Periodontal Nitwits and Flossing

Dec. 1, 2007
I occasionally enjoy reading about dinosaurs and was a big fan of Jurassic Park.

by Lynne H. Slim, RDH, BSDH, MSDH

I occasionally enjoy reading about dinosaurs and was a big fan of Jurassic Park. One fact that I remember is that dinosaurs liked to live in many different habitats, from open plains to forests to the edges of swamps, lakes, and oceans. Some dinosaurs were as tall as trees and some were as small as a chicken. Just like modern humans, there were many different varieties.

Subgingival habitats in human dentitions vary, too. Periodontal researchers have discovered that the subgingival microbiota (gumbugs in a given environment) is different in periodontally healthy subjects compared to subjects with periodontitis.1 Not only do subjects with periodontitis have higher counts of bacterial species in the red and orange complexes, these homo sapiens typically have embrasures that can sometimes accommodate a Mack truck in addition to dental floss.

Let me back up a second and tell you about one of my biggest frustrations with my fellow oral health-care professionals. I like to work as a temp. (Am I a sucker for punishment, or do I like the money?) I especially like to meet new staff members in unique environments. It never ceases to amaze me that some clinicians are practicing and educating patients the way we used to 20 years ago!

I recently temped at a dental practice where the dentist challenged me about the use of interdental brushes around posterior teeth. He actually told me that interdental brushes did not remove oral biofilms. Apparently, I had told a patient that it was OK to use a thin interdental brush in posterior embrasures and it was also OK not to floss those particular interdental spaces if he was using an interdental brush.

The patient questioned the dentist about my recommendation and the dentist treated me as if I had committed an act of heresy. I felt as if I was on trial as a witch who had committed some outrageous act. To make matters worse, I returned to my permanent dental practice home (where I work one day a week), and the hygienists there also challenged me on my decision-making about eliminating flossing in posterior quadrants for periodontal patients.

In fact, probably all of the hygienists and dentists who work in our building (and there are many, including a periodontist and his team) would like to have me tarred and feathered for my outrageous stance. Most of them believe that thin, unwaxed dental floss is superior to other types of floss. Not only was I slapped down once, but twice!

Unfortunately, this scenario is probably played out frequently all over the United States and abroad, which reveals the huge disconnection between clinicians who are evidence-based (or what I’ll now call periodontal nerds) and those who are periodontal nitwits. Don’t ask me what the name “nitwits” means because I don’t want to insult anyone. But a quick Google will offer a definition, and you can find a suitable synonym for the expression.

According to, nerds possess above average intelligence and they are aware of their status and don’t mind what people think of them. They’re smart and not wrapped up in superficial worries.

Those of us who spend most of our clinical hours debriding periodontal pockets know, without a shadow of a doubt, that thin, unwaxed dental floss “ain’t gonna” adequately remove oral biofilms in interdental areas around posterior teeth. It’s simply a matter of anatomy and having a vision of the interdental area. I tell patients this (and I have a nice image of the two adjoining teeth to better illustrate my point):

Imagine, if you will, two hourglasses side by side as close as possible. Now imagine a string passed between the opening between these two. Where the hourglasses come into contact, the string will touch both of them but at the waist of the hourglasses the string could miss all surfaces completely.

When I am challenged by a colleague about something that pertains to dental hygiene, I typically back off and do my homework before I respond. In this particular case, I was challenged by both a dentist and two hygienists, and I needed to make sure that I could respond convincingly in a professional manner.

As the body of dental literature continues to expand, it’s not always easy to search databases and get your hands on the appropriate research articles or systematic (high quality) reviews of the literature on a given topic. Most clinicians I know get their information from CE courses, from discussions with colleagues, or from reading magazines or journals. It’s also true that a clinician’s knowledge on a given subject is not always consistent with current scientific findings.2

In this instance, I began by e-mailing Trisha O’Hehir. When Trisha was editor of Perio Reports, she told me how she organized research by topic. So I knew that she must have a file on dental flossing research. Sure enough, Trisha provided several research articles for me to review.

