Bonded Lingual Retainer Adhesives and Discoloration

Abstract

Purpose This in vitro study was conducted to compare the discoloration of a flowable self-adhesive composite, a highly filled composite adhesive, and a liquid polish applied highly filled composite adhesive for bonded lingual retainers. Methods Thirty composite discs were fabricated and divided into three groups: group 1, flowable self-adhesive (GC Ortho Connect (TM) Flow [GCO], GC Orthodontics, Tokyo, Japan); group 2, highly filled composite adhesive (Transbond (TM) LR [TLR], 3M Unitek, Monrovia, CA, USA); and group 3, highly filled composite adhesive with liquid polish (TLR and BisCover LV (TM) [TLRB], BISCO Inc, Schaumburg, IL, USA). L*a*b* values were measured by spectrophotometer prior to (T0) and following (T1) immersion in coffee. T1-T0 differences were calculated as Delta L*, Delta a*, Delta b*, and Delta E*ab values. The Shapiro-Wilk test was performed to determine whether the data were normally distributed. The values that did not fit the normal distribution were evaluated with the Kruskal-Wallis one-way analysis of variance (ANOVA), and Dunn's test was used for multiple comparisons. The level of significance was p< 0.05. Results The difference between the TLR and TLRB groups was statistically significant for Delta E*ab (P= 0.007). Delta E*ab value of TLR group was greater than Delta E*ab value of TLRB group. The differences between the GCO and TLR groups (p= 0.001) and the TLR and TLRB groups (p= 0.010) were statistically significant for Delta a*. Delta a* values of GCO and TLRB groups were greater than Delta a* value of TLR group. The difference between the TLR and TLRB groups was statistically significant (p= 0.003) for Delta b*. Delta b* value of TLR group was greater than Delta b* value of TLRB group. Conclusions Using a Transbond LR polished with BisCover LV or only GC Ortho Connect Flow for lingual retainer bonding reduces coffee-induced discoloration.