Gingival health and relapse tendency: a prospective study of two types of lower fixed retainers

Abstract

Abstract Background Different types and diameters of wire are used in bonded lingual retainers. Some clinicians bond a small diameter multistrand wire to each tooth, while other clinicians bond a large diameter wire to the lingual surfaces of the lower canines. Aim To compare the gingival health, plaque accumulation, tooth stability and integrity of multistrand wire and round wire bonded lingual retainers. Methods Sixty-two subjects, who had completed treatment and who required fixed retention for the lower anterior segment, were assigned to either the Round wire retainer group or the Multistrand wire retainer group. In the Round wire retainer group, a 0.036 inch round, stainless steel wire was bonded to the lingual surfaces of both lower canines. The Multistrand retainer group had a 0.015 inch multistrand wire bonded to the lingual surfaces of all lower anterior teeth. At least 12 months after debonding, the subjects were recalled and the following variables were recorded: Oral Hygiene Index (OHI), Plaque Index (PI) of the lower anterior teeth, Gingival Index (GI) of the lower anterior teeth, Irregularity Index (IRI) of the lower anterior teeth, and the number of broken retainers. Results There were no significant differences between the PI (p = 0.165) and GI (p = 0.150) of the two groups. More plaque was found on the distal surfaces of the lower anterior teeth in the group with multistrand wire retainers (p = 0.02). The lower anterior teeth were significantly more irregular in the group with round wire retainers compared to the group with multistrand wire retainers (p = 0.002). Although the multistrand wire retainers fractured more frequently than the round wire retainers the difference was not statistically significant (p = 0.325). Conclusion More plaque accumulated on the distal surfaces of the lower anterior teeth in subjects with multistrand wire retainers than in subjects with round wire retainers. Multistrand wire retainers were better at maintaining incisor alignment than single span, round wire retainers.