Van Strydonck 2008.

Study characteristics
Methods	Study design: parallel (3 arms 2 arms are relevant to this review) Location: the Netherlands. Department of Periodontology, Academic Centre for Dentistry (ACTA) Number of centres:1 Study duration: Recruitment period is not reported. Study duration and duration of rinsing was 6 weeks
Participants	Participants: non‐dental students at the University of Amsterdam Inclusion criteria: quotes: "Good general health, no medical or dental history or medication which might interfere with the outcome or the progress of the study" and "a minimum of 18 scorable natural teeth excluding third molars or crowned teeth with porcelain or gold restorations. To be enrolled in the study, the subjects were required to have a minimum of 40% bleeding sites as determined by the Bleeding on Marginal Probing Index (BOMP)" Exclusion criteria: quote: "Subjects were excluded if they had any physical limitations or restrictions which might preclude normal toothbrushing skills. They were also excluded if they had used an oral CHX product or had taken a systemic antibiotic or antiinflammatory drug for 3 consecutive days within the previous 3 months. Subjects with removable prostheses or orthodontic appliances were not allowed to participate" Baseline gingivitis: Bleeding on Marginal Probing Index (Van der Weijden 1994) Gp A: 1.21 (SD 0.24), Grp B: 1.22 (SD 0.25), Gp C: 1.26 (SD 0.26) Age at baseline: mean Gp A: 21, Gp B: 22, Gp C: 23. Age range 18‐65 years Gender: Gp A: male 21% female 79%, Gp B: male 26% female 74%, Gp C: male 37% female 63% Number randomised: 150 (Gp A 50, Gp B 50, Gp C 50) Number evaluated: 140 (Gp A 47, Gp B 47, Gp C 46)
Interventions	Comparison: (CHX mouthrinse and template control brush) versus (template control brush) versus (template test brush (with slow‐releasing delivery of 124 mg CHX digluconate))* Gp A (n = 50): template control brush and CHX rinse 0.2% CHX digluconate: 10 mL, twice daily, 60 seconds and brush twice daily for 1 min without dentifrice Gp B (n = 50): template control brush: brush twice daily for 1 min without dentifrice *GP C (n = 50): test brush (with slow‐releasing delivery of 124 mg CHX digluconate): brush twice daily for 1 min without dentifrice. We excluded this arm from our risk of bias and analysis Prophylaxis at baseline: quote: "At baseline subjects received a supragingival prophylaxis to render them plaque and stain free" OHI: quote "..instructed to brush twice daily without a dentifrice for 1 min (in the morning and in the evening)" Non‐supervised rinsing Timing of mouthrinsing in relation to toothbrushing: rinsed twice daily after toothbrushing without a dentifrice Postrinsing instructions: quote: "subjects were asked to refrain from rinsing eating or drinking for 30 mins after using their assigned product"
Outcomes	Gingivitis (gingival bleeding: Bleeding on Marginal Probing Index (Saxton & Van der Ouderaa, Van der Weijden 1994); plaque (Silness & Löe 1964, Danser 2003); stain (Gründermann Modified Stain Index (Gründermann 2000) all measured at 3 and 6 weeks
Funding	Quote: "This study was supported by a grant from Oral‐B Laboratories, Belmont, CA, USA." GSK provided the Corsodyl mouthrinse
Notes	No dentifrice was used when toothbrushing Sample size calculation: very detailed description provided. Quote: ".... a sample size of 45 subjects per treatment group was needed to ensure an 80% (power = 1‐β) or greater chance of detecting differences of ≥0.11 whole‐mouth BOMP units" Adverse effects: apart from tooth staining, quotes: "no adverse events were reported" and "No differences were detected in the proportion of oral tissue abnormalities among the groups, with the exception of the tongue. Changes noted were the presence of stain or discoloration on the tongue. Treament Ctb+R (Gp A) yielded a statistically significantly (P=0.0001) greater proportion of abnormal observations than treatments Ttb (Gp C, excluded from this review) and Ctb (Gp B)" Declarations/conflicts if interest: quote: "The authors declare that they have no conflict of interests"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomisation was performed using a computer‐generated list of random‐numbers" Comment: adequate method of random sequence generation
Allocation concealment (selection bias)	Unclear risk	The study co‐ordinator was responsible for allocation concealment Comment: not enough information is provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants is not possible due to the interventions being tested: template toothbrush versus template toothbrush and CHX mouthrinse and this could have affected participants' oral health behaviours and hence the outcome. The direction of this potential bias is unclear
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "Study products were coded and distributed to the subjects in a location away from the examiners to ensure and maintain blinding.... the examiners were blind to treatment randomization and records of earlier examinations were not available at the time of re‐examinations... One examiner assessed all plaque scores and performed all stain evaluations... Another examiner assessed all the bleeding scores using BOMP and all safety evaluations" Quote: "The mean stain scores for treatment Ctb+R (CHX) were statistically greater (P=0.0001) than for treatments Ttb (CHX template toothbrush) and Ctb (control toothbrush)" Comment: despite the efforts made to ensure blinding of outcome assessment, the higher level of tooth staining in the CHX rinse group meant that examining clinicians could not be adequately blinded and this could have affected the outcome assessment. The direction of this potential bias is unclear
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition: all arms: 10/150 (6.7%). By group: CHX rinse 3/50 (6.0%), template control brush 3/50 (6%). Reasons for losses not broken down by group. Subjects lost after randomisation and before baseline examination: 4 were disqualified, 4 refused to participate and 2 were excluded for other reasons Comment: all losses were after randomisation before the start of the trial. They were balanced across groups
Selective reporting (reporting bias)	Low risk	All outcomes stated in the methods sections were reported in the results section
Other bias	Low risk	Quote: "Both examiners were well‐trained and had been involved in previous studies." Calibration is not mentioned There was no statistically significant difference in mean age, or whole mouth plaque and gingival bleeding levels