January 2007
Volume 3, Issue 1

Assessment of Treatment Responses to Dental Flossing in Twins

Biesbrock A, Corby PM, Bartizek R, et al. J Periodontol. 2006;77(8):1386-1391.


BACKGROUND: The purpose of this study was to assess treatment responses to dental flossing in twins. METHODS: The study was a two-treatment, examiner-blind, randomized, parallel group, controlled study. Fifty-one twin pairs between 12 and 21 years of age were randomized to a 2-week supervised and unsupervised treatment regimen consisting of 1) tongue brushing and toothbrushing (TB) and 2) TB + flossing (TB+Fl). Clinical endpoints were gingival bleeding (papillary bleeding score [PBS]) and oral malodor (levels of volatile sulfur compounds [VSC]). Analysis of variance and covariance methodologies were employed to analyze the data. RESULTS: Baseline average PBS values were 1.352 and 1.342 for the TB+Fl and TB groups, respectively (P = 0.937). After 2 weeks of treatment, the TB+Fl group had a statistically significant decrease in PBS values of 0.558 (41.5% versus baseline), whereas the TB group showed no improvement from baseline. The change from baseline for the TB+Fl group was superior to that for the TB group (P < 0.001). Similar findings were observed for the number of baseline papillary bleeding sites. Baseline average intraoral halimeter values were 45.91 and 41.75 for the TB+Fl and TB groups, respectively (P = 0.504). Both treatment regimens demonstrated highly statistically significant reductions in intraoral breath values versus baseline (all P < 0.001), and the difference between treatment groups was not statistically significant (P = 0.339). Similar findings were found for expired air. CONCLUSIONS: In a well-matched twin cohort, tongue and toothbrushing plus flossing significantly decreased gingival bleeding after 2 weeks.


As dentists we accept some truths at face value as they are taught or described to us in continuing dental education lectures. One often-recommended treatment that has been evaluated in combination with other treatments but not by itself is the use of dental floss to control periodontal disease. If one does a search of the evidence-based database Cochrane Collaboration’s Central Register of Controlled Clinical Trials on the effects of dental flossing on gingival health, surprisingly, there are no systematic reviews that can be cited. It has been demonstrated that poor plaque control results in the ongoing process of increasing pathogenic bacteria that contribute to a gingival inflammatory response of the marginal gingival leading to a diagnosis of gingivitis. Also, bacterial plaque has been implicated in the presence of halitosis. The uniqueness of this study was the selection of 51 pairs of twins (31 monozygotic and 20 dizygotic; total N = 102) that were between the ages of 12 and 21. A baseline of gingival health was established using a papillary bleeding score (PBS)—which is an assessment of bleeding on interproximal papilla sites 15 seconds after stimulation with a toothpick—and measurements of volatile sulfur compounds using a halimeter. Data were collected 2 weeks after the initiation of the study. The authors of this study provide us with evidence that dental flossing has a significant benefit in controlling gingivitis and oral malodor when combined with tongue and tooth brushing. Also, there was a reduction in PBS values and papillary bleeding sites demonstrated with the additional use of supervised and unsupervised flossing for a 2-week period in a cohort with extensive gingival inflammation—eg, an average of 12 to 13 papillary sites, which corresponds to about half of all available sites for a particular individual. This study allows clinicians to recommend specific oral hygiene instructions (tooth and tongue brushing combined with flossing) to our patients with the knowledge that there is evidence to support these recommendations.

Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School, Baltimore, Maryland

© 2015 AEGIS Communications | Privacy Policy