Failure evaluation after a 6-year retention period: A comparison between glass fiber0reinforced (GFR) and multistranded bonded retainers

Objectives: The aim of this study was to compare bond failure and breakage rates of two types of bonded lingual orthodontic retainers (GFR and .0175" multistranded stainless steel wire [MST]) after a 6-year retention period. Subjects and methods: Eighty-five young adults were randomly divided into two groups: 40 subjects received 48 GFR retainers (14 maxillary and 34 mandibular retainers), and 45 subjects received 50 MST retainers (18 maxillary and 32 mandibular retainers). A Fisher's exact test was performed in order to identify significant differences in the percentage of detachment and breakage of the retainers between the groups. Results: The maxillary detachment rates were 21.42% for the GFR group and 22.22% for the MST group; the mandibular detachment rates were 11.76% for the GFR group and 15.62% for the MST group. The maxillary breakage rates were 7.14% for the GFR group and 16.66% for the MST group; the mandibular breakage rates were 8.82% for the GFR group and 15.62% for the MST group. The differences were not statistically significant. Conclusion: GFR and multistranded stainless steel retainers showed similar results in terms of bond failure and breakage after 6 years of retention. The use of GFR retainers as a retention strategy should not be discouraged and could be considered a viable esthetic alternative to stainless steel wire retainers. (C) 2011 CEO. Published by Elsevier Masson SAS. All rights reserved