| dc.description.abstract | Failure of bracket adhesion to the enamel surface remains one of the challenges in fixed orthodontic treatment. Previous studies have stated that the incidence of bracket bond failure is multifactorial, but it is often associated with improper bonding procedures. The aim of this study was to investigate the effect of adding nanochitosan powder at varying concentrations on the shear bond strength of orthodontic brackets. Four groups were prepared by adding nanochitosan powder at concentrations of 0%, 10%, 15%, and 20% into American Orthodontics BracePaste MTP Primer. Twenty-eight extracted maxillary and mandibular premolars (right/left) were bonded with stainless steel brackets to the enamel surface according to a standardized procedure. The samples were then immersed in artificial saliva and stored in an incubator at 37°C for 7 days. Shear bond strength testing of the orthodontic brackets was performed using a Universal Testing Machine. Data were analyzed using One-Way ANOVA and LSD tests. The mean shear bond strength in the group without nanochitosan powder was 5.325±0.119 MPa, with 10% nanochitosan addition was 5.727±0.554 MPa, with 15% was 8.130±0.406 MPa, and with 20% was 15.425±0.535 MPa. Statistical analysis showed a significant difference among all treatment groups (p<0.05). The addition of nanochitosan powder to the adhesive primer significantly increased the shear bond strength of orthodontic brackets in comparisons between the control group (without nanochitosan) and the 15% nanochitosan group, the control group and the 20% nanochitosan group, the 10% and 15% nanochitosan groups, the 10% and 20% nanochitosan groups, as well as the 15% and 20% nanochitosan groups. No significant difference was observed between the control group and the 10% nanochitosan group. | en_US |
