This review, carried out by the Cochrane Oral Health Group, seeks to evaluate the effects of interdental (between the teeth) brushing in addition to toothbrushing as compared with toothbrushing on its own or toothbrushing plus flossing for the prevention and control of periodontal (gum) diseases, dental plaque (a sticky film containing bacteria) and dental caries (tooth decay).
Gum disease and tooth decay are the main reasons for tooth loss. Unless brushed away, plaque can build up on the teeth. A build up of plaque can lead to gum inflammation and gum disease and is also a key factor in the development of tooth decay.
Conventional toothbrushing alone is not very effective at removing plaque between teeth. Dental floss has been used for many years together with toothbrushing for removing dental plaque in between teeth. However, recently, interdental brushes to use between the teeth have been developed and many people find them easier to use than floss. If interdental brushes are to be used there must be enough space between the teeth to enable this.
Interdental brushes are small-headed toothbrushes available in a range of different widths to match the space between teeth. They can be cone shaped or cylindrical. Brushes for use for cleaning around implants have coated wire to avoid scratching them or causing a shock.
Together with dental floss interdental brushes are one of the most commonly recommended, advertised and available aids for cleaning between the teeth.
The evidence on which this review is based was current as of 7 March 2013. Seven studies with a total of 354 participants were included in this review. Participants were aged 16 years and over and had teeth. In terms of deciding which studies to include in this review there was no distinction made on the basis of race, gender, jobs (socioeconomic status), place, background exposure to fluoride, initial health status, setting or time of the intervention. Studies were excluded from the review if the majority of participants had any orthodontic appliances (braces), if participants were selected on the basis of special health conditions or if the majority of participants had severe gum disease.
There is some very low-quality evidence that using interdental brushes plus toothbrushing is more beneficial than toothbrushing alone for plaque and gingivitis at one month. There is also low-quality evidence that using interdental brushes reduces gingivitis (gum inflammation) by 52% when compared with flossing at one month. There was insufficient evidence to claim a benefit for either interdental brushing or flossing for plaque.
None of the studies reported on tooth decay as none were long enough for the changes brought about by early tooth decay between teeth to be detected or found. Three studies reported that no adverse effects or harms were observed or reported during the study. Two other studies provided some data on adverse effects/harms/problems ranging from difficulties manipulating floss, reaching back teeth, interdental brushes distorting and buckling and also (noted to be the most serious) the fact that floss can make gums sore, however we could not formally analyse the data as studies did not provide enough detail. Two studies did not report whether adverse events occurred.
Quality of the evidence
The quality of the only study to compare toothbrushing with interdental brushing and toothbrushing alone was assessed as being very low. The quality of evidence for the comparison between interdental brushing and flossing both in addition to toothbrushing was low. No studies reported the development of tooth decay.
Only one study looked at whether toothbrushing with interdental brushing was better than toothbrushing alone, and there was very low-quality evidence for a reduction in gingivitis and plaque at one month. There is also low-quality evidence from seven studies that interdental brushing reduces gingivitis when compared with flossing, but these results were only found at one month. There was insufficient evidence to determine whether interdental brushing reduced or increased levels of plaque when compared to flossing.
Effective oral hygiene is a crucial factor in maintaining good oral health, which is associated with overall health and health-related quality of life. Dental floss has been used for many years in conjunction with toothbrushing for removing dental plaque in between teeth, however, interdental brushes have been developed which many people find easier to use than floss, providing there is sufficient space between the teeth.
To evaluate the effects of interdental brushing in addition to toothbrushing, as compared with toothbrushing alone or toothbrushing and flossing for the prevention and control of periodontal diseases, dental plaque and dental caries.
We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 7 March 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 2), MEDLINE via OVID (1946 to 7 March 2013), EMBASE via OVID (1980 to 7 March 2013), CINAHL via EBSCO (1980 to 7 March 2013), LILACS via BIREME (1982 to 7 March 2013), ZETOC Conference Proceedings (1980 to 7 March 2013) and Web of Science Conference Proceedings (1990 to 7 March 2013). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the metaRegister of Controlled Trials (http://www.controlled-trials.com/mrct/) for ongoing trials to 7 March 2013. No restrictions were placed on the language or date of publication when searching the electronic databases.
We included randomised controlled trials (including split-mouth design, cross-over and cluster-randomised trials) of dentate adult patients. The interventions were a combination of toothbrushing and any interdental brushing procedure compared with toothbrushing only or toothbrushing and flossing.
At least two review authors assessed each of the included studies to confirm eligibility, assessed risk of bias and extracted data using a piloted data extraction form. We calculated standardised mean difference (SMD) and 95% confidence interval (CI) for continuous outcomes where different scales were used to assess an outcome. We attempted to extract data on adverse effects of interventions. Where data were missing or unclear we attempted to contact study authors to obtain further information.
There were seven studies (total 354 participants analysed) included in this review. We assessed one study as being low, three studies as being high and three studies as being at unclear risk of bias. Studies only reported the clinical outcome gingivitis and plaque data, with no studies providing data on many of the outcomes: periodontitis, caries, halitosis and quality of life. Three studies reported that no adverse events were observed or reported during the study. Two other studies provided some data on adverse events but we were unable to pool the data due to lack of detail. Two studies did not report whether adverse events occurred.
Interdental brushing in addition to toothbrushing, as compared with toothbrushing alone
Only one high risk of bias study (62 participants in analysis) looked at this comparison and there was very low-quality evidence for a reduction in gingivitis (0 to 4 scale, mean in control): mean difference (MD) 0.53 (95% CI 0.23 to 0.83) and plaque (0 to 5 scale): MD 0.95 (95% CI 0.56 to 1.34) at one month, favouring of use of interdental brushes. This represents a 34% reduction in gingivitis and a 32% reduction in plaque.
Interdental brushing in addition to toothbrushing, as compared with toothbrushing and flossing
Seven studies provided data showing a reduction in gingivitis in favour of interdental brushing at one month: SMD -0.53 (95% CI -0.81 to -0.24, seven studies, 326 participants, low-quality evidence). This translates to a 52% reduction in gingivitis (Eastman Bleeding Index). Although a high effect size in the same direction was observed at three months (SMD -1.98, 95% CI -5.42 to 1.47, two studies, 107 participants, very low quality), the confidence interval was wide and did not exclude the possibility of no difference. There was insufficient evidence to claim a benefit for either interdental brushing or flossing for reducing plaque (SMD at one month 0.10, 95% CI -0.13 to 0.33, seven studies, 326 participants, low-quality evidence) and insufficient evidence at three months (SMD -2.14, 95% CI -5.25 to 0.97, two studies, 107 participants very low-quality evidence).