Monetary incentives for improving smartphone-measured oral hygiene behaviors in young children: A randomized pilot trial

PLoS One. 2020 Jul 30;15(7):e0236692. doi: 10.1371/journal.pone.0236692. eCollection 2020.


Aims: To assess feasibility, acceptability, and early efficacy of monetary incentive-based interventions on fostering oral hygiene in young children measured with a Bluetooth-enabled toothbrush and smartphone application.

Design: A stratified, parallel-group, three-arm individually randomized controlled pilot trial.

Setting: Two Los Angeles area Early Head Start (EHS) sites.

Participants: 36 parent-child dyads enrolled in an EHS home visit program for 0-3 year olds.

Interventions: Eligible dyads, within strata and permuted blocks, were randomized in equal allocation to one of three groups: waitlist (delayed monetary incentive) control group, fixed monetary incentive package, or lottery monetary incentive package. The intervention lasted 8 weeks.

Outcomes: Primary outcomes were a) toothbrushing performance: mean number of Bluetooth-recorded half-day episodes per week when the child's teeth were brushed, and b) dental visit by the 2-month follow-up among children with no prior dental visit. The a priori milestone of 20% more frequent toothbrushing identified the intervention for a subsequent trial. Feasibility and acceptability measures were also assessed, including frequency of parents syncing the Bluetooth-enabled toothbrush to the smartphone application and plaque measurement from digital photographs.

Findings: Digital monitoring of toothbrushing was feasible. Mean number of weekly toothbrushing episodes over 8 weeks was 3.9 in the control group, 4.1 in the fixed incentive group, and 6.0 in the lottery incentive group. The lottery group had 53% more frequent toothbrushing than the control group and 47% more frequent toothbrushing than the fixed group. Exploratory analyses showed effects concentrated among children ≤24 months. Follow-up dental visit attendance was similar across groups. iPhone 7 more reliably captured evaluable images than Photomed Cannon G16.

Conclusions: Trial protocol and outcome measures were deemed feasible and acceptable. Results informed the study protocol for a fully powered trial of lottery incentives versus a delayed control using the smart toothbrush and remote digital incentive program administration.

Trial registration: identifier NCT03862443.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Child, Preschool
  • Dental Care for Children*
  • Dental Plaque / diagnosis
  • Dental Plaque / pathology
  • Dental Plaque / prevention & control
  • Dental Plaque Index
  • Female
  • Humans
  • Infant
  • Male
  • Mobile Applications
  • Parents / psychology
  • Pilot Projects
  • Reward*
  • Toothbrushing* / instrumentation
  • Toothbrushing* / methods

Associated data