Dorchester dental flossing study. Preliminary report

Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries

BACKGROUND

Dental caries (tooth decay) and periodontal diseases (gingivitis and periodontitis) affect the majority of people worldwide, and treatment costs place a significant burden on health services. Decay and gum disease can cause pain, eating and speaking difficulties, low self-esteem, and even tooth loss and the need for surgery. As dental plaque is the primary cause, self-administered daily mechanical disruption and removal of plaque is important for oral health. Toothbrushing can remove supragingival plaque on the facial and lingual/palatal surfaces, but special devices (such as floss, brushes, sticks, and irrigators) are often recommended to reach into the interdental area.

OBJECTIVES

To evaluate the effectiveness of interdental cleaning devices used at home, in addition to toothbrushing, compared with toothbrushing alone, for preventing and controlling periodontal diseases, caries, and plaque. A secondary objective was to compare different interdental cleaning devices with each other.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched: Cochrane Oral Health's Trials Register (to 16 January 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2018, Issue 12), MEDLINE Ovid (1946 to 16 January 2019), Embase Ovid (1980 to 16 January 2019) and CINAHL EBSCO (1937 to 16 January 2019). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared toothbrushing and a home-use interdental cleaning device versus toothbrushing alone or with another device (minimum duration four weeks).

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened searches, selected studies, extracted data, assessed studies' risk of bias, and assessed evidence certainty as high, moderate, low or very low, according to GRADE. We extracted indices measured on interproximal surfaces, where possible. We conducted random-effects meta-analyses, using mean differences (MDs) or standardised mean differences (SMDs).

MAIN RESULTS

We included 35 RCTs (3929 randomised adult participants). Studies were at high risk of performance bias as blinding of participants was not possible. Only two studies were otherwise at low risk of bias. Many participants had a low level of baseline gingival inflammation.Studies evaluated the following devices plus toothbrushing versus toothbrushing: floss (15 trials), interdental brushes (2 trials), wooden cleaning sticks (2 trials), rubber/elastomeric cleaning sticks (2 trials), oral irrigators (5 trials). Four devices were compared with floss: interdental brushes (9 trials), wooden cleaning sticks (3 trials), rubber/elastomeric cleaning sticks (9 trials) and oral irrigators (2 trials). Another comparison was rubber/elastomeric cleaning sticks versus interdental brushes (3 trials).No trials assessed interproximal caries, and most did not assess periodontitis. Gingivitis was measured by indices (most commonly, Löe-Silness, 0 to 3 scale) and by proportion of bleeding sites. Plaque was measured by indices, most often Quigley-Hein (0 to 5).

PRIMARY OBJECTIVE

comparisons against toothbrushing aloneLow-certainty evidence suggested that flossing, in addition to toothbrushing, may reduce gingivitis (measured by gingival index (GI)) at one month (SMD -0.58, 95% confidence interval (CI) -1.12 to -0.04; 8 trials, 585 participants), three months or six months. The results for proportion of bleeding sites and plaque were inconsistent (very low-certainty evidence).Very low-certainty evidence suggested that using an interdental brush, plus toothbrushing, may reduce gingivitis (measured by GI) at one month (MD -0.53, 95% CI -0.83 to -0.23; 1 trial, 62 participants), though there was no clear difference in bleeding sites (MD -0.05, 95% CI -0.13 to 0.03; 1 trial, 31 participants). Low-certainty evidence suggested interdental brushes may reduce plaque more than toothbrushing alone (SMD -1.07, 95% CI -1.51 to -0.63; 2 trials, 93 participants).Very low-certainty evidence suggested that using wooden cleaning sticks, plus toothbrushing, may reduce bleeding sites at three months (MD -0.25, 95% CI -0.37 to -0.13; 1 trial, 24 participants), but not plaque (MD -0.03, 95% CI -0.13 to 0.07).Very low-certainty evidence suggested that using rubber/elastomeric interdental cleaning sticks, plus toothbrushing, may reduce plaque at one month (MD -0.22, 95% CI -0.41 to -0.03), but this was not found for gingivitis (GI MD -0.01, 95% CI -0.19 to 0.21; 1 trial, 12 participants; bleeding MD 0.07, 95% CI -0.15 to 0.01; 1 trial, 30 participants).Very-low certainty evidence suggested oral irrigators may reduce gingivitis measured by GI at one month (SMD -0.48, 95% CI -0.89 to -0.06; 4 trials, 380 participants), but not at three or six months. Low-certainty evidence suggested that oral irrigators did not reduce bleeding sites at one month (MD -0.00, 95% CI -0.07 to 0.06; 2 trials, 126 participants) or three months, or plaque at one month (SMD -0.16, 95% CI -0.41 to 0.10; 3 trials, 235 participants), three months or six months, more than toothbrushing alone.

