Finkelstein 1990.

Methods	Trial design: parallel group, 5 arms Location: New Jersey, USA Number of centres: 1 Recruitment period: not reported
Participants	Inclusion criteria: adults with at least 20 uncrowned teeth and a commitment to adhere to the test protocol, occasional flossing (1 to 3 times per week) Exclusion criteria: removable prostheses, gross oral pathology, dental prophylaxis within the last 3 months Baseline plaque: not reported Baseline periodontal status: at least 10 interdental bleeding sites measured by the EIBI Age at baseline: not reported Sex: not reported Number randomised: 161 (Gp A 31; Gp B 30; Gp C 32; Gp D 33; Gp E 32) (although 161 participants were randomised, only 158 started the study) Number evaluated: 158 (Gp A 31; Gp B 30; Gp C 32; Gp D 33; Gp E 32) Smoking status: not reported
Interventions	Comparisons: manual toothbrushing versus manual toothbrushing and floss versus manual toothbrushing and a wooden interdental cleaner Gp A (n = 31 evaluated) wooden interdental cleaner (Stim‐U‐Dent), Johnson & Johnson Gp B (n = 30 evaluated) manual waxed floss (Johnson & Johnson) Gp E (n = 32 evaluated) manual toothbrushing All participants received a manual toothbrush (Oral B Indicator) and Colgate Cavity Protection toothpaste Toothbrushing was carried out "ad lib" throughout Duration of intervention: 12 weeks Other interventions (not included in the review): Gp C: essential oil mouthrinse (Listerine Antiseptic) Gp D: cetylpyridinium chloride mouthrinse (Cepacol, Merrel Dow Pharmaceutical) Training: no training was reported as having been provided. It was stated that each product was used according to the manufacturers directions. Baseline cleaning: not reported as having been undertaken Compliance assessment: not reported
Outcomes	Measurements: at week 0, week 6, and week 12 Dental plaque: Global Plaque Index Periodontal disease ‐ gingivitis: Löe & Silness Gingival Inflammation Index (VGI) and Eastman Interdental Bleeding Index (EIBI) Adverse effects: not reported Attrition: 3 randomised participants did not start the study.
Funding	Funded by a grant from Johnson & Johnson Dental Care Company; lead author J & J employee
Notes	Examiner training or calibration not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Subjects were randomly assigned to one of the five test groups…" Comment: no further information on sequence generation
Allocation concealment (selection bias)	Unclear risk	Allocation concealment not mentioned
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants not possible
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Three participants did not complete the study with no information on the reasons for lost to follow‐up; however we considered it unlikely to affect the results.
Selective reporting (reporting bias)	High risk	No standard deviations reported; unable to use data
Other bias	Unclear risk	Compliance not assessed.