Objectives: To compare the stability, durability, oral hygiene maintenance and periodontal status of a resin-bonded polyethylene ribbon retainer and a removable retainer. Methods: Twenty patients (20) who have completed comprehensive orthodontic treatment were randomly assigned to either the resin-bonded polyethylene ribbon (Ribbond Orthodontic-THM) retainer or the removable Essix retainer that served as the control. The 1mm ribbon was bonded to the lingual surface of mandibular anterior teeth using a resin material (Transbond LR, 3M-Unitek). Essix retainer was constructed from thermoforming on patient's cast. Patients in the removable group were instructed to wear the retainer for 12 hours per day and both groups were given appliance maintenance and oral hygiene instructions. Irregularity Index, arch length and inter-canine width were measured from study casts taken at pre-treatment, post-treatment, 3 months and 6 months follow-up visits. Appliance durability, plaque scores, gingival bleeding incidence (BOP) and periodontal status were recorded clinically. Repeated measures ANOVA and multiple comparison tests were used to determine differences among retainer type, time and interactions with each measured parameter. Results: There is a significant interaction (p<0.0001) between retainer type and time for Irregularity Index and inter-canine width. Essix showed significant increase in irregularity Index (0.4mm) and decrease in inter-canine width (0.5mm) throughout the study, compared to 0.06mm and 0.02mm respectively in the Ribbond group (p<0.05). Mean BOP was significantly higher in the bonded group (3.4 ± 0.37) compared to the control (1.9 ± 0.38)(p=0.0008). Conclusions: These results suggest that removable retainers does not attain stability in retention as readily, but additional attention to oral hygiene is necessary with bonded retainers.

Back to the Dental Materials: VIII - Others-Non-metallic Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)

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