Introduction: The maintenance of good oral hygiene among orthodontic patients is a challenge. The purpose of this study was to compare the oral hygiene habits, gingival health, and preference of orthodontic patients when using a floss aid compared to conventional finger flossing with a floss threader. Methods: Thirty-four adolescent and young adult patients with fixed orthodontic appliances and poor oral hygiene were enrolled from the Loma Linda University Graduate Orthodontic Clinic. This was a single blind crossover study. The patients were randomly assigned to one of two treatment groups (floss aid or finger floss) in phase I. After prophylaxis, subjects were instructed to use the floss aid or finger floss once a day and continue brushing for 4-5 weeks. Patients then had a washout period of 4-5 weeks. In phase II, patients were assigned to the alternate treatment group for another 4-5 weeks. Clinical measurements of gingival index (mGI), plaque index (mQPI) and full mouth bleeding score (FMBS) were recorded at baseline prior to prophylaxis and after 4-5 weeks of each treatment. A survey to assess oral hygiene habits and product preference was given at the end of each treatment and results were analyzed using the McNemar and McNemar-Bowker test. Statistical analysis for mGI, mQPI and FMBS was performed

using Paired Sample t-test and a mixed model procedure. Results: The Paired Sample t-test indicated no significant difference between baseline scores for mGI, mQPI and FMBS at phase I and phase II. The mixed model procedure analyzed data for the effects of time, treatment and treatment sequence on mGI, mQPI and FMBS. Results revealed statistically significant improvements in mGI, mQPI and FMBS for both treatment groups over time, with the floss aid showing more improvement (P <0.05). Percent frequency of mGI and mQPI scores after treatment for test (floss aid) and control (finger floss) groups showed improvements in both interproximal and middle regions of the teeth. Treatment sequence was not statistically significant for any of the indices. The McNemar test indicated a statistically significant difference in the time to complete flossing between the two treatment groups (P =0.002). After using both the test and control products, 85.3% of subjects preferred the test product. Conclusions: Both the floss aid and conventional finger flossing were effective at reducing plaque, gingival inflammation and bleeding over time. Although the statistical analysis model showed more improvement in all indices with the floss aid, the improvements were small and not clinically significant.

LLU Discipline

Orthodontics and Dentofacial Orthopedics


Orthodontics and Dentofacial Orthopedics


School of Dentistry

First Advisor

Neufeld, Roland

Second Advisor

Kim, Yoon Jeong

Third Advisor

Leggitt, V. Leroy

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Oral Hygiene - Instrumentation; Dental Devices - Home Care; Dental Plaque - Prevention & Control; Dental Plaque Index; Gingivitis - Prevention & Control; Periodontal Index

Subject - Local

Flossing; Single Blind Crossover Study; Floss Aid; Finger Floss; Oral Hygiene Habits



Page Count


Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives