Evaluation and Comparison of Clinical Bracket Failure Rate of a New Orthodontic Adhesive Modified with Silver Nanoparticles with Conventional Orthodontic Adhesive: An In Vivo Study

Background It is essential to use orthodontic composites that possess favorable properties specifically; those that can be easily removed at the end of treatment but remain securely bonded during the course of treatment. Nanoparticles have gained attention for their antibacterial effects when incorporated into composite resins. However, the impact of nanoparticle incorporation in the adhesive and its relation with bracket failure rate has not been widely explored. Aim The aim of this study was to evaluate and compare clinical bracket failure rate of orthodontic adhesive modified with silver nanoparticles (AgNPs) with conventional orthodontic adhesive without AgNPs. Materials and Methods This in vivo study included patients aged between 15 and 35 years with mild-to-moderate crowding and healthy periodontium, requiring fixed orthodontic treatment with 0.022” × 0.028” slot metal brackets. Synthesis of colloidal AgNPs was performed using sodium tetrahydridoborate (NaBH 4 ) as the reducing agent. 0.09% w/w of AgNP were manually mixed in one syringe of orthodontic adhesive (3M Unitek Transbond XT) using mortar and pestle. Twenty patients (10 each group) were selected who met the inclusion criteria and allocated to the control and experimental groups using the lottery method. A total of 195 teeth (96 control, 99 experimental) were bonded. Brackets in the experimental group used adhesive (3M Transbond XT) modified with AgNP, while the control group used conventional adhesive (3M Transbond XT). Bracket failure rate was recorded over 4.5 months. The wire sequence used was 0.012 Niti, 0.016 Niti, 0.018 SS, 17x25 Niti, 19x25 Niti, and lastly 19x25 SS. Descriptive statistics, Kaplan–Meier plots, and log-rank tests were used to compare failure rates. Result Bracket failure rates were assessed using the Kapla–Meier plots which showed the survival (failure) rate of control and experiment group being 81.3% and 82%, respectively. There is no statistically significant difference in survival estimates of control and experimental group. Both survival curves start at 100% and show minimal decline across the 140-day period. The debonding occurred more on the initial aligning wires, that is, 0.016 Niti (control group) and 0.012 Niti (experimental group) between 24 and 75 days in average. Rate of bracket failure was higher in posterior teeth (15%) as compared to anterior teeth (3%). Conclusion The study found that orthodontic adhesive containing AgNP exhibited a 0.7% lower bracket failure rate compared to conventional adhesive. Bracket failures were more frequent in posterior teeth than anterior teeth. Further long-term studies with larger sample sizes are recommended to validate the effectiveness of AgNPs in orthodontic adhesives.