SECONDARY OBJECTIVE

comparisons between devicesLow-certainty evidence suggested interdental brushes may reduce gingivitis more than floss at one and three months, but did not show a difference for periodontitis measured by probing pocket depth. Evidence for plaque was inconsistent.Low- to very low-certainty evidence suggested oral irrigation may reduce gingivitis at one month compared to flossing, but very low-certainty evidence did not suggest a difference between devices for plaque.Very low-certainty evidence for interdental brushes or flossing versus interdental cleaning sticks did not demonstrate superiority of either intervention.Adverse eventsStudies that measured adverse events found no severe events caused by devices, and no evidence of differences between study groups in minor effects such as gingival irritation.

AUTHORS' CONCLUSIONS

Using floss or interdental brushes in addition to toothbrushing may reduce gingivitis or plaque, or both, more than toothbrushing alone. Interdental brushes may be more effective than floss. Available evidence for tooth cleaning sticks and oral irrigators is limited and inconsistent. Outcomes were mostly measured in the short term and participants in most studies had a low level of baseline gingival inflammation. Overall, the evidence was low to very low-certainty, and the effect sizes observed may not be clinically important. Future trials should report participant periodontal status according to the new periodontal diseases classification, and last long enough to measure interproximal caries and periodontitis.

The effect of behaviour modification techniques on oral hygiene and gingival health of 10-year-old Canadian children

Good oral hygiene habits in children are most desirable but are difficult to establish through conventional health education programmes. This study was designed to test the efficacy of a programme based on the use of several behaviour modification strategies. A sample of sixteen classes of 10-year-old children was randomly selected and assigned to either an experimental or control group. To monitor the oral health comparability of the groups, data were collected on caries experience, sugar intake and oral hygiene behaviour several times during the study period. The programme included the following elements: (1) dental examinations, (2) periodic visits by dental hygienists to the schools to teach brushing and flossing techniques and to monitor the quality of the children's performance, and (3) 'contracts' agreed by each child with the director of the programme and with one parent, to encourage commitment and to reinforce the desired behaviour. Loë and Silness plaque and gingival indices were used to measure the efficacy of the programme. For both indices, the difference between the mean scores of the experimental and control groups were statistically significant after a 4-month intensive phase of the programme. One year after all activities had stopped, the plaque index of the experimental group was still lower than that of the control group but insufficient to maintain a significant difference on the gingival index.

Relationship between structure and antiplaque and antimicrobial activities for a series of bispyridines

A series of bispyridines were examined for their bactericidal activities against in vitro, preformed, pure-culture plaques of selected oral plaque-forming bacteria. The antimicrobial activities of these agents were examined in relation to their molecular configurations. These studies demonstrated that the length of the interpyridine polymethylene group bridge and the length of the alkyl side chain were important determinants of antiplaque and antimicrobial efficacy. The most potent compounds of the bispyridine series were studied to determine the minimal conditions (concentration, duration, and frequency) of treatment required for likely clinical efficacy.

In vitro antiplaque activity of octenidine dihydrochloride (WIN 41464-2) against preformed plaques of selected oral plaque-forming microorganisms

The antibacterial activity of octenidine dihydrochloride (WIN 41464-2) against intact preformed in vitro plaques of four indigenous oral plaque-forming microorganisms, Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii, was studied. Both absolute (plaque bactericidal index) and relative (chlorhexidine coefficient) indices of antiplaque efficacy were established. Octenidine dihydrochloride compared favorably with chlorhexidine digluconate with respect to overall antiplaque potency in this in vitro plaque bactericidal model. These data indicate that prudent selection of treatment concentration and duration and frequency of exposure should provide an effective means to aid in controlling dental caries and Actinomyces-associated disease in vivo.