I am not as organized as Trisha, but occasionally I surprise myself by keeping a document that comes in handy later. I happened to save the Canadian Dental Hygienists’ Association (CDHA) position paper on flossing! The CDHA position paper is one of the best I’ve ever read. It’s not only a comprehensive review of the literature from 1995-2005, but it also provides a critical analysis of the literature and a position statement on the use of dental floss.3

OK, I won’t keep you in suspense. Here’s what I found. Although I had already read this information at one time or another, I could now talk like the periodontal nerd that I am.

I’m going to use some strong language here so those who are extremely sensitive and easily offended, get over it! It’s time for the periodontal nitwits among us to absorb this information once and for all:

• According to CDHA, the literature available before 2000 does not show that one specific type of floss is superior to any other. In one particular study, four types of floss were compared: woven, waxed, unwaxed and shred-resistant. The study measured total, anterior and posterior interdental plaque scores, and there were no significant differences for the floss types among the selected sites. It was also reported that unwaxed floss received the most negative feedback from the study subjects.3

• Studies conducted from 1995-2005 that compared the use of manual flossing to floss holder devices have shown that clinical outcome measures (i.e. biofilm removal, bleeding and gingival response) were similar with no significant improvements. In other words, floss-holding devices are as effective as manual flossing. In one study, approximately 40 percent of the study subjects did not use a proper finger flossing technique and it has also been discovered that floss-holding devices are preferred to finger flossing.3

• Flossing has been shown to be less effective when there is interproximal recession and subsequent widening of interdental embrasures. Some studies that have compared flossing to other interproximal cleaning aids have been equivocal; however, more recent studies have shown at least comparable efficacy from interproximal cleaning devices like interdental brushes.3 In addition, where embrasures are wide, biofilm removal is more efficient with interdental brushes.3

If any of your patients ask you what percentage of the adult population flosses on a daily basis, the correct answer is a range from 10 percent to as high as 30 percent.3 Keep in mind that there are many factors that influence flossing behavior, and that the literature has repeatedly suggested that less-demanding means of cleaning interproximally are desired by patients and clinicians alike.

CDHA concluded its review by hinting that clinicians need to be aware of possible personal biases towards flossing, especially finger flossing. Instead, the author recommends interproximal cleaning recommendations based on each patient’s oral condition, preference and ability.

The choices for interdental biofilm removal are endless: floss holders, automated flossers, interdental brushes, picks, wooden and plastic toothpicks, and home irrigators. Like dinosaurs, a human’s periodontium varies and embrasures between posterior teeth vary widely. As periodontal disease most commonly affects the posterior interproximal sites, it’s critical to concentrate homecare efforts in these areas. So periodontal nitwits beware: join the periodontal nerds or be forever branded as a nitwit. ... I’m kidding, of course, but I hope you get the point!

About the Author

Lynne H. Slim, RDH, BSDH, MSDH, is a practicing hygienist/periodontal therapist who has more than 20 years’ experience in both clinical and educational settings. She is also president of Perio C Dent Inc. (Perio-Centered Dentistry), a practice-management consulting firm that specializes in creating outstanding dental hygiene teams. Lynne is a member of the Speaking and Consulting Network (SCN) that was founded by Linda Miles, and has won two first-place journalism awards from ADHA. Lynne is also owner/moderator of a periodontal therapist yahoo group: She can be contacted at [email protected].


1 Socransky S and Haffajee AD. Periodontal microbial etiology. Periodontology 2000; 2005: 38: 135-187.

2 Cobban SJ. Evidence-based practice and professionalization of dental hygiene. Int J Dent Hygiene 2004: 2: 152-160.

3 Asadoorian J. CDHA position paper. Canadian J of Dent Hygiene 2006: 40(9): 1-10.