Bleaching versus color change resistant adhesive in the discoloration of bracket-bonded tooth surfaces: an in vitro study.

OBJECTIVES: The aim of this study was to compare the effect of office bleaching of teeth bonded with Transbond XTTM (3M Unitek, Monrovia, CA, USA) (TRXT) and the use of color change resistant Orthocem (FGM, Joinville, Brazil) in bracket bonding on coffee-induced enamel discoloration. MATERIALS AND METHODS: Eighty premolars were distributed in equal numbers (n = 20) to group 1 (TRXT + distilled water), group 2 (TRXT + coffee solution), group 3 (TRXT + coffee solution + bleaching), and group 4 (Orthocem + coffee solution). Color was measured using a SpectroShade Micro (MHT, International, Verona, Italy) device at the beginning (T0), after coloring (T1), after bleaching (T1B), and after debonding (T2). ΔE color change values were calculated as T1-T0, T1B-T0 and T2-T0 differences. The conformity of the data to the normal distribution was examined with the Shapiro-Wilk test. Multiple comparisons were made with Tamhane's T2 test and Tukey's HSD test using one-way analysis of variance in the comparison of normally distributed data, and multiple comparisons were made with Dunn's test using the Kruskal-Wallis H test for comparison of non-normally distributed data. The significance level was set at p < 0.050. RESULTS: A statistically significant (p < 0.001) difference was found between the T1-T0 and T2-T0 stages for group 1-4 ΔE values. A statistically significant (p < 0.001) difference was also found when the T1B-T0 ΔE values of group 3 were compared with the T1-T0 ΔE values of groups 1, 2, and 4. CONCLUSIONS: After coffee-induced enamel discoloration, bleaching of teeth bonded with TRXT produced acceptable color difference of the incisal, middle, and gingival regions of the crown. In teeth bonded with Orthocem, acceptable color difference was seen only in the middle of the crown. CLINICAL RELEVANCE: The presented study will guide the clinician on how enamel discoloration side effect of fixed orthodontic appliance can reduce.

Bonded lingual retainer adhesives and discoloration : An in vitro study.

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™ Flow [GCO], GC Orthodontics, Tokyo, Japan); group 2, highly filled composite adhesive (Transbond™ LR [TLR], 3M Unitek, Monrovia, CA, USA); and group 3, highly filled composite adhesive with liquid polish (TLR and BisCover LV™ [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 ∆L*, ∆a*, ∆b*, and ∆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 ∆E*ab (P = 0.007). ∆E*ab value of TLR group was greater than ∆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 ∆a*. ∆a* values of GCO and TLRB groups were greater than ∆a* value of TLR group. The difference between the TLR and TLRB groups was statistically significant (p = 0.003) for ∆b*. ∆b* value of TLR group was greater than ∆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.