Efficiency of Three Interdental Plaque Control Aids (Dental Floss, Water Flosser, and Interdental Brush) as an Adjunct to Toothbrushing in Children

ABSTRACT

Introduction

General well-being of an individual, particularly oral health, depends on the maintenance of optimal oral hygiene. Evidence-based research has established the role of plaque biofilm as an etiologic factor that increases the risk of developing oral diseases such as dental caries and gingival and periodontal diseases. Brushing with either manual or mechanical toothbrushes is most commonly practiced for the removal of plaque, but its efficiency is limited to surfaces it can access, i.e., facial, lingual, and occlusal surfaces of the teeth. During the mixed dentition period, there is closure of all physiological spaces and establishment of tight proximal contact, increasing the risk of proximal caries and gingival diseases if appropriate plaque control measures are not undertaken.

Numerous interdental cleaning aids are available in the market, such as dental floss, interdental brushes, wooden interdental aids, and oral irrigators, to support patients' self-care needs. Dental floss is used along with toothbrushing for interdental plaque removal in both primary and permanent dentition. It may act differently on the primary tooth due to its distinct anatomy—bulbous crowns, broad, flat contact areas, and cervical constrictions. Floss types include waxed, unwaxed, bonded, unbonded, and those with drug additives, with handles such as stick floss of F-type and Y-type.

Interdental brushes are found to be effective in removing interdental plaque, as recommended by the European Federation of Periodontology 2015 workshop. They can reach interdental grooves or fissures that are not physically accessible to other devices, are safe and easy to use, and their selection depends on individual needs. Oral irrigators, such as the dental water jet—first introduced in 1962 by a Colorado dentist and now known as the water flosser—have the advantage of reaching inaccessible areas in both open and closed dentitions. They are effective in plaque removal, can be used with chemical plaque control agents, and are considered to be three times more effective than manual brushing. Water flossers are also useful for children with special healthcare needs.

However, complete removal of plaque biofilm remains a challenge and depends on a child's manual dexterity, devices used, skills acquired through training, appropriate technique, and frequency of oral hygiene practice. With this background, the present study was undertaken to assess and compare the plaque removal efficiency of three interdental cleaning devices as an adjunct to brushing in children with mixed dentition.

Materials and methods

The present study was conducted by the Department of Pedodontics and Preventive Dentistry. A total of 308 children were screened, and 100 children aged 6–12 years with a minimum of 20 scorable teeth, free of systemic diseases and willing to participate with informed consent, were selected. Children with oral lesions, dental caries, or developmental disturbances of the teeth or systemic diseases affecting oral hygiene practices were excluded.

At the initial visit, oral hygiene status was assessed and scored using the Rustogi Modified Navy Plaque Index (RMNPI) following standard protocols. Two-tone plaque disclosing solution was applied to all tooth surfaces using a cotton swab and left for 1 minute. Petroleum jelly was applied to the oral mucosa to prevent staining. After rinsing with water spray and suction for 30 seconds, plaque staining was evaluated. Each of the nine areas on buccal and lingual surfaces (including marginal and approximal regions) was scored, and the mean was calculated. Intraoral photographs were taken to reconfirm scores.

Children were randomly divided into four groups of 25 each and trained in brushing and the use of interdental aids:

Group I: Interdental floss (STIM flexible)

Group II: Water flosser (Oracura−Prima)

Group III: Interdental brush (STIM−Proxa angular brush)

Group IV: Toothbrushing alone (Colgate Junior toothbrush)

All groups practiced their assigned method for 4 weeks. Oral hygiene status was reassessed after 4 weeks using the same methodology. Data were tabulated in Microsoft Excel and analyzed using SPSS v22.0. Paired t-test was used for within-group comparison, analysis of variance (ANOVA) for between-group comparison, and Bonferroni test for multiple comparisons. A p-value of <0.05 was considered statistically significant.

Results

The results showed a significant reduction in plaque scores from baseline following toothbrushing (p = 0.000). No significant difference in plaque removal efficiency was observed between toothbrushing and flossing (p > 0.05), nor between floss, interdental brush, and oral irrigator (p > 0.05). However, oral irrigators and interdental brushes were significantly more effective than toothbrushing alone (p = 0.0087 and p = 0.0027, respectively).

Conclusion

Adjunctive aids such as dental floss, interdental brushes, and oral irrigators are recommended along with toothbrushing for better plaque control and prevention of caries and gingival diseases in children.

How to cite this article

George A, Mungara J, Vijayakumar P, et al. Efficiency of Three Interdental Plaque Control Aids (Dental Floss, Water Flosser, and Interdental Brush) as an Adjunct to Toothbrushing in Children. Int J Clin Pediatr Dent 2025;18(6):637–640.

INTRODUCTION

The general well-being of an individual, particularly oral health, depends on the maintenance of optimal oral hygiene. Evidence-based research has established the role of plaque biofilm as an etiologic factor that increases the risk of developing oral diseases such as dental caries and gingival and periodontal diseases.^1,2

Brushing with either manual or mechanical toothbrushes is the most commonly practiced method for plaque removal, but its efficiency is limited to surfaces it can access—namely, the facial, lingual, and occlusal surfaces of the teeth. During the mixed dentition period, closure of all physiological spaces and establishment of tight proximal contact increase the risk of developing proximal caries and gingival diseases if appropriate plaque control measures are not undertaken.

