Kose 2011.

Methods	Title: clinical effects of at‐home bleaching along with desensitizing agent application Trial design: randomised, double‐blinded, controlled trial Location: University Estadua, Brazil Language: English Number of centres: 1 Recruitment period: not reported Funding source: FGM Dental Products
Participants	Participants: 18 to 30 years old. Mean age 24 years Total number: 60 Inclusion criteria: 18 and older 6 caries and restoration free teeth A2 shade or darker Exclusion criteria: previous vital bleaching, apparent caries, periodontal disease orthodontic appliances, anterior restorations history of dentine hypersensitivity bruxism Number randomised: 60 Method of randomisation: coin toss Method of allocation concealment: not reported Method of blinding: similar syringes Number evaluated: 60
Interventions	Total number of intervention groups: 2 16% carbamide peroxide in tray + placebo 16% carbamide peroxide in tray + desensitizer gel (DG; 5% potassium nitrate and 2% sodium fluoride) Duration of treatment: 4 weeks
Outcomes	Improvement in tooth shade: Vita shade guide B1 (highest) to C4 (lowest) Tooth sensitivity: 0 ‐ none, 1 – mild, 2 ‐ moderate, 3 ‐ considerable, 4 ‐ severe
Notes	Sample size calculation: not reported Adverse effects: tooth sensitivity Health‐related quality of life: not reported Key conclusions of the study authors: "The use of desensitizing agent did not affect the bleaching efficacy of the CP. The prevalence and intensity of tooth sensitivity was similar for both groups. However, participants from the placebo group had sensitivity in 33.6% of the bleaching days, which was significantly higher than the desensitizing agent experimental group (20.1%)" Correspondence required: no Contact: Dr Kose, School of Dentistry, State University of Ponda, Santa Catarina, Brazil
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "subjects were randomly divided into experimental or control group by coin toss"
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Neither the subjects nor the evaluators knew to which group the subjects were assigned"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Neither the subjects nor the evaluators knew to which group the subjects were assigned"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "All 60 participants who began study completed the study"
Selective reporting (reporting bias)	Low risk	All outcomes described were reported. Conclusions are in accordance with the results
Other bias	Low risk	None