Navarra 2014.

Methods	Title: effects of 2 10% carbamide peroxide Nightguard bleaching agents, with and without desensitizer, on enamel and sensitivity: an in vivo study Trial design: blinded, randomised controlled trial Location: not reported Language: English Number of centres: 1 Recruitment period: not reported Funding source: supported, in part, by grants from MIUR (Italy)
Participants	Participants: 20 to 50 years old. Mean age 25.3 years Total number: 80 Inclusion criteria: not reported Exclusion criteria: smoking, pregnancy or breastfeeding history of previous bleaching treatment dentine hypersensitivity caused by caries lesions fracture of restorations, chipped teeth, marginal gaps, post‐operative sensitivity teeth with cervical fillings, and recent use of desensitizing toothpaste Number randomised: 20 Method of randomisation: not reported Method of allocation concealment: reported Method of blinding: not reported Number evaluated: 20
Interventions	Total number of intervention groups: 2 10% carbamide peroxide with fluoride and potassium nitrate in tray 10% carbamide peroxide without desensitizing agents in tray Duration of treatment: 2 weeks
Outcomes	Improvement in tooth colour ΔL, a*, b*, ΔW values were recorded. Increase in ΔL and reduction in b* indicated whitening
Notes	Sample size calculation: not reported Adverse effects: sensitivity Key conclusions of the study authors: "The use of 10% carbamide peroxide gel with fluoride and potassium nitrate reduced the incidence of sensitivity during the bleaching treatment compared to a bleaching agent that did not contain desensitizing agents. The bleaching effectiveness of the tested products was comparable" Correspondence required: no Contact: M Cadenaro, m.cadenaro@fmc.units.it
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "An operator not involved in the research protocol performed the randomisation." However, method of randomisation is not reported
Allocation concealment (selection bias)	Low risk	Quote: "allocated groups were recorded on cards contained in sequentially numbered, sealed envelopes that were blindly assigned"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "blinded randomised controlled trial." However, method of blinding is not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "blinded randomised controlled trial." However, method of blinding is not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts
Selective reporting (reporting bias)	Low risk	All outcomes described were reported. Conclusions are in accordance with the results
Other bias	Low risk	None