Numerous interdental cleaning aids are available in the market—such as dental floss, interdental brushes, wooden interdental aids, and oral irrigators—to support patients' self-care needs.

Dental floss is used along with toothbrushing for interdental plaque removal in both primary and permanent dentition. It may act differently on primary teeth due to their distinct anatomy—bulbous crowns, broad, flat contact areas, and cervical constrictions. Various types of floss available include waxed, unwaxed, bonded, and unbonded dental floss; floss with drug additives; and handled versions such as stick floss of F-type and Y-type.

Interdental brushes have been found to be effective in removing interdental plaque, as recommended by the 2015 European Federation of Periodontology workshop.³ The main advantage of interdental brushes is that they can reach interdental grooves or fissures not physically accessible by other interdental cleaning devices. They are safe and easy to use, and the choice of brush depends on the individual's specific needs.

Oral irrigators, such as the dental water jet—first introduced in 1962 by a Colorado dentist to improve patients' oral hygiene and now known as the water flosser⁴—offer the advantage of reaching inaccessible areas in both open and closed dentitions. They are effective in plaque removal, can be used with chemical plaque control agents, and are considered to be three times more effective than manual brushing. Water flossers are particularly useful for children with special health care needs.

However, complete removal of plaque biofilm remains a challenging task,^5,6 and depends on the child's manual dexterity, the type of device used, skills acquired through training, and appropriate technique, time, and frequency of oral hygiene practices.⁷

With this background, the present study was undertaken to assess and compare the plaque removal efficiency of three interdental cleaning devices as an adjunct to brushing in children with mixed dentition.

MATERIALS AND METHODS

The present study was conducted by the Department of Pedodontics and Preventive Dentistry.

A total of 308 children were screened, and 100 children within the age-group of 6–12 years, with a minimum of 20 scorable teeth, free of any systemic diseases, and willing to participate with informed consent, were included. Children free of any oral lesions and dental caries were selected after excluding those with developmental disturbances of teeth or any systemic disease that interferes with oral hygiene skills and practices.

At the initial visit, oral hygiene status was assessed and scored using the Rustogi Modified Navy Plaque Index (RMNPI) by following standard protocols (Fig. 1). Baseline plaque scores were recorded using the RMNPI index. A two-tone plaque disclosing solution was applied using a cotton swab on all tooth surfaces and left for 1 minute. Petroleum jelly was applied to the oral mucosa beforehand to prevent staining. The tooth surfaces were gently rinsed for 30 seconds using a water spray and high-volume suction, and changes were observed.

Fig. 1:

Rustogi Modified Navy Plaque index (RMNPI)

The stained plaque on all tooth surfaces was scored individually, and the mean score was calculated. Intraoral photographs were taken for later reference and to reconfirm the plaque scores. Plaque was evaluated as either present or absent (one or zero) on each of the nine areas of the buccal and lingual tooth surfaces (including marginal and approximal areas).

Children were divided into four groups of 25 each using computer-generated randomization and were trained in correct brushing techniques and the use of interdental cleaning aids:

• Group I: Interdental floss (STIM Flexible)

• Group II: Water flosser (Oracura−Prima)

• Group III: Interdental brush (STIM−Proxa Angular Brush)

• Group IV: Toothbrushing alone (Colgate Junior Toothbrush)

Participants were instructed to practice their assigned method after brushing for a period of 4 weeks. Oral hygiene status was reassessed after 4 weeks using the same methodology.

The effectiveness was evaluated based on the reduction in plaque scores compared with baseline values. All observations were tabulated using Microsoft Excel, and statistical analysis was performed using a paired t-test for within-group comparisons, ANOVA for between-group comparisons, and multiple comparisons with the Bonferroni test using SPSS software version 22.0. A p-value of < 0.05 was considered statistically significant.

RESULTS

The study showed a significant reduction in plaque scores from baseline following toothbrushing (p = 0.000).

There was no significant difference in plaque removal efficiency between toothbrushing and flossing (p > 0.05). Similarly, no significant difference was observed among flossing, interdental brushing, and oral irrigation (p > 0.05). However, oral irrigators and interdental brushes were significantly more effective in plaque control than toothbrushing alone (p = 0.0087 and p = 0.0027, respectively) (Tables 1 and 2) .

