Spectrophotometric investigation of the effect of different adhesives and office-type bleachi̇ng on enamel discoloration in bracketed teeth: an in vitro study

Aim: The aim of this in vitro study is to compare the effects of two different orthodontic bonding adhesives and in-office type bleaching on bonded teeth on enamel discoloration after debond with spectrophotometric examination. Material and Method: 80 human premolar teeth were divided into four groups according to the adhesives with which the brackets were bonded, the bleaching application and staining solutions: Group 1, highly filled composite adhesive and distilled water (Transbond XT=TRXT+DS); Group 2, highly filled composite adhesive and coffee solution (Transbond XT=TRXT+KH); Group 3 consisted of highly filled composite adhesive and coffee solution followed by office bleaching (Transbond XT=TRXT+ KH +Opalacence Boost) and Group 4, resistant to discoloration no primer adhesive and coffee solution (Orthocem=OC + KH). The L*a*b* values of the teeth were measured with Spectro Shade Micro device before bracket bonding (T0), after they were stored in solution (T1), after bleaching for Group 3 (T1B) and after debonding (T2) in all groups. Measurements were made separately for the incisal, middle and gingival regions of the crown, and ΔE values were calculated using the T1-T0, T1B-T0 and T2-T0 differences. The conformity of the obtained data to the normal distribution was examined with the Shapiro-Wilk test. Tamhane's T2 test and Tukey HSD test were used to compare normally distributed data, Kruskall Wallis H test was used to compare data that were not normally distributed, and multiple comparisons were examined with Dunn's test. Analysis results were presented as mean ± standard deviation and median (minimum–maximum). Significance level was taken as p<0.050 Results: In comparisons between groups, ΔE values of Group 1 at T1-T0 and T2-T0 stages were compared to ΔE values of Groups 2, 3 and 4, incisal (p<0.001), middle (p<0.001) and gingival (p<0.001) was statistically significantly lower in the regions. ΔE values of Group 3 at T2-T0 stage were statistically significantly lower in the middle (p<0.001) and gingival (p<0.001) regions compared to Group 2. There was no statistically significant difference between the ΔE values of Group 4 and the ΔE values of Group 2 and Group 3 at the T2-T0 stage (p>0.050). Conclusion: In order to keep the coffee-induced discoloration of the enamel after debond at a clinically acceptable level, applying Opalacence Boost whitening to the bracketed teeth bonded with Transbond XT is more effective than using Orthocem or Transbond XT as the bonding adhesive.