Mederios 2008.
| Methods | Title: effectiveness of nightguard vital bleaching with 10% carbamide peroxide Trial design: randomised controlled trial Location: Universidade Federal do Rio Grande do Norte, Brazil Language: English Number of centres: 1 Recruitment period: not reported Funding source: not reported |
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| Participants | Participants: university students. 18 to 25 years old. Mean age 21.6 years Total number: 50 Inclusion criteria:
Exclusion criteria: not reported Number randomised: 50 Method of randomisation: raffle Method of allocation concealment: not reported. Patients were randomly allotted to either group Method of blinding: the placebo was placed in empty Opalescence PF packaging so that neither the volunteer nor the examiner knew which gel was being used Number evaluated: 49 |
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| Interventions | Total number of intervention groups: 2 10% carbamide peroxide gel in tray Placebo Duration of treatment: 21 days |
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| Outcomes | Change in tooth shade: Vita shade guide ‐ arranged from lightest to dark (1 light and 16 darkest) Gingival Bleeding Index modified by Lang Tooth sensitivity: yes or no Patient satisfaction: satisfactory or non‐satisfactory |
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| Notes | Sample size calculation: not reported Adverse effects: tooth sensitivity and gingival bleeding Health‐related quality of life: reported Key conclusions of the study authors: "NGVB with 10% carbamide peroxide, when use in the current study, was effective for lightening tooth colour, both for the period immediately after treatment and for the 6‐month follow‐up period. Of the 2 main side effects assessed, tooth sensitivity was more prevalent than gingival irritation" Contact: Dr Medeiros; cristinamedeiros@digizap.com.br |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "In a simple raffle, the 50 volunteers were randomly allocated to 1 of the 2 groups.." |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Quote: "The placebo gel had the same physical characteristics as the experimental gel. The placebo was placed in empty Opalescence PF packaging so that neither the volunteer nor the examiner knew which gel was being used" |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Quote: "All analysis were done by the evaluator" Comment: but it is not mentioned whether the same evaluator dispensed the gel or not |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Quote: "All volunteers completed the study.... The data of 1 volunteer from the placebo group were lost because of upper right lateral incisor anodontia" Comment: plausible effect size (difference in means) among missing outcomes not enough to have a clinically relevant impact on observed effect size |
| Selective reporting (reporting bias) | Low risk | All outcomes described are reported. Conclusions are in accordance with the results |
| Other bias | Low risk | None |