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

Abstract

The 'My Retainers' mobile application is a patient-informed intervention designed to enhance removable retainer wear and associated patient experiences during the retention phase. 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. 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. 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. A relatively short follow-up period with the study confined to a single-center in a university-based hospital. 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. NCT03224481.