Kihn 2000.
| Methods | Title: a clinical evaluation of 10% versus 15% carbamide peroxide tooth whitening agents Trial design: randomised, double‐blinded study Location: University of Maryland Dental School, USA Language: English Number of centres: 1 Recruitment period: not reported Funding source: Dentsply |
|
| Participants | Participants: 18 to 65 years old Total number: 57 Inclusion criteria: maxillary anterior teeth of shade A3 or darker Exclusion criteria: not reported Number randomised: 56 Method of randomisation: reported Method of allocation concealment: not reported Method of blinding: not reported Number evaluated: 52 |
|
| Interventions | Total number of intervention groups: 2 Experiment: 15% carbamide peroxide gel Control: 10% carbamide peroxide gel Duration of treatment: 2 weeks |
|
| Outcomes | Improvement in tooth colour Sensitivity: 0 (no pain) to 20 (severe) |
|
| Notes | Sample size calculation: not reported Adverse effects: sensitivity Health‐related quality of life: not reported Key conclusions of the study authors: "There was a significant difference in colour change between the 10% CP and 15% CP groups at the end of the study period. There was no significant difference in level of tooth sensitivity between the 2 groups, and the incidence was equal; there was, however, a significant difference in variability of tooth sensitivity between the 2 groups" Correspondence required: no Contact: Patricia W Kihn; tkihn@caulk.com |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "paired list of names was supplied to the manufacturer, which then randomly assigned 1 member of each pair" |
| Allocation concealment (selection bias) | Unclear risk | Not mentioned |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Quote: "authors conducted a double‐blinded study of human subjects to..." However, method of blinding is not reported |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Quote: "authors conducted a double‐blinded study of human subjects to..." However, method of blinding is not reported |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Quote: "Of the 56 subjects who began the study, 26 pairs of matched subjects (n = 52 individual subjects) completed the study" Commnet: missing outcome data balanced in numbers across intervention groups |
| Selective reporting (reporting bias) | Low risk | All outcomes described were reported. Conclusions are in accordance with the results |
| Other bias | Low risk | None |