Procedures
®
PLAQUE
A total of fifty-two participants each receiving a Hawley retainer with embedded TheraMon® microsensor (MC Technology GmbH, Hargelsberg, Austria) were randomly allocated to receive either (A) audiovisual instructions and electronic weekly reminder (Audiovisual group) or (B) verbal only instructions (control group). Permuted block randomization ensuring 1:1 allocation ratio (block size = 4) was performed by independent personnel using a computer-generated number list. Allocation was concealed by using sequentially sealed opaque envelopes.In debonding visit, all participants received standardized oral hygiene instructions with scaling and polishing procedures. Participants were instructed to temporarily wear a 1 mm thickness maxillary and mandibular vacuum-formed retainers (ACE®, DENTSPLY) for 3–4 days for 22 h each day until the Hawley retainer was manufactured. Standardized laboratory steps were undertaken by one experienced technician. Microsensors were embedded totally in the maxillary posterior palatal region of the acrylic covering (Palapress®; Kulzer GmbH, Mitsui Chemicals, Hanau, Germany) (Fig. Microsensor embedded in upper removable Hawley retainer.At recall appointment (T0), participants in both groups were instructed to wear the Hawley retainer on a full-time basis for 22 daily hours for 6 months, with two follow-up visits after 3 months (T1), and 6 months from the start of retention (T2). Hawley retainer microsensor was activated at the same visit, by using a pen reader through an onboard antenna to the laptop, with attached TheraMon® client software (version 1.3.0.4, MC Technology GmbH, Hargelsberg, Austria). The microsensor was adjusted to monitor compliance wear within temperature range from 33.5 to 38.5 °C (attributable to variations in intra-oral temperature) every 15 minutesDaily wear times (in hours) over the 3-month period, upper graph shows sub-optimal compliance with 10 h of wear, lower graph shows a compliant patient with 23 h of daily wear.Participants’ gingival and plaque indices were recorded and compared at T0 and T2. Maxillary and mandibular periodontal measures were measured on all surfaces of indexed teeth 16, 36, 12, 32, 24/25, 44/45 to be a representative of the full dentitionParticipants completed an additional questionnaire at T2; the questionnaire assessed participants’ experiences and satisfaction with the Hawley retainer. Questionnaires were based on perspectives of the NHS, and patients’ subjective experiences