Table 1:

Mean plaque values pre- and post-use of stick floss, water flosser, interdental brush when used as an adjunct to toothbrushing, and toothbrushing alone

Device used	Preoperative change	Postoperative change	Mean change
Stick floss group	2.01 ± 0.604	0.15 ± 0.336	1.86 ± 0.691
Water flosser	2.15 ± 0.436	0.05 ± 0.047	2.10 ± 0.439
Interdental brush	2.15 ± 0.556	0.05 ± 0.067	2.11 ± 0.560
Toothbrushing alone	1.84 ± 0.422	0.13 ± 0.063	1.70±0.427

Table 2:

The comparative evaluation of the plaque removal efficacy of interdental cleaning aids along with brushing

Group	Preoperative mean score	Postoperative mean score	Mean change in plaque score	Significance
I	2.01 ± 0.604	0.15 ± 0.336	1.866 ± 0.6916	I vs II III (p > 0.05), IV
II	2.15 ± 0.436	0.05 ± 0.047	2.100 ± 0.4392	II vs I III (p > 0.05) II vs IV (p = 0.0087*)
III	2.15 ± 0.556	0.05 ± 0.067	2.110 ± 0.5607	III vs I II (p > 0.05) III vs IV (p = 0.0027*)
IV	1.84 ± 0.422	0.13 ± 0.063	1.703 ± 0.4274	IV vs I (p > 0.05) II (p = 0.0087*) III (p = 0.0027*)

DISCUSSION

Prevention and control of oral diseases are integral to pediatric dental practice. Maintaining oral health through appropriate hygiene strategies helps prevent dental caries and gingival diseases. Brushing—whether manual or powered—is the most commonly practiced method. However, interproximal sites are at higher risk due to varied gingival and occlusal changes, necessitating the use of adjunct interdental aids such as dental floss, interdental brushes, and oral irrigators.

Most prior research has focused on adult populations, and there is a scarcity of literature evaluating the effectiveness of interdental aids in children. This study aimed to evaluate and compare the efficacy of three interdental cleaning devices (floss, interdental brush, and oral irrigator) among 100 children aged 6–12 years. Participants were divided into four groups (three experimental and one control).

Baseline plaque scores were recorded using the Rustogi Modified Navy Plaque Index. All participants were taught the modified Bass brushing technique and trained to use their assigned interdental device. After 4 weeks of use, plaque scores were reassessed using the same index. Data were statistically analyzed using paired t-tests, one-way ANOVA, and Bonferroni tests (SPSS version 22.0).

Children above 6 years were included as they possess improved manual dexterity and cognitive ability for using interdental aids. The RMNPI was selected due to its ability to assess both marginal and interproximal plaque.

Flossing showed significant plaque control efficacy (p = 0.000), similar to findings by Kiran et al.⁸ and Kleber et al.⁹ In contrast, studies by Berchier et al., Sambunjak et al., Kiger et al., and Graziani et al.^10–12 reported no additional benefit of flossing. Our differing results may be due to the older age-group, better dexterity, and easier floss use via floss holders.

Interdental brushing also showed significant efficacy, consistent with Graziani et al.,¹³ Kiger et al.,¹² Jackson et al.,¹⁴ Rosing et al.,¹⁵ and Jared et al.¹⁶ High patient acceptance and ease of use contribute to their superiority.

Water flossers significantly reduced plaque, in line with studies by Cutler et al.,¹⁷ Al-Mubarak et al.,¹⁸ Newman et al.,¹⁹ Rosema et al.,²⁰ Goyal et al.,²¹ and Sharma et al.²² However, Husseini et al.²³ reported no visible benefit. Ciancio et al.²⁴ explained that oral irrigators' dual action (pulsation and pressure) dislodges supragingival plaque and flushes subgingival debris.

Brushing alone was also effective, as demonstrated by Slot et al.²⁵ and Van der Weijden et al.²⁶

Dental floss performed better than toothbrushing but was less effective than oral irrigators and interdental brushes, though not significantly. Water flossers and interdental brushes were equally effective and significantly superior to brushing alone. This aligns with Goyal et al.²¹ but contrasts with Lyle et al.,²⁷ who found irrigators more effective. Other researchers (Cutler et al.¹⁷, Al-Mubarak et al.,¹⁸ Barnes et al.,²⁸ Rosema et al.²⁰) noted irrigators' superiority over both brushing and flossing.

Some studies (Imai et al.,²⁹ Noorlin et al.³⁰) found no difference between floss and interdental brushes, while others (Christou et al.,³¹ Jackson et al.,¹⁴ Rosing et al.¹⁵) reported that interdental brushes were superior.

The current findings show that all tested devices improved plaque scores after 4 weeks. Flossing was as effective as brushing; however, interdental brushes and oral irrigators yielded better outcomes, supporting their use as adjuncts. Study limitations include short duration and limited sample size. Further long-term research is warranted.

CONCLUSION

• Dental floss showed significant plaque control efficiency.

• The interdental brush showed significant plaque control efficiency.

• The water flosser showed significant plaque control efficiency.

• Toothbrushing showed significant plaque control efficiency.

• Plaque removal efficiency of dental floss and toothbrushing showed no significant difference.

• No significant difference was found among dental floss, water flosser, and interdental brush.

• Water flosser and interdental brush were significantly superior to brushing alone.

These findings emphasize the importance of interdental cleaning aids in pediatric plaque control. The adjunctive use of floss, interdental brushes, or oral irrigators along with toothbrushing is recommended for preventing caries and gingival diseases in children.

ORCID

Annam George https://orcid.org/0000-0002-9662-1906

Deebiga Karunakaran https://orcid.org/0000-0002-1345-0700