Interdental Cleaning Devices in Addition to Toothbrushing: a Cochrane Systematic Review

Objectives: To evaluate the effectiveness of mechanical interdental cleaning in addition to toothbrushing, compared with toothbrushing alone, for the prevention and control of periodontal diseases.
Methods: Four databases were searched up to 31 January 2018, for randomised controlled trials. Cochrane methods were used for all data screening, data extraction and risk of bias assessments of studies. Random effects models using standardised mean differences (SMD) were used to pool data for different gingival indices. Heterogeneity was investigated where there were sufficient data.
Results: We included 32 RCTs (3591 randomised participants) that assessed or compared methods of mechanical interdental cleaning. All the studies were assessed as high risk of performace bias.

When comparing interventions with toothbrushing alone, there is very-low certainty evidence of a benefit at one month in reducing gingivitis for floss (SMD -0.60, 95% confidence interval (CI) -1.10 to -0.10; eight trials, 586 participants), interdental brushes (SMD -0.74, 95% CI -1.17 to -0.32; two trials, 93 participants) and wooden cleaning sticks. There was no evidence that rubber tooth-cleaning sticks or oral irrigation were effective.

For head-to-head interventions there is some low-certainty evidence of a small benefit for using interdental brushes rather than flossing for gingivitis at one month (SMD -0.40, 95% CI -0.64 to -0.17; five parallel-group trials, 290 participants; SMD -0.72, 95% CI -1.41 to -0.04; three split-mouth trials, 66 participants).
There was no evidence of a difference for probing pocket depth for any comparison.
Conclusions: There is very low-certainty evidence of a small benefit for additional use of floss, interdental brushes or wooden cleaning sticks to reduce gingivitis, compared to toothbrushing alone. There is low-certainty evidence that interdental brushes may be more effective than floss for reducing gingivitis. The long-term significance of these benefits is unclear as few of the studies evaluated pocket probing depth as a measure of periodontitis and none assessed interproximal caries.