An evaluation and comparison of frictional resistance, surface roughness, and microbial colonization of silver-coated and uncoated stainless steel archwires – An <i>in vivo</i> study

Objectives: When undergoing fixed orthodontic treatment, white spot lesions and caries are frequently observed. The silver coating on brackets, archwires, and bands can help prevent these conditions. However, this might have an impact on friction and the oral environment, which would then impact the movement of the teeth. Thus, this study was taken up to evaluate and compare the frictional resistance, surface roughness, and microbial colonization of silver-coated and uncoated stainless steel archwire. Material and Methods: The investigation contained sixty samples, with 30 samples in each sub-group. Group 1 included 30 samples of 0.019 × 0.025” stainless steel wires coated in silver nanoparticles and Group 2 included 30 uncoated 0.019 × 0.025” stainless steel wires. A thermal vacuum evaporation technique was used to coat the wire with a 10 nm layer of coating. After placing the wire for 6 weeks in the oral cavity, it was retrieved and evaluated for frictional resistance, surface roughness, and microbial colonization. Results: After comparing the friction across the groups, the results did not show statistically significant differences. Scanning electron microscopy revealed that the surface roughness of wires coated in silver was lesser compared to the wire’s uncoated segment. As for the microbial colonization, Streptococcus mutans and Lactobacillus acidophilus showed reduced growth in the silver-coated portion. Conclusion: It can be concluded that silver coating does not alter the frictional properties of the wire. In the archwire’s silver-coated part, the surface roughness was lower. The silver coating showed significant anti-bacterial activity.