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Study comparing the effectiveness of manual flossing vs flossing with the floss handle FlossGrip

Crossed study carried out in 1994 by the Belgian UCL University


1. Introduction

Since  the role of the dental plaque in the gingival inflammation is well established, the need for a daily elimination of this one remains the only means of prevention and cure. The use of the toothbrush is already well accepted by the population and close to X% of the people say to use it every day.

 2. Material and method

The goal of this study was to compare the effectiveness of the dental floss alone with the dental floss fixed on a floss handle (FlossGrip).

Thirty students were invited to take part in this single blind study. The criteria of inclusions were the following: presence of minimum 5 teeth per arcade, absence of great restorations or crowns, to have a frequency of one brushing per day. Exclusion criteria involved the use of oral antiseptics or antibiotics within 15 days before the start of the study.

The first visit consisted of a statement of the inflammatory index (pi, PBI), after which the subjects underwent a full scaling as well as a polishing. They were explained in details how to control the plaque at home. They were asked to reproduce the taught brushing technique immediately after demonstration in order to make sure of the correct handling of the brush, the dental floss and the flosser.

The students were divided into 2 groups randomly. The first group received a brush, a waxed dental floss and two tubes of toothpaste (Sensodyne®), the other receiving a flosser (F1ossgrip) on top of it.

It was asked to them to carry out at least one complete brushing per day (toothbrush + floss, or toothbrush  + flosser).

The first control was carried out after 3 weeks. A statement of the plaque index (PI) and papillary bleeding index (PBI) were made. The students having used the flosser during the first 3 weeks were requested to give it back. In the same way a flosser was given to the students who had not employed it for this period.

The second control took place after six weeks. Again the plaque index and papillary bleeding index were mesured. The students also had to fill in a questionnaire making it possible to analyze the conformity (“compliance”).

This same questionnaire was submitted to them 3 months after the end of the study.

3. Results

At the beginning, thirty students were seen. One notes an average papillary bleeding index of 1.61 in the group L, and of 1.50 in group 2. These indexes were subjected to the T-test which gives us a nonsignificant difference. We can thus say that they are two homogeneous groups.

After 3 weeks, we observed a significant reduction in the two groups. Group 1 (without flosser) passes from 1.61 to 1.11 (- 0.50); group 2 (with flosser) passes from 1.50 to 1.10 (- 0.40). Let us note that in group 1, three students did not come to the appointment for the control.

The study being crossed, after this first period, the students of group 1 received the flosser, the students of the second group returned theirs.

With the second control, we observe a light nonsignificant increase in the papillary bleeding index. Group 1 (with flosser) passes from 1.11 to 1.16 (+0.05); group 2 (without flosser) passes from 1.10 to 1.17 (+ 0.07). The slight (but not significant) increase of the papillary bleeding index probably reveals a bit of weariness on the part of the students. One student of group 2 did not come to the control. We thus finished the study with 26 cases.


Group 1



Group 2


Average papillary bleeding index



Average papillary bleeding index


T = 0







Manual Flossing



Flossing with FlossGrip


T = 3 weeks







Flossing with FlossGrip



Manual flossing


T = 6 weeks






The t-test expresses a significant difference between the 2 groups after the beginning of the use of the floss. There is no statistically significant difference between cleaning inter dental spaces with the floss alone and cleaning with FlossGrip, neither between the two groups (NS), nor inside the groups (NS).

Our comments about this study: It's well known that flossing manually is very effective. But the problem is that it's very laborious. This study demonstrates that flossing with FlossGrip is as efficient as by hand. Interesting to note: After the first three weeks, three students, which means 20% of the group having to floss manually, didn't come back. When the second group had to floss by hand, one student resigned. Each time a group was using FlossGrip, no one abandoned.


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1030 Brussels

Belgium (EUROPE)