RESUMEN
OBJECTIVE: To establish whether the use of a WaterPik® alongside a manual toothbrush (WaterPik® + MTB) is more effective for maintaining oral hygiene compared to the use of a manual toothbrush alone (MTB) in patients wearing fixed orthodontic appliances. DESIGN: A single-centre, two-arm, parallel-group, single-blind, randomised controlled clinical trial with a 1:1 allocation ratio. SETTING: Orthodontic department at York Hospital, York Teaching Hospitals NHS Foundation Trust, UK. PARTICIPANTS: A total of 40 fit and well participants, aged 10-20 years, being treated with upper and lower fixed orthodontic appliances. METHODS: Participants were randomly allocated, using stratified block randomisation, to the control group (MTB) or intervention group '(Waterpik® + MTB)'. Plaque, gingival and interdental bleeding indices were recorded at baseline, 8 weeks, 32 weeks and 56 weeks. A generalised linear mixed model was used to assess differences between groups. RESULTS: An interim analysis of results was performed with 40 patients recruited and 85% of data collected. The overall mean differences between the groups were as follows: plaque index = 0.199 (P = 0.88, 95% confidence interval [CI] -0.24 to 0.27); gingival index = -0.008 (P = 0.94, 95% CI -0.22 to 0.20); and interdental bleeding index = 5.60 (P = 0.563, 95% CI -13.22 to 24.42). No statistical difference between the two groups was found for any variable. The trial was stopped at this point. CONCLUSIONS: In terms of oral hygiene, our study did not find evidence to support the claim of benefit of using a Waterpik® in addition to a manual toothbrush for patients wearing fixed orthodontic appliances.