The study will involve a 10-week Micro-Randomized Trial (MRT) to inform the delivery of prompts (via mobile app push notifications) designed to facilitate adherence to an ideal tooth brushing protocol (2x2x4; 2 sessions daily, 2 minutes per session, all 4 quadrants).

The goal of the MRT is to investigate whether delivering (vs. not delivering) a prompt that contains engagement strategies grounded in decision science is beneficial in terms of promoting proximal oral health behavior (OHB) score, which reflects adherence to the 2x2x4 brushing protocol (Primary Aim) and also mobile health engagement (mHealth; Secondary Aim). Additionally, Exploratory Aims will concern (a) comparing different types of prompts in terms of proximal OHB score and mHealth engagement, (b) investigating the conditions in which prompts should be delivered to most effectively promote proximal OHB and mHealth engagement; and (c) investigating whether the effect of the engagement prompts (vs. no prompt) on OHB score varies across components of the 2x2x4 brushing regimen (i.e., frequency, duration, or coverage).

Participants will receive an electronic toothbrush (eBrush) and a mobile app (Oralytics) that contains well-established behavior change strategies (e.g., goal setting, monitoring adherence, and feedback). Participants will be randomized twice per day - in the morning and the evening - to receive either (a) a push notification containing one of three (randomly selected) engagement strategies or (b) no notification.

During the 10 weeks of the study, a Bayesian algorithm will iteratively adjust the probability of receiving a prompt or no prompt in any given randomization window, using prior behavioral data collected through the eBrush and mobile app. Data patterns suggesting positive effects of the prompts on adherence to brushing protocol, especially duration, will result in higher subsequent probabilities of receiving the prompts, whereas patterns suggesting null or negative effects will result in lower probabilities of receiving the prompts.

Study results will inform the implementation of a smartphone-delivered behavior change intervention that further adapts the delivery of engagement prompts based on passively collected information from an eBrush and the mobile app.

Inclusion Criteria:

• Adults, age 18 or older.
• Fluent in English
• Dentulous/partially edentulous (18+ teeth; at least 2 teeth in each quadrant)
• Possess a smartphone (iOS or Android) with a data plan.
• Willing to allow the passive collection of data on tooth-brushing activities in the home setting for 10 weeks.

Exclusion Criteria:

• Not fluent in English
• Edentulous
• Unable to use a mobile device due to cognitive or physical impairments

A de-identified dataset will be generated and made available to the research community. The dataset will be stripped of all codes or any other information that could be linked back to the original data or an individual participant. Prospective users of this dataset must agree to a confidentiality agreement and get permission from the Primary Investigator to use or share the data with anyone else. All external requests for data will be directed to Dr. Vivek Shetty. Prospective investigators will submit a written proposal to the PI outlining the question they will investigate, the specific variables that they need to answer that question, their analytic plan for answering that question, and documentation of sufficient Institutional Review Board oversight (e.g., approval or exemption). Investigators will also need to sign a confidentiality agreement.

12 months after publication of primary analyses.

All external requests for data will be directed to the PI (Dr. Vivek Shetty). Prospective investigators will submit a written proposal to the PI outlining the question they will investigate, the specific variables that they need to answer that question, their analytic plan for answering that question, and documentation of sufficient Institutional Review Board oversight (e.g., approval or exemption). Investigators will also need to sign a confidentiality agreement.