, systematic review of the literature on dental flossing and interproximal caries was published recently.21 Six trials were identified; however, study-to-study differences and the potential for bias among some of the researchers complicated study comparisons. No research studies were identified that used adult patients or unsupervised self-flossing.
Among the reviewed studies, flossing was performed professionally in four of the trials, supervised in one trial, and unsupervised in another. Four studies did not show a flossing benefit for caries prevention. For three of these studies, reasons such as small sample size and infrequent professional flossing may have precluded a flossing benefit. The fourth study used a split-mouth design with young adolescents who were supervised as they self-flossed each school day for 2 years. An anti-caries benefit could not be demonstrated. One explanation might be that the study protocol included pulling waxed floss up and down once through the contact point instead of wrapping the floss around the tooth and using up-and-down strokes. Another reason that an anti-caries benefit was not evident may have been that the use of fluoridated toothpaste by the children masked the benefits of flossing. In the two studies where a flossing benefit was observed, exposure to topical fluorides was unclear.
Consequently, the authors of the systematic review suggested that the presence of topical fluoride exposure, which is so prevalent today, may mask the sole effects of flossing. The authors observed that in the absence of convincing decay-preventive evidence, the endorsement of floss for caries prevention has been based largely on common sense logic. This logic suggests that plaque biofilm is cariogenic and because dental floss disrupts and removes some interproximal plaque biofilm, it would follow that flossing would reduce the caries risk. The authors went on to state that this logic-based assessment is a low form of scientific evidence, particularly when there is stronger support for other caries- preventive measures. They also provided a reminder about the possible harmful effects of improper self-flossing and advocated for more research about floss damage.19,20
Certainly, if flossing is already a habit, the practice should be continued, provided that it is improving oral health. The configuration of the gingival unit filling the embrasure space can determine indication for flossing. Floss is most effective in removing plaque in type I embrasures where the papilla fills the interproximal space. For type II, with slight to moderate recession of the papilla, or type III, with extensive loss of papilla, other oral hygiene practices can be more effective than the use of dental floss.22,23
The reciprocal relationship between oral and systemic health is particularly evident in diabetes. Patients with diabetes who used a dental water jet in addition to brushing and flossing showed reduced levels of several proinflammatory mediators and a reduction in periodontal and systemic measures.24 Currently, the oral irrigator appears to be about the only oral hygiene device where the impact on host immune factors has been documented and correlated with a beneficial effect on soft-tissue health. Other beneficial applications of oral irrigation have been demonstrated for implants25 and for orthodontic patients, where superiority over manual brushing and flossing has been demonstrated.26
The Canadian Dental Hygiene Association recently commissioned a review and critical analysis of the literature on dental flossing to develop a position statement on the use of dental flossing as a preventive oral health behavior. This comprehensive review focused on compliance issues, difficulty of changing behaviors toward flossing, differing levels of efficacy depending on oral conditions, and the variety of other less awkward forms of interproximal cleansing. After supporting the importance of interdental cleansing to supplement toothbrushing, the position statement asserted that interproximal cleansing recommendations should be based on the oral condition, preference, and ability of each individual.2
Among oral healthcare providers, recommending the combined floss and toothbrush regimen has been traditional. However, evidence-based practice has replaced tradition-based practice. To be truly patient-centered, practitioners must shift to recommendations that patients can embrace. New knowledge about plaque biofilm and the role of the immune system has been incorporated into current understanding of the etiology of oral disease. It is time to recommend an oral hygiene self-care regimen that is aligned with current concepts of human behavior and oral disease etiology. The Waterpik dental water jet is one such regimen.
The author has received an honorarium from Water Pik, Inc.
References
1. Carter-Hanson C, Gadbury-Amyot C, Killoy W. Comparison of the plaque removal efficacy of a new flossing aid (Quik Floss) to finger flossing. J Clin Periodontol. 1996;23(9):873-878.
2. Asadoorian J. Flossing: Canadian Dental Hygienists Association position statement. Canadian Journal of Dental Hygiene. 2006; 40(3):1-10.
3. Segelnick SL. A survey of floss frequency, habit and technique in a hospital dental clinic and private periodontal practice. N Y State Dent J. 2004;70(5): 28-33.
4. Lang WP, Ronis DL, Farghaly MM. Preventive behaviors as correlates of periodontal health status. J Public Health Dent. 1995;55(11): 10-17.
5. Merchant A, Pitiphat W, Douglass D, et al. Oral hygiene practices and periodontitis in health care professionals. J Periodontol. 2002;73(5):531-535.
6. Lerner HG. The Dance of Anger. New York, NY: Harper and Row Publishers Inc; 1985.
7. Lerner HG. The Dance of Intimacy. New York, NY: Harper and Row Publisher Inc; 1989.
8. Lerner HG. The Dance of Fear. New York, NY: HarperCollins Publisher, Inc; 2004.
9. Cobb CM, Rodgers RL, Killoy WJ. Ultrastructural examination of human periodontal pockets following the use of an oral irrigation device in vivo. J Periodontol. 1988;59(3):155-163.
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11. Flemmig TF, Epp B, Funkenhauser Z, et al. Adjunctive supragingival irrigation with acetylsalicylic acid in periodontal supportive therapy. J Clin Periodontol. 1995;22(6): 427-433.
12. Cutler CW, Stanford TW, Abraham C, et al. Clinical benefits of oral irrigation for periodontitis are related to reduction of pro-inflammatory cytokine levels and plaque. J Clin Periodontol. 2000;27(2):134-143.
13. Greenstein G, Research, Science and Therapy Committee of the American Academy of Periodontology. Position paper: the role of supra- and subgingival irrigation in the treatment of periodontal diseases. J Periodontol. 2005;76(11):2015-2027.
14. Zimmer S, Kolbe C, Kaiser G, et al. Clinical efficacy of flossing versus use of antimicrobial rinses. J Periodontol. 2006:77(8): 1380-1385.
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18. Noorlin I, Watts TL. A comparison of the efficacy and ease of use of dental floss and interproximal bushes in a randomised split mouth trial incorporating an assessment of subgingival plaque. Oral Health Prev Dent. 2007;5(1): 13-18.
19. Walters JD, Chang EI. Periodontal bone loss associated with an improper flossing technique: a case report. Int J Dent Hyg. 2003;1:115-119.
20. Hallmon WW, Waldrop TC, Houston GD, et al. Flossing clefts. Clinical and histologic observations. J Periodontol. 1986;57(8): 501-504.
21. Hujoel PP, Cunha-Cruz J, Banting DW, et al. Dental flossing and interproximal caries: a systematic review. J Dent Res. 2006; 85(4):298-305.
22. Proceedings of the World Workshop in Clinical Periodontics Consensus Report. Chicago, IL: American Academy of Periodontology; 1989:discussion section II:11-33.
23. Carr MP, Rice GL, Horton E. Evaluation of floss types for interproximal plaque removal. Am J Dent. 2000;13(4):212-214.
24. Al-Mubarak S, Ciancio S, Aljada A, et al. Comparative evaluation of adjunctive oral irrigation in diabetics. J Clin Periodontol. 2002;29(4):295-300.
25. Felo A, Shibly O, Ciancio SG, et al. Effects of subgingival chlorhexidine irrigation on peri-implant maintenance. Am J Dent. 1997;10(2):107-110.
26. Sharma NC, Lyle DM, Qaqish JG, et al. The effect of a dental water jet with orthodontic tip on plaque and bleeding in adolescent patients with fixed orthodontic appliances. Am J Orthodont Dentofacial Orthop. 2008;133(4): 565-571.
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