Frequency and distribution of proximal overlappings on posterior bitewing radiographs

4374 proximal surfaces on 791 posterior bitewing radiographs were classified according to overlappings. Six categories were used: 1) no overlapping, 2) blurred contact areas, 3) less than half of the enamel overlapped, 4) more than half of the enamel overlapped, 5) dentin overlapped, and 6) unclassifiable overlappings. Filled surfaces and surfaces not in contact were excluded. Only 19% of the surfaces did not have overlappings 65% exhibited mild overlappings (categories 2 and 3), and 16% severe overlappings (categories 4, 5 and 6). The frequencies of no overlappings varied from 7% to 40% for single tooth surfaces. The relationship between distribution of overlappings and tooth surfaces was statistically significant at the 0.05% level. Principles of excluding overlapping surfaces have been inconsistent in previous epidemiologic studies and clinical trials. The use of exact criteria for exclusion is recommended.

Plaque removal by dental floss or toothpicks. An intra-individual comparative study

The amount of plaque accumulation was assessed in an intraindividual study comprising 10 individuals. During different 2-week periods, the test subjects used nylon floss (unwaxed, waxed and specially treated), silk floss (unwaxed and waxed), Superfloss or triangular toothpicks for interdental tooth cleaning. Only teeth in contact with neighboring ones and with open interdental spaces were included in the study. The plaque removal of the interdental aids used was registered by estimating the amount of plaque present at the end of each experimental period according to a Plaque Index (Silness & Löe 1964) modified for plaque registration on 10 surface units around each tooth. In general, dental floss had a higher plaque removing potential than triangular toothpicks, especially on lingual axial surfaces.

Effects of supervised daily dental plaque removal by children: II. 24 months' results

After two school years of a supervised daily plaque-removal program in school, children in the treatment group showed a significant reduction in plaque and gingival inflammation scores compared with children in the control group. However, differences between groups in terms of plaque and gingivitis scores virtually disappeared during the summer vacation. The increment of dental caries was lower in the treatment group than in the control group, but the reduction, which averaged about 20 percent, was not statistically significant either for teeth or for surfaces. Although the 24-month findings of the present study indicate some degree of success in reducing plaque and gingivitis and a marginal effect in reducing the incidence of dental caries among children who engaged in daily, supervised plaque-removal in school, obvious drawbacks limit the value of this regimen.

In vitro evaluation of three iodine-containing compounds as antiplaque agents

The antibacterial activity of three iodine-containing compounds was determined for strains of four dental plaque-forming microorganisms, using an in vitro preclinical plaque model system. Solutions of inorganic iodine, povidone-iodine, and Wescodyne were tested for antiplaque activity against preformed plaques of a number of strains of Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii. Solutions of inorganic iodine were more effective as antiplaque agents, with respect to minimal bactericidal concentration and time and frequency of treatments, than solutions of Wescodyne and povidone-iodine. Inorganic iodine appeared to be particularly effective against the most cariogenic (S. mutans) and periodontopathic (A. viscosus) organisms while allowing survival of the least orally pathogenic plaque-forming microorganism (S. sanguis). It is suggested that topical application of solutions of inorganic iodine may be useful in controlling dental caries and actinomyces-associated periodontal disease.

Effect of interdental flossing on the incidence of proximal caries in children

A clinical study was designed to evaluate the effect of frequent interdental flossing on the incidence of proximal dental caries. School children from a fluoride-deficient area were studied after clinical and radiographic examinations. Each child had at least one contralateral pair of intact, contacting proximal tooth surfaces between the distal surface of the primary cuspid and the mesial surface of the first permanent molar. Randomly selected test surfaces were flossed each school day with unwaxed dental floss by researchers. The contralateral surfaces served as controls. Flossing was done for eight months, discontinued for four months, and reinstituted for another eight months. A significant reduction in the incidence of proximal caries resulted.