Evaluation of the effectiveness of a tailored mobile application in increasing the duration of wear of thermoplastic retainers: a randomized controlled trial

Abstract

BACKGROUND: The 'My Retainers' mobile application is a patient-informed intervention designed to enhance removable retainer wear and associated patient experiences during the retention phase. OBJECTIVES: To evaluate the effect of receiving the 'My Retainers' application on objectively assessed thermoplastic retainer (TPR) wear time, stability, periodontal outcomes, patient experiences, and knowledge related to retainers. MATERIALS AND METHODS: Eighty-four participants planned for removable retention with TPRs were assigned either to receive the 'My Retainers' application or to control not receiving electronic reminders during the 3-month period. Randomization was based on computer-generated random numbers and allocation was concealed using opaque, sealed envelopes. The primary outcome was objectively assessed retainer wear recorded using an embedded TheraMon® micro-electronic sensor. Secondary outcomes, including irregularity of the maxillary and mandibular incisors, plaque levels, bleeding on probing and probing depth, were assessed at baseline and 3-month follow-up; and analysed using a series of mixed models. Experiences and knowledge related to orthodontic retainers were recorded using questionnaires. The outcome assessor was blinded when possible. RESULTS: Receipt of the mobile application resulted in slightly higher median wear time (0.91 hours/day); however, this difference was not statistically significant (P = 0.56; 95% confidence interval [CI]: -2.19, 4.01). No significant differences were found between the treatment groups in terms of stability (P = 0.92; 95% CI: -0.03, 0.04), plaque levels (P = 0.44; 95% CI: -0.07, 0.03), bleeding on probing (P = 0.61; 95% CI: -0.05, 0.03) and probing depth (P = 0.79; 95% CI: -0.09, 0.07). Furthermore, similar levels of patient experiences (P = 0.94) and knowledge related to retainers (P = 0.26) were found. However, marginally better levels of knowledge were identified in the intervention group. No harms were observed. LIMITATIONS: A relatively short follow-up period with the study confined to a single-center in a university-based hospital. CONCLUSIONS: Provision of the bespoke 'My Retainers' application did not lead to an improvement in adherence with TPR wear over a 3-month follow-up period. Further refinement and research are required to develop and investigate means of enhancing adherence levels. CLINICAL REGISTRATION: NCT